The Dynamic Earth

Sed Structure Sunday - Adhesion Ripples!

2012-01-15T09:39:00.000-08:00

As previously mentioned, my visit to Sandy Hook in New Jersey was on a pretty damn windy day. Big, 40 mph gusts were walloping the beach, coming in obliquely off the sea an onto the sandy foreshore. These winds were mobilizing a LOT of material, saltating medium-grained sands along the damp shoreline, producing a perfect opportunity to catch some pretty neat eolian sedimentary structures. Behold! Adhesion Ripples (Camera case for scale)!

Adhesion ripples are formed when dry, wind blown sand gets glommed onto a wet, sticky surface; the fancy word for such glommification is "adhesion", et viola: Adhesion Ripples! They differ from the traditional ripple cross-laminated sands in a variety of important ways, the most fundamental difference being that there isn't any evidence for the traditional grain-flow structure in the laminations, which would be expected if these structured formed as part of a migrating bedform. More qualitatively, these structures just seem weird, with chunks and bits stuck onto a wavy surface in a way that just LOOKS different from the directional migration of sedimentary structures.

Kocurek and Fielder (1982) elucidated their genesis through a variety of flume/wind tunnel experiments, and also noted their occurrence in ancient eolian deposits. In fact, the same quarries that produce the jellyfish impressions in the Cambrian of Wisconsin ALSO produce some pretty nice examples of adhesion ripples. These are actually pretty handy structures, and have been used as evidence for a subaerial phase in some of these enigmatic mid-continent sandstones everyone seems to fond of.

Anyway, a little known but potentially quite helpful sedimentary structure to keep in mind when out looking at the rocks!

Crab Pavement!

2012-01-13T06:39:00.000-08:00

Day three of our "dead beach stuff" marathon here at the ol' Blog; you can catch up on all the grim action on these previous posts. Anyway, today's litore mortem comes again from the Jersey coastline at Sandy Hook. It was a blustery day, with 40 mph gusts along the shoreline, and very very very cold. Anyway, the wind was SO strong, it was pretty actively entraining some sand, leaving behind only the largest clasts, including...a whole bunch of dead crabs!

These crabs were littered everywhere, and the aeolian evacuation of sand was leaving behind the crustaceans to form a nifty little crab-enriched interval.

Gruesome, ain't it!?!

Sometimes, the crabs were serving as baffles to the blowing sand, like this little guy below:

Nifty!

More Dead Things on the Beach!

2012-01-12T09:02:00.000-08:00

Continuing the trend from yesterday, here's another picture of some dead stuff I found on the beach over the holiday break! We've moved out of the Gulf and onto the Atlantic coast, and a far bit more northward as well; these pictures are from Sandy Hook, off the coastline of New Jersey. It's a ray, washed WAAAAAAAY the hell up on the backshore during a pretty tremendous storm that hit the Atlantic coast.

And here's the poor critter, flipped over.

Jellyfish on the Beach

2012-01-11T13:02:00.000-08:00

The shoreline is always a fun place to visit; not only is it a picturesque confluence of all sorts of sedimentary and geomorphic processes mingling and interacting with on another, but there's all sorts of wiggy critters and nifty biology to see as well. Over the break, I had the chance to spend a lovely day at the beach on St. George's island, a barrier island in the Gulf of Mexico not too far from the Oyster Capital of the Gulf, Apalachicola Florida. Some recent storms had stirred up the shoreface a bit, resulting in some pretty nifty shell hashes and fragments scattered all over. However, along with the biomineralized detritus cast up by storm waves, there were also a fair number of these guys:

Jellys! Subaerially exposed! Some of these, like the one in the picture above, were exposed in the littoral zone, but a few of comparable size had been chucked up pretty far onto the beach, out of range of fairweather wave activity. Always fun to see cnidarians, especially when the chance of getting stung in minimal. Anyway, seeing all these jellys, deposited on well-sorted, upper fine- to medium- grained sand got me thinking about a taphonomy...after all, Jellys aren't called Jellys out of some wry sense of irony. These soft, squishy, blobby little guys, chucked up into high-energy settings like the foreshore, don't have much of a chance at preservation, especially with a bunch of other critters rambling about over the beach. However, such was not always the case!

A similar occurrence of cnidarians and high-energy deposits has been documented from the Cambrian, with some very nice examples coming out of the midcontinent region in particular. Hagadorn et al. (2002) documented a pretty awesome occurrence from the "middle" Cambrian Mt. Simon/Wonewoc sandstones. Below is their Figure 3, from page 149.

Pretty cool! It's a little more densely packed with the tragically stranded cnidarians, and the sedimentary structures are different, but all in all, it's pretty much a Cambrian example of my day at the beach!

Hagadorn et al. (2002) noted that, as discussed above, the taphonomy of jelly preservation requires some sort of explanation. First off, these deposits don't show any evidence for rapid burial, one of the more commonly evoked explanations for exceptional fossil preservation. Rather, these jellyfish show themselves, on the basis of both sedimentary structures and the overall stratigraphic succession, to have been deposited in a fairly active shoreface/foreshore paleoenvironment. Additionally, there's no evidence in these rocks for microbial structures or features, meaning that we can't evoke a "gooey substrate" explanation, either. So, how did these guys get into the rock record!?

An important hint, recognized by Hagadorn et al. (2002), can be found in the explanation of why washed up jelly's DON'T get preserved today...namely, lots of scavenging terrestrial critters and especially lots of deep digging bioturbators. One of the ways the weird world of the Cambrian differs from ours today is the fact that the organisms that do those things hadn't evolved yet, meaning that, for a brief window of time, these sort of "stranding" deposits of organisms are actually pretty darn likely to enter the stratigraphic record.

Just goes to show you that, in addition to our uniformitarian world view, we also have to keep in mind the arrow of secular variation, and how dynamic and complex the interaction is between critters and their environments.

WORKS CITED

Hagadorn, J.W., Dott, R.H., Jr., and Damrow, D., 2002, Stranded on a Late Cambrian shoreline: Medusae from central Wisconsin: Geology, v. 30, p. 147-150

Steno on Google!

2012-01-11T05:43:00.000-08:00

Jumpin' Cats! Take a look at today's Google Doodle thingy...it's Nick Steno's 374th B-Day, and they've got a cartoon in honor of it! Neat-o!

Steno has, of course, been mythologized as one of the fabled "father's o' geology", most often remembered for his "three Laws": Original Horizontality, Lateral Continuity, and of course Superposition. Pretty nice exposure!

EDIT: I guess it is a bit layer-cakey...maybe for Wheeler's Birthday, they'll have an animated one that blows it apart and constructs a Wheeler Diagram, to show the difference between time-as-rock and time-as-surfaces.

Desert Horned Lizard!

2012-01-10T08:05:00.000-08:00

A quick picture of some more neat-o herpetofauna! This one is a desert horned lizard, from the Valley of Fire State Park in Nevada.

Pretty slick camo, eh?

Privilege, Equality, and Disparity: A Link To A Totally Rad Essay

2011-12-12T15:17:00.000-08:00

I just wanted to quickly point out a really excellent essay that does a killer job deconstructing and exploring the (sometimes stealthy) role that "privilege" has in creating disparities between folks. The essay, titled "Sacrificing Privilege" and hosted at Skepchick, is a clear and well-written exploration of how a "privileged" status, defined on the basis of race, gender, or what-have-you, can serve as the basis of a pervasive and potentially "invisible" culture of bias.

This is an extremely important message that we in the sciences (and especially the Earth Sciences) NEED to understand if we ever want to get away from the "(White) Boys' Club" that defines so many fields. As discussed here in a previous post, Geology has a real problem with regards to gender; understanding and working to eliminate the (often hidden) cultural biases that make it hard for women and minorities to find a home in the sciences is the only way that we'll ever get better. So everyone read the essay linked above! It's long, but well worth the time!

Evaporite Casts in Sandstone

2011-12-06T07:32:00.001-08:00

I've been working, as part of the ol' PhD rigamarole, in the Wilkins Peak Member, which is part of the Eocene Green River Formation in southwest Wyoming. Anyway, this part of the world during the Eocene was characterized by extremely high evaporation coupled with relatively low precipitation, which is a perfect setting for the formation of evaporites! High evaporation rates drive off water, while leaving behind water soluable ions, resulting over time in highly concentrated brines from which evaporite minerals form.

In previous posts, I've shown some modern examples of evaporite formation from Death Valley, where evaporites are precipitating on a playa surface, which is a pretty good analogue for parts of the Wilkins Peak. This previous post actually shows some evaporite mineral casts from the purely lacustrine portion of the Wilkins Peak, probably some sort of Na-rich evaporite.

However, you don't have to be in the lake for evaporites to form! These pictures below are evaporite mineral casts preserved in sandstones that formed as part of the floodplain/overbank setting of a fluvial system that fed into the lake.

Here's a closer view, showing the bladed, fairly delicate looking crystalline features of the evaporites, preserved in the sands.

I reckon these are Nahcolite casts, on account of their elongated crystal habit, but then again I'm no evaporite specialist. Still, they're kind of nifty!

Ophiomorpha in core

2011-12-02T07:38:00.001-08:00

Trace fossils are, as I've said before, pretty rad. As a sed/strat type, I mostly appreciate them for their utility in paleoenvironmental reconstructions, their ability to help us constrain substrate conditions, and the help they can give us in interrogating rates and processes of sedimentation. And, of course, there's all sorts of biological and ecological info to be gleaned from the paleoichnological record as well.

Trace fossils are particularly valuable when all you've got is 3 inch-wide cores to work with! I'm mostly a field guy, but sadly, some strata remain inaccessibly trapped below the surface of the earth, removed from the joyous and perfect cycle of erosion and redeposition that is the true destiny of all rocks everywhere. When we want to investigate these strata, we're forced to yank a plug of rock out of a well somewhere, and just hope for the best. It's not ideal, but you gotta work with what you've got...

Anyway, below are a few pictures of some Ophiomorpha traces I found in core from the Paleocene-Eocene Wilcox fluvial/alluvial/deltaic sediments of the Gulf Coast. Ophiomorpha is such a neat little trace fossil; a little shrimpy bastard digs his way into some shifting sediment, and in order to keep his little dwelling tunnel safe from collapse, he rolls his own shit into little balls, and sticks it into the walls of the burrow. Ah, The Grandeur of Nature at Work!

In the picture above, we've got a pretty nice cross-section in a massive, medium-grained sandstone. You can see pretty clearly the nice fecal ball lining surrounding the inner (and, in the animal's lifetime, what would have been hollow) chamber.

Here's a cut along the length of an Ophiomorpha, truncated by an erosion surface and subsequent plow-and-fill sediment, which was itself burrowed into by yet more Ophiomorpha-producin' shrimp.

And, finally, here's an oblique cross-section of another little tube (maybe a bit squashed, as well?). Trace fossils are handy things to have around, especially when all you've got is core!

Burgess Fauna Zapruder Film

2011-12-01T06:14:00.001-08:00

Here's something to start the day off RIGHT! A little movie, from the Royal Ontario Museum, showing a catastrophic mud-rich turbidity current sweeping over some poor Burgess Critters! They've even got the ol' cinematic rumble going on! Poor little Anomalocaris!

Lower Mississippi Valley Geomorph

2011-11-30T12:54:00.001-08:00

Google informs me that it is ol' Mark Twain's 176th Birthday today, so a quick post pointing out some pretty nifty Mississippi River research seems appropriate today. The Army Corps of Engineers has a pretty nice Lower Mississippi Mapping Project webpage that provides access to a classic of the Mississippi River literature: Fisk's 1944 report "Geological Investigation of the Alluvial Valley of the Lower Mississippi River" in pdf form. It's a classic piece of geo-literature, and was the culmination of a pretty exhaustive survey and mapping project carried out in the Lower Miss. River. What's EXTRA rad, of course, is the fact that they've also scanned the completely awesome PLATES that went with the report! Here's a small example below, although the scanned versions are full sized (something like 15 in x 20 in, or so, I reckon):

The plates are color coded for different ages of point bar migration, chute cut-offs, and avulsions, and pretty much succinctly present the whole complicated story of channelbelt evolution in this portion of the lower Mississippi River Valley. It's a pretty cool resource to have access to, and makes for some pretty posters, as well.

And, while I'm sure everyone enjoys some classic Mississippi River Science on Twain's Birthday, I reckon folks oughta' read SOMETHING by ol' Twain...so here's a link to "The War Prayer", which pretty much says it all, really. Enjoy!

Rocks at Dawn!

2011-11-23T14:09:00.001-08:00

Busy busy busy! Just a quick post with some more pretty pictures from out west...let the glow of dawn light on the fluvial/alluvial Cathedral Bluffs keep you warm on these wintery days!

Interbedded sandstones (of both the channelform and sheety variety) are dominantly white, though up-close inspections reveal a fair amount of lithic fragments, including sed rocks and feldspar rich igneous chunks. Reddish, laterally extensive silt-rich mudrocks make up the rest of this succession.

Happy Thanksgiving Eve!

Channelform Picture #3241 - Cathedral Bluffs

2011-11-11T07:46:00.001-08:00

Cold and dreary November days call for cheery remembrances, so I thought I'd share one with you: a spiffy little single-story, lateral-accretion dominated channelform from the Eocene of southwest Wyoming, truncating some mud-rich overbank/floodplain deposits.

Man, I have a LOT of pictures of channelforms...

Frickin' Fracking...

2011-11-04T13:07:00.000-07:00

Our intense and escalating addiction to sweet, sweet hydrocarbons combined with our collective paranoia about dependency on foreign oil (damn you Canada!) has driven some pretty clever advances in the petroleum geosciences. Whether in terms of important scientific concepts (like chronostratigraphic approaches to understanding the rock record, or facies model approaches to understanding paleoenvironmental characteristics) or in terms of applied engineering (i.e., all the different ways we now have to acquire and understand subsurface data sets), the need to exploit more and more of the Earth's hydrocarbons have led us into heady intellectual territory.

Some of the schemes utilized to find and recover hydrocarbons from the subsurface are downright Strangelovian. While THE goofiest has to be the Wagnerian boondoggle of CO2 sequestration, a close second in terms of seeming craziness is fracking. Hydrofracking, or simply "fracking" if you're "hip" and "with-it", is the process by which humans enhance the connectivity of an existing oil or gas field. Briefly, let's say you've got an gas field sitting out in the middle of nowhere. You know there's hydrocarbons in them there interstitial pores, but your wells aren't producing at the rate or capacity that you had hoped. What you do then is what every red-blooded human has done since we knapped our first flint; you IMPROVE on nature! In this case, you pump a slurry of quartz and who-knows-what chemicals under high pressure into the reservoir in question. The high pressure fluids initiate and build-up a series of new fractures, while the quartz grains prop open the newly anthropogenic fractures, allowing your hydrocarbon fluids to flow more freely.

Fracking has been done for quite a while; commercial use of hydrofracture techniques began in 1949, although people were apparently sending water/nitroglycerine mixtures into wells to do the same thing as early as the 1860s. A pretty good historiography of hydrofracking techniques can be found here.

Despite this long-term history, Fracking has been in the news recently, on account of Oil Companies expanding interests in shale gas reservoirs. Shales, of course, are noted for their very poor porosity and permeability; fine-grained muds undergo some pretty impressive compaction in the subsurface, resulting in "tight" rock that really restricts the fluid flow paths. Since the universe is largely ruled by Irony, however, mudrocks and shales are also often extremely rich in organic material. Organics, when subjected to the right conditions, are what we pump out of the ground in the form of oil and gas. So, these mud-rich reservoirs are often very high in organic content, but actually REMOVING the fluids-of-interest from those sopping shales can be tricky! What nature fails to provide, human ingenuity must produce; thus, frack the shit out of some shales, and viola! You've got a productive field where once was only a tight, uneconomical subsurface lithosome.

However, some spoilsports don't seem to be willing to embrace the Inevitable March of Progress, and have voiced some concern regarding hydrofracking. One of the things that seems to have really caught a lot of people's attention is the supposed link between fracking and seismicity. People are worried that, by producing new fracture networks in the subsurface, hydrofracking might be causing earthquakes. The idea of human-induced seismicity is one of those sort of Doomsday type things that freak folks out, and there have been a number of reports and anecdotes from folks in and around fracking sites claiming that there has been a noticable increase is earthquakes. But is there any evidence for such a link?

A company in the UK, Cuadrilla Resources, recently published a report that does, for perhaps the first time, actually seem to support the idea that hydrofracking can be linked to seismic events. The company was in the Bowland Basin in Lancashire, trying to exploit a shale gas play through hydrofracking. Their press release can be found here, while the pertinent (and actually fairly interesting) technical report is available as well, titled "Geotechnical Study of Bowland Basin Seismicity".

Briefly, the company had been monitoring seismic activity during their fracking proceedures, generally through the use of down-hole geophones. In the past, these had recorded seismic events well below the "0" magnitude threshold that were apparently closely associated with active hydrofracking. However, there were some larger events, including a 2.3 Magnitude event and a 1.5 Magnitude event that the company believes are highly likely to have been caused by their fracking. Importantly, neither of these events had any sort of structural effect at the surface, and didn't actually cause any sort of damage.

What is interesting is the fact that the company's study has identified a few contingent geological factors that seem to have been part of the reason for the fracking-induced seismic activity. These include structurally complicated stratigraphies with locally variable dips as well as pre-existing faults in the succession, which interacted in a sort of "perfect storm" with the hydrofracking to induce slip and result in a series of small earthquakes, including the two "big" ones mentioned above (2.3 and 1.5). The companies conclusion is that, yes Virginia, fracking DID (most likely) cause these specific earthquakes, but a) they weren't that big and didn't do any damage to structures or the the surface and b) the seismic activity was a result of fracking AND the presence of pre-existing structure. The company points out that these local conditions imply that fracking induced seismicity can be the result of very specific conditions that have to be met. Regardless, the report advocates continued monitoring in this and other settings, which would allow us to better understand both the mechanisms and processes that produce fracking seismicity, as well as predict those conditions in other fields in the future.

It's a pretty interesting report, and freely available online, which is nice. And while it does show that fracking CAN cause seismicity, for the reasons stated above it also shows that this seismicity is not that big a deal and actually probably really rare. And, to be honest, I never really FELT like there was much danger of fracking being a big deal in terms of causing earthquakes or destroying towns. Still, it's nice to have some actually science on the subject.

Of course, the REAL worry regarding fracking doesn't have anything to with earthquakes, in my opinion. That's just the sort of sexy catastrophe-mongering peddled by the popular press, and, at the risk of sounding conspiratorial, just the sort of low-risk/high-publicity kind of thing big Industrial/Business concerns like people worrying about. As Pynchon wrote in Gravity's Rainbow, "if they can get you asking the wrong questions, they don't have to worry about the answers".

The Earthquake worry is the wrong question to ask about fracking; what should be eliciting some raised eyebrows is the fact that companies are pumping huge volumes of unknown, proprietary fluids into the ground, with the expressed purpose of making it easier for fluids of ALL kinds to move more easily in the subsurface. Don't worry about earthquakes destroying central Pennsylvania; worry about ground water contamination! And not just from the mystery fluids used in fracking. There's all sorts of unpleasant things in the brines that lurk in the subsurface. I'd like to see a little more transperancy, and a LOT more science, on the question of what impacts, if any, fracking is actually having on groundwater and the environment.

And, as pointed out by the Cuadrilla report, it's often a question of local contingencies that matter. What might be perfectly safe in upstate New York COULD be disastrous in North Dakota, or in Wyoming, or in Romania. The question of fracking needs some serious study, particularly in light of the complicated natural systems that we geologists know characterize the actual Earth.

Armored Mudballs!

2011-10-28T09:02:00.000-07:00

"Quiet water conditions" is the depositional mechanism most often evoked to explain the presence of fine-grained mud in the rock record. Mud, generally made up of clay minerals, is defined on the Udden-Wentworth grain size scale as particles smaller than ~0.00015 inches, or around 0.003 mm. That's pretty small, and any amount of turbulence or motion in a water column will keep particles of that size suspended for quite a while. However, as I've discussed before, there are some hints that a fair portion of mudrock in the stratigraphic record records higher energy conditions; one of the nifty qualities of clay minerals is that they're weakly charged, and can aggregate together into larger "chunks" that behave as hydrodynamically heavier clasts. Sometimes, the features that would record this sort of aggregate/flocculate behavior of mudclasts is subtle or cryptic, especially once muddy sediment gets compacted and flattened out. Sometimes, however, the evidence for muddy clasts is obvious!

The picture below is from the Eocene Cathedral Bluffs Member in SW Wyoming/NW Colorado, a pretty thick succession of fluvial/alluvial sediments that form some fairly picturesque vistas in that area. The channelform sandstones around here are pretty coarse - usually upper Medium at the small end, and sometimes even getting into coarse and very coarse sands (we're pretty near their source area!). Anyway, in among the fluvial sandstones, are things like this:

That's a gravel-sized clast, maybe 50 mm across or so, made up entirely of clay, and coated on the outside by a nice armor of sandy grains glommed onto the outside! In a moment of refreshing clarity, the official science word for these things is the surprisingly restrained term "armored mudball". Nifty, huh? Here's another shot:

You can see that these muddy clasts are floating in a coarse sandy matrix. Because these mudballs are so large, they form a nice erosional lag at the base of the channels.

Here's a close up of some of the gravel-sized mudballs:

The shot below shows the muddy interior of these little fellows:

Neat, huh? Like almost all things in sedimentary geology, mud is a lot more fun once it starts gettin' pushed around by turbulence!

#Occupy Earth

2011-10-25T12:55:00.000-07:00

Man, if you aren't reading Matt Taibbi, then you need to get with the program! He's a writer for Rolling Stone, sometimes on the Olbermann show, and he's just about my favorite writer/journalist/truth-speaker out there. Taibbi hit it out of the park this week, though, with a completely insightful, totally cogent, takes-no-prisoners explanation of the Occupy Wall Street movement. READ IT NOW. It's great, and is the best thing you could give to some of the vote-against-their-own-interest dumbasses out there chortling over all the dirty hippies on the TeeVee. It's a long piece, but well worth the few minutes it takes to read it. Then, afterwards, we can get back to the good ol' Class Warfare! Eat the Rich!

Red Rocks of the Cathedral Bluffs Member

2011-10-17T12:51:00.000-07:00

Just a quick post, to get my bloggin' legs back after fall field work/GSA madness! Here's photographic PROOF that not all red rocks in Wyoming are from the triassic; these are from the Eocene strata of the alluvial/fluvial Cathedral Bluffs, in SW Wyoming. Behold!

Take a look at the variably expressed soil forming processes preserved in the stratigraphic record, as well as the subtle channelform! Nifty, huh!?!

Whale-Fall Puppet Theater

2011-10-15T14:39:00.000-07:00

Radiolab, a completely slick science-and-culture type of show on NPR, recently discussed a Whale Fall in one of their episodes. Whale carcasses represent pretty rich food sources in the oceans, and whole communities of organisms spring up when some poor cetacean kicks the bucket and drifts down to the seafloor. Anyway, a former intern of the show apparently was able to wrangle some very talented folks into making a completely awesome video illustrating the whale fall! The best part - it's all done using paper cut-outs! Cute little paper polychaetes, munching on a dead whale! What more can you ask for! Anyway, here's the video, yanked from the radiolab site:

Whale Fall (after life of a whale) from Sharon Shattuck on Vimeo.

Fall Fieldwork

2011-09-23T07:11:00.000-07:00

Headin' out for a couple of weeks of field work out west, and then to GSA immediately after. Ah, the life of the jet-set!

Anyway, in honor of the field and the west, BEHOLD: The Cretaceous Countyline Channelform!

Click on it to make it bigger, and bask in the architectural glory of the thing!

See ya'll at GSA!

Inoceramid Bivalves in the WIKS

2011-09-09T09:52:00.000-07:00

The Western Interior Cretaceous Seaway (or "WIKS" as all the cool kids call it, which is a way better acronym than the stupid sounding KWIS that I sometimes see...) was pretty darn weird, when you get right down to it. First of all, we've got us a huge seaway that, by the Late Cretaceous, connected the boreal arctic waters of the north to equatorial waters in the Cretaceous equivalent of the Gulf o' Mexico. The seaway followed the general trend of a big ol' foreland basin, a zone of subsidence adjacent to the Sevier fold-and-thrust belt. At it's greatest extent, the seaway's western shoreline ran south from Alaska, through western Alberta, Montana, Wyoming, Utah, and and down into Mexico, while it's eastern shorelines were ~ 1000 km away. North America was a pretty different place in the Cretaceous!

Because this seaway was on continental crust, it wasn't very deep. I've seen depth estimates as high as 700 m or so, but to be honest, I find that a little hard to swallow. On the basis of the geodynamics of thrust emplacement and the subduction response of the foreland basin, as well as some work that's been done on benthic foram assemblages, I think the evidence seems to point towards a shallower, 200-300 m depth range or so.

Regardless, you can imagine that the environment of the WIKS must have been pretty unusual. A long, shallow trough of seawater, connecting to very different portions of the open ocean. And remember, pCO2 estimates and minimal (i.e., no) evidence for high latitude glaciations suggests elevated temperatures in the Cretaceous. Shallow waters and high evaporation rates means that you've got an opportunity to develop some really salty, briny, and generally unpleasant water in the Western Interior. Interestingly, elevated global temperatures might result in considerably less thermal gradients between equatorial and polar water masses, meaning that Cretaceous oceans might have been considerably less thermally stratified. As an aside, it's largely thermally-driven density differences in water masses today that drive the large-scale conveyor belts of ocean currents, which is why anthropogenic climate change has a real potential for screwing up ocean circulation. In the Cretaceous, salinity-driven differences in ocean water density might have had a more profound role in driven oceanic circulation. For this reason, big huge inland seaways, like WIKS, might have been important sources of hot, briny water for driving halothermal circulation.

Of course, we have evidence for unpleasant WIKS environments from more than just paleoceanographic thought experiments. One of the most striking characteristics of WIKS sediments is the fact that the muddy portions of the basin are chock full o' carbon. These black shales can have some shockingly high TOC (Total Organic Carbon), and must have formed under conditions of VERY restricted oxygen availability, anything from complete anoxia all the way up to more gentle dysoxic conditions. In fact, some of these black shale intervals are so striking, and so laterally persistent, that they've been given names: Ocean Anoxic Events, or OAEs in the acronym-rich jargon of geology.

So, in general, we know that a lot of the Western Interior seaway was kind of a rough place to make a living. The impact of this salty, oxygen-starved seaway on biological communities within the seaway is seen in the sort of things that lived and died there. For one thing, ammonoids, those opalescent shelled cephalopods that everyone loves, where all over the western interior seaway. Interestingly, modern examples of shelled cephalopods in the form of Nautilus have exceptionally high tolerance for low-oxygen conditions. Apparently, modern nautiloids will flee predators by going into low-oxygen waters, closing up there shell to conserve oxygen. Predatory fish, who burn oxygen like crazy as part of their active hunting life-style, can't follow a potential Nautilus into those zones. It's a pretty neat trick, and maybe part of the reason why ammonoids were so successful in the WIKS.

But nifty cephalopods weren't the only things living in the seaway. A completely rad group of bivalves, called inoceramids, are present in a lot of the fine-grained, distal portions of the western seaway, where they serve as important biostratigraphic markers. These guys are clams, and the group is characterized by having valves that are both big and flat, with some examples getting to be well over a meter. The picture below is from the Cenomanian of Kansas; the hashy, craggly, flaggy parts (one is juts under the hammer) are inoceramids.

If you look a little closer, you can see the characteristic prismatic texture of the shell; this isn't a diagenetic effect, but rather how the inoceramus precipitated it's carbonate shell. The picture below shows this texture, particularly on the right hand side. Any sed geochem types out there know of any isotopic work done on these shells? Seems like it might be an interesting recorder of bottom water conditions.

Another characteristic thing about these clams is that, in plan view, the shells exhibit marked growth rings. This kind of crappy picture is from the type section of the Cenomanian-Turonian boundary in Colorado; you can see a bit of the ringed morphology of an inoceramid; this poor little guy got himself chewed up as part of a sandy turbidity current. Would that we all could go so nobly into that good night!

The large size of these clams has been explained as being a response to the low oxygen conditions of the WIKS; big clams have bigger gill surface area, and could maybe pull in more oxygen in those rough conditions. They're also some suggestions that these guys might have had chemosynthetic bacteria living symbiotically with them. What is kind of weird is that, for how big the shells are, there wasn't a lot of room for the squishy bits in the middle...in other words, these clams, though impressively massive, would have been disappointing eating, I suspect.

I also wonder how the chemistry of the WIKS water might influenced these guys. We know that there are phases of the Western Interior that are dominated by thick successions of chalk. Maybe these clams dealt with all these ions in solution by precipitating a bunch of CaCO3?

Anyway, they're pretty nifty fellows, and very characteristic of the fine-grained portions of the WIKS. Just goes to show you that, even in the most monotonous-seeming mudrocks, you can still find cool stories about the evolving earth!

I've got some Macrobugs too!

2011-09-07T11:05:00.000-07:00

A few days back, Callan posted some really awesome pictures of some of his local arthopods. I thought I'd share some crawlies as well, although mine aren't local. These are pictures from a muggy mountain hike on Taboga, an island on the pacific side of Panama.

I didn't put any scale bar on this one, but this damn caterpillar was around seven inches long, and started waggling it's head around when we got close to get a picture.

This was a pissed off tarantula, who was busy hunting, and didn't want his picture taken. About as big as my hand (my hands are 38 inches across).

Tea-Party Quote-Matching Madness!

2011-09-02T16:25:00.000-07:00

Just a quick link to something equal parts fun and terrifying! The Iowa Democrats have put together a little matching game using the big Tea-Party nutjobs and some of their more amazing and profound quotes called, simply enough "Guess that Tea Partier!" You should check it out, though don't feel too bad if you miss a bunch...all the crazy sort of blends together, and it can be hard to figure out which particular crazy person said what particular crazy thing. Wonkette suggests making a drinking game out of it...proceed at your own risk.

Hoodoo Tafoni!

2011-09-02T06:30:00.000-07:00

Geology, for all it's complex nomenclature and technical terminology, DOES have some fun words. And, sometimes, you get the chance to combine a couple of fun words together! Behold: HOODOO TAFONI from the Book Cliffs, UT!

Hoodoos are pinnacles of rock caused by caps of resistant lithology that shield underlying sediments from erosion. They tend to look a little rude, and are also (ridiculously) called "fairy chimneys" and "earth pyramids". Tafoni has already been discussed, both at this blog and others. These are erosional features in sandstones that look a little like a bunch of little pits, caused probably by differential weathering.

Hoodoo Tafoni would also make a pretty good band name, when you think about it.

Drilling for Oil...in the Everglades?

2011-08-31T14:02:00.000-07:00

The insane Republican mantra of "DRILL EVERYWHERE!" has been one-up'd recently by everyone's favorite fugue-state maniac, Michelle Bachmann! Whereas the previous crop of knuckle-heads had merely ignored environmental or economic reasons for not tearing the Earth asunder, ol' Bachmann has gone the final step, and is completely ignoring REALITY in here fervent rush to drill the hell out of the US (for Jesus). Her latest scheme for Energy Independence? Drill the Everglades.

Now, most folks would hear about that plan, and decide that, EVEN if there was oil lurking below the peaty vastness of Everglades National Park, perhaps completely destroying one of the most delicate ecosystem in the continental US might not be such a good idea. Hell, the everglades are already stressed by horrendous water issues and terrible invasive organism problems; in the immortal words of the internet, "Leave the Everglades alone!"

But let's say you're some libertarian asshole that doesn't give a piss for the environment. Let's say you couldn't care less about a swath of incredibly beautiful, biologically rich, and ecologically amazing piece of real estate that represents a triumph of the egalitarian spirit of the National Parks System; is there any reason that we SHOULDN'T be drilling in the Everglades for the vast hydrocarbon reserves of southern Florida!?!

Well, one VERY good reason for NOT drilling in the Everglades is that, as it turns out, there ain't any goddamn oil or gas there. And, unless BP has recently initiated an ambitious peat-cutting scheme as a response to their deep water woes, I don't think there's much of a chance of anybody actually wanting to drill into the Everglades any time soon.

Albert Hine, a University of South Florida Geologist, pointed this out to some reporters, who took Hine's observation to Bachmann for comment. Bachmann's response? "The radical environmentalists put up one road block after another to prevent accessing American energy". Intense, huh? AND, despite the fact that she was completely ignorant and wrong about the everglades AND has had it pointed out to her, Bachmann is STILL endorsing a plan to open-up south Florida to oil and gas exploration. That level of madness, pure and blinding as a the sun, is the sort of can-do attitude that the Tea Party brings to America! Facts? Fuck em! We don't need no stinkin' liberal-commie facts!

Sed Structure Sunday - Real Rivers!

2011-08-28T10:45:00.000-07:00

As a continuing service provided by this blog, we'll be using this edition of Sed Structure Sunday to illustrate some of the characteristic features of that strange and mysterious geomorphological entity known as a "RIVER", which apparently has befuddled some folks. Here's a picture of the Green River, Wyoming, showing that most characteristic of river attributes, THE SUBAERIAL CHANNEL, i.e., the big ass declivity through which the water flows.

Note the difference between this sort of water/sediment transport system, and say, tiny adhesive droplets of water flowing at low Reynold's numbers through interstitial pore-space. Pretty much not at all the same thing. Pretty goddamn different beasts all together, when you get right down to it.

Here's a picture of a little bank-attached barform, accreting laterally into the channel. You can also see, to the left of the little point bar, a spot where lower flows cut into the toe of the bar, leaving behind a coarse-grained lag (predominately made up of oil shale weathered off the slopes).

Here's some rad current-ripples on the barform surface, showing flow to the right of the picture (hammer for scale).

And here's a close-up of the same. Neat, huh! Note the muddy drapes present, left behind during the very end of the falling stage of last flow to come through here. Thus are mud rip-ups born!

Backup Amazon (in case the other one breaks?)

2011-08-26T08:19:00.000-07:00

That bastion of careful, insightful science journalism that is The Internet is abuzz with stories of a "second Amazon river" discovered some 4,000 m (!!!) below the Original Recipe Amazon at the surface. The work was done under the auspices of the National Observatory of Brazil, which actually provides a pdf version (in English!) of Pimental and Hamza's talk here. You can find all sorts of third-party stories on a number of "news" websites, apparently because "underground river" is just the kind of evocative bullshit that gets noticed by what passes for science journalists these days. I won't link to them, because they're uniformly stupid.

To summarize their work, Pimental and Hamza report on geothermal data from 241 wells (apparently drilled by Petrobras); 185 of the wells are located in "sedimentary basins", while the remaining wells are located "outside" of those regions, presumably piercing non-sedimentary materials, although that's an assumption I'm making, not one reported in the pdf version of the talk linked above.

The wells monitored what was assumed to be advective heat transfer, which is to say the transfer of heat through the migration of fluids; in this case, deep groundwater moving through permeable rock in the subsurface. Keep in mind, I'm no hydrologist, so I don't know much about the technique of geothermal monitoring and abstracting flow characteristics from that sort of data. There must be, of course, a whole slew of geological factors that influence flow in the subsurface, ranging from sedimentological and stratigraphic attributes all the way to structural geological considerations; however, those data may not be available for the Amazon Basin, or at least weren't reported in Pimental and Hamza (2011).

Importantly, Pimental and Hamza (2011) construct a bunch of 1-D models of heat flow for their individual well sites, and make the assumption that the observed geothermal curves are a result of advective heat transfer. These 1-D thermal profiles are then extrapolated across the basin. Then they divide up there wells into "upper" and "lower" populations (upper and lower in terms of depth), and interpret the different velocities for those different depths as indicating different flow patterns. As reported by Pimental and Hamza (2011), they interpret that there is a lateral west-to-east flow transfer present in the deeper aquifers.

So far, that all seems all right to me; sure, there are problems in extrapolating 1-D data to 3-D basins goes, and maybe there are problems with the assumptions that went into the methods, but that's all fine and good and offers avenues for further investigation. And, of course, the one bright spot in all the reporting has been the idea that these results are preliminary, and that future work will be done to interrogate them further.

The problem, as far as I can see it, comes in when Pimental and Hamza start to compare the surface flows of the Amazon River with their interpretations of subsurface flow, leading the authors to make some kinda big-deal claims about the importance of this groundwater system. They have a graph, on page 23 of the pdf version of their talk, that provides this comparison. I'll wait while you take a look.

I have some problems with their numbers. First of all, I don't exactly understand what the hell they mean when they say "surface drainage". It seems like they are talking about the channelized system alone, since they label one column "Amazon River" but the width value they give is kind of off...the Amazon, at low flows, ranges from 1 to 10 km wide, but when experiencing above bankfull conditions it'll spread out to 50 km or so. Are Pimental and Hamza just sort of averaging the width to somewhere between 1-100 km? Or are they also talking about overland flow in the floodplain drainage? Who knows?

By far, though, the goofiest number is the discharge value given for the Amazon. Look, the paraphrase Douglas Adams, the Amazon River is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. It supplies like 20% of the freshwater to the ocean, for god's sake! But Pimental and Hamza provide a MUCH too small estimate of the Amazon's annual discharge. They state that the flow rate is 133.000 m^3/s, which is either 133 or 133,000 with that weird euro-convention of a period instead of a comma. I'll give them the benefit of the doubt and assume that they don't mean 133, which is silly, but even 133,000 is only half of the actual number. Estimates for discharge range a little closer to 210,000 m^3/s, with an upper value of +300,000 m^3/s during the rainy season. This, in comparison to their groundwater flow estimate of 3900 m^3/s. Orders of magnitude, folks. AND that's assuming that the discharge value for the groundwater stands up to further interrogation.

If you look at the number, however, the overall contribution of the groundwater value reported is ~1-2% of the discharge of the huge ass Amazon River. Yet, for some reason, the National Observatory of Brazil put out a statement that says that this is the "likely" that the low salinity found at the mouth of the Amazon is caused by this groundwater contribution. That is a stupid thing to say, National Observatory of Brazil. The reason the ocean is fresher at the mouth of the Amazon is because the Amazon is a fucking HOSE, dumping an unbelievable amount of freshwater into the sea at an ungodly rate!

Most annoyingly, of course, is the fact that for some inexplicable reason, Pimental and Hamza (2011) refer to this subsurface flow as a "River", even going so far to name it the "Rio Hamza" in honor of one of the authors. And, of course, it's the "underground river" angle that got the newsoids all excited. I honestly can't tell why Pimental and Hamza decided to do that; is it just poetical, or what? Look, people are already stupid enough, and think that the water they get out of a well taps into underground rivers in caves, or huge open water lakes deep in the earth, rather than recognizing the truth about interstitial water between grains. For the love of god, don't confuse them any further by making them think that, 4000 meters below the Amazon River there's a second river, flowing along and full of subterranean Caimans, BECAUSE THAT'S WHAT PEOPLE THINK WHEN THEY HEAR UNDERGROUND RIVER!

To sum up my view on the whole thing: Pimental and Hamza (2011) identify some tantalizing evidence that there might be some lateral mobility in the groundwater deep in the Amazon Basin, and that this water might discharge into the open ocean at the mouth of the river. This was based on a bunch of 1-D well log models of flow velocities extrapolated over the whole area of the basin, and not on any sort of tracer study or more complicated modelling. The amount of water discharged is inferred to be ~1% the value of the Amazon River's discharge, which is nothing to sneeze at, but this is going to need a LOT more data to validate such a conclusion. For some reason, the authors decide to name tiny little blebs of water squishing along through interstitial pores a "River", which is wrong and terribly confusing to people who are already shockingly ignorant about how the earth works.

The whole thing makes me mad, but now when you search "Amazon River" on the Googles, you're going to be faced with a bullshit story about a "second River", without any attempt by any of the "journalists" to point out that, well, you know, water might be moving underground and all, but it sure as shit ain't a river, and it certainly ain't on the goddamn scale of the, you know, ACTUAL RIVER sittin' up there on the surface. My prediction: you will never hear about this work again, because future work is going to DRASTICALLY reduce the actual discharge estimates from the groundwater.

Ugh.

Apocoloquake? Earth Quakemaggedon? Quakes on a Plain?

2011-08-23T12:14:00.000-07:00

Man, how rad is the USGS? I'm always impressed with how quickly they move when it comes to getting the info out there for earthquakes, and they certainly didn't let us down with regards to the VA earthquake! Anyway, just to head off the inevitable nutjob rapture-ready end-o-the-world types, I thought I'd post the USGS's 2008 Earthquake hazard map. See, VA has a higher hazard rating than most of the east coast! Nothin' supernatural or eschatological about it. Who knew!?! (Answer: the USGS).

Equally rad is the chance for some good ol' fashioned citizen science at the "Did You Feel It" site, where you can help the USGS build a picture of the effects of earthquakes by adding your own report. Do so NOW, before future Co-Presidents for Life Bachmann and Perry shut down the communistic hive of nanny-state socialism that is government funded science!

Sole-Saving Sed Structure Sunday!

2011-08-21T12:40:00.000-07:00

Brian shared an image of some completely rad flute marks on Friday, which has inspired me to dedicate this Sunday Sed Structure to saving some SOLES! Sole marks, that is! As Brian pointed out, sole marks are a whole suite of erosional features generally preserved on the lower boundaries of beds. Sole mark taxonomy can get complicated, because the features are caused by a range of subtle processes that grade into each other; however, you can safely subdivide sole marks into those produced by fluid scour versus those produced by tools or objects interacting with the substrate. Below is a quicky flowchart I made for a sed class I TA'd in the past, describing some of the salient features of the different "kinds" of sole marks.

Sole marks are pretty cool; they're some fairly solid paleocurrent indicators, even when they only give you a trend of motion without a sense of direction. More important than that, however, is the fact that, at least for the scours like flutes marks and gutter casts, these sole marks actually represent pretty dramatically high energy conditions, much higher than for any measly ol' cross-stratification your going to find. That ability to start subdividing energy states in a stratigraphic section is key, and sole marks are incredibly useful when interrogating strata at fine scales of resolution.

Anyway, the picture below is from some Wilkins Peak Ss (Eocene, Green River Formation), showing a sole mark on the base of a channelform. This is an example of a groove cast, meaning that a big ol' chunk of something (probably some wood) scrapped along the base of this channel. At some point later, river sediments filled in the erosion gouge, casting the feature we see below. Importantly, these features that record erosion, exposure, and high energy are often found in association with things like lag deposits.

This picture below shows some smaller groove casts in a parallel grouping, from the same succession of rocks.

Show some love for some erosional features, and they'll love you back, I promise.

"Cognitive Sewage", Public Policy, and Communicating Science

2011-08-20T12:49:00.000-07:00

A perennial lament heard on the science-scene: "why is The Public so damn irrational!". The frustration of having perfectly sound science ignored or rejected out of hand by Folks must account for more than a few gray hairs (although it's probably good for beer sales). We're all pretty familiar with irrationality born of wacko-idealogies, like creationists, climate change deniers, or expanding earthers; from the stand point of Science, there's not really much you can do about those deeply rooted irrationalities that motive people like that.

The earth sciences (broadly defined) have a lot of interaction with the irrational public, largely because we deal with complex systems that have a definite effect of peoples' lives. It's hard to get worked up about quarks (beyond the "gee-whiz" factor, I suppose), whereas acid mine drainage, or peak oil, or ocean acidification have a very concrete ability to impact people and the environment. How do we engage people about these complex issues?

There's a really interesting story up from NPR, which previously aired on Morning Edition a week or so ago, titled "Why Cleaned Wastewater Stay Dirty In Our Minds". Briefly, some clever engineers down in California have been looking for solutions to the region's horrible water situation, and they came to a very reasonable, rational, and environmentally sound conclusion: recycle sewage water into potable drinking water for communities. Pretty good idea, huh?

BUT, when they tried to implement the plan, the public balked. Rather than gnashing his teeth, a UC-Santa Cruz Environmental Studies prof decided to tackle the question of WHY people reacted so negatively to such an eminently reasonable idea. And the way he attacked the problem was through psychology. What they found when they talked to people was that people was that, as in a lot of human experience, people were engaging in what is called "contagion thinking". A pretty clear example of this is given by a psychologist who participated in the study: if asked to value a family heirloom versus an EXACT replica of the heirloom, people pick the original, since it has a history (through contact) that makes it MORE valuable, even if two objects are identical physically.

This sort of thinking carries over into how people think about resources; if their water has ever been in contact with sewage, it's contaminated irrevocably, which gives rise to the completely rad phrase used in the study of "conceptual sewage". Even more interesting was what the study found in regards to people's view on preferred water resources. Given the choice, people would rather have water from a river or aquifer than from treated sewage, despite the fact that water in rivers or aquifers has, through a matter of course, at some point been in contact with something's digestive/excretory system. Unless we start synthesizing water directly from volcanic gases, or from the atomic furnaces of stars, you aren't going to be free of the historical fact that, at some point, someone or something pissed in your water supply. So why doesn't that bother people?

The question sort of get's at peoples' conceptualization of what is "natural" or "clean", and seems to hinge on the idea that, through the natural processes that feed rivers or supply aquifers, some sort of conceptual transformation in applied to the water that makes it "clean". In the article, it's suggested that, by introducing some sort of "naturalizing" aspect to the sewage treatment might make it more palatable (both figuratively and literally) for people. This despite the fact that, as noted in the story, pumping treated water back out into the environment is, objectively, going to degrade it's quality.

It's a really interesting article, and one that we as Earth Scientists should really be paying attention to. What we do and how our science is used impacts peoples lives, and we need to be aware that is in and of itself a transformative process. Science as an adviser to policy has to take into account the history, psychology, sociology, and cultural milieu that it's trying to influence, and that's something that we science-types just don't seem to think about all that often. Take the water issue discussed in the NPR story. One approach could have been to have just said, "too bad, we need to conserve water so we're going to recycle sewage". What response might that engender in the public? Maybe they start buying only bottled water, exacerbating water supply issues and producing mountains of plastic garbage. And poorer people might not be able to afford exclusivity bottled water, exacerbating class division and economic disparities. OR poorer people might decide that, since the water from the faucet is (cognitive) shit, they're just going to have to spend more of their money on only buying bottled water, stretching their fragile finances even further.

It's a complicated issue, and one that we really aught to be thinking about every day, and in a variety of situations. And the earth sciences are right at the heart of all these complex intersections between natural systems, people, society, economics...all that stuff that makes up the complicated mess we call the real world. The NPR report does a pretty good job introducing the topic, and the link above let's to listen to the audio version of the report that played on Morning Edition. Enjoy!

Nifty phytoplankton bloom image

2011-08-18T07:32:00.000-07:00

An awesome image of a huge plankton bloom in the Barents Sea, courtesy of the MODIS from the Aqua Satellite, taken on Aug 14. The Barents is at its freshest and most nutrient depleted during this time, due to glacial melt, which creates ideal conditions for a big ol' bloom of these tiny little organisms. Apparently, the milky blue colors are inferred to be the result of a bunch of coccolithophores, tiny photosynthetic bugs that make a produce calcite tests. Just think; if you were in orbit during the Cretaceous over the eastern end of the Western Interior Seaway (say, Kansas or Nebraska), you might have seen just such an scene! And check out those Helmholtz whirls where the plume is mixing with the ambient water! Rad!

The image, and more information about it, can be found at NASA's Earth Observatory page.

In Hell: Two Years with Tea Party

2011-08-17T12:53:00.000-07:00

Have you heard about these "Tea Partiers"? You might have missed them...they're a pretty quiet lot that prefers to lay low and let their carefully reasoned and well-crafted arguments do their talking for them. When I think of Tea Partiers, I tend to envision some frothy Randian with a tenuous grasp on economics, but this article suggests that the tax/libertarianism aspect of the group is largely flash-in-the-pan opportunism. The real core value of these people, as we all probably already know, is a rabid Christian fundamentalism that promulgates a revisionist version of US history as a means of legitimizing their batshit insanity. I for one am shocked! SHOCKED!

The Embiggening Earth Redux

2011-08-17T06:24:00.000-07:00

A few years back, at the Dawn of this Blog, I posted a little piece about the ridiculously pseudoscientific idea of the "Expanding Earth". Apparently there are crazy people with no understanding of science or rationality who think, for a variety of insane reasons, that Plate Tectonics is yet another example of a Big Science Conspiracy that seeks to bury the truth: namely, that the Earth is getting bigger through time, and that everything we know about geology, chemistry, physics, biology, etc, is all a BIG LIE!!!!!!!! It's pretty weird stuff, and some of the comments on the above linked post were so nutty that folks with peanut allergies shouldn't read them.

Anyway, to the vast corpus of evidence in support of plate tectonics (i.e., predictability/explicative power of sedimentary basins, mountain belts, and a whole lot of tectonic features, apparent polar wander, geophysically observed subducted crust, sea-floor spreading, etc, etc, etc) we can NOW add a DIRECT MEASURE of the changes in the Earth's radius. The rate of change, according to this JPL/NASA study, is ~0.1 mm/year, which is within instrument error and not statistically significant. In other words...the Earth ain't embiggening.

It's a pretty nifty example of detailed geodetic measurements, gravity measurements, and complex data processing that provides a pretty robust direct measure of everything we already knew about the Earth. The paper, which goes into all the nitty-gritty goodness of complicated geo-math, was published in Geophysical Research Letters, and can be found here.

Of course, as we all know, their ain't no gettin' through to the True Believers, and they will no doubt see this as more evidence for the vast science conspiracy that seeks to thwart their brilliance and hid the importance of their unified field theories of everything. Oh well.

Boar's Tusk!

2011-08-12T06:00:00.000-07:00

Following up on yesterday's post and Callan's rad red desert gigapan, I thought I'd share a couple more shots, this time of the Boar's Tusk and a little of the Killpecker dune field. If you ever find yourself along Highway 191, you'll be driving right alongside a pretty phenomenal little bit of the high desert that, in addition to some slick geology, is also full of nice scenery. I'd just caution, however, that if you DO decide to drive on the BLM roads, make sure you've got a vehicle with good clearance and four-wheel drive...it can get a little dicey!

Anyway, a prominent feature in the area is the Boar's Tusk. Just like the more famous Devil's Tower, this pinnacle is a Pleistocene-aged volcanic neck that marks the formerly active volcanic fields of the area. It's about 400 feet tall, and is a favorite nest-building site for hawks in the area.

There's a steep little path up to the saddle, but like all volcanic terrain, a fall here can really hurt, so do be careful.

Here's a view, from the saddle, looking south towards White Mountain (the low plateau to the right).

And here's a view looking north, into Killpecker dunes, which is one of the largest active dune fields in the region. Although it's pretty from a distance, the dunes are infested with 4-wheelers and ATVs and the associated jackassery that goes along with it.

Nothin' TOO spectacular, rock wise, but there's some all-right volcanic stuff to look at, IF that's your thing...

The Boar's Tusk has also lent it's name to a beer available at the Bittercreek Brewpub in Rock Springs, WY.

White Mountain Petroglyphs

2011-08-11T13:26:00.000-07:00

Callan recently put up a pretty slick gigapan of some rocks near and dear to my heart. He's got an awesome shot of the Green River Formation exposed on the flank of White Mountain, which I've talked about before (I work in the fluvial portions of the Wilkins Peak Member of the ol' Green River Fm, which is the most clastic phase of the Green River).

If you ever find yourself in the area, you could do worse than just heading north up Highway 191, and taking some time to explore the BLM roads in the area. There are actually some pretty cool petroglyphs to be found in the fluvial sandstones of the Wasatch Formation (Paleocene/earliest Eocene) that underlies the Green River Fm in the Bridger Sub-basin. I visited a BLM-run spot on the flank of White Mountain that showcases some of the best ones to be found in the area, and I thought I'd share some photos:

The picture below is a close-up of the buffalo(?) in the above shot:

The picture below is a little washed out...but if you embiggen it by clicking, you'll see an elk:

Pretty neat! The Sweetwater County tourism board has some info available on the BLM administered site, including driving directions, here.

Cooper's Hawk

2011-08-10T08:16:00.000-07:00

A prospective buyer expresses interest in a used Ford Explorer:

Wave Ripple Formsets

2011-08-09T06:11:00.000-07:00

The tragedy of ripplemarks; ridiculously common, and by and large completely useless when it comes to halfway decent paleocurrent measures. They're just too damn variable, and too easily influenced by extremely local current conditions to be reliable. Oh well...at least they're pretty!

Brittle synsedimentary deformation!

2011-08-07T14:40:00.000-07:00

Synsedimentary deformation is pretty common; pretty much anywhere you go in the stratigraphic record, regardless of age, sediment type, or environment, there will almost always be some sort of sedimentological chaos present. While structural deformation (i.e., deformation due to tectonic processes after burial) is cool and all, synsedimentary deformation (where the chaos occurs contemporaneously with deposition) is, on a purely objective level, much cooler; just think about a delta front slump, the collapse of a point bar, or the huge deformation related to a mass transport complex! And, while the deformation is itself kinda cool to envision, the potential stratigraphic effects that such local reorganizations can have are even more amazing!

Synsedimentary deformation, like all deformation, comes in two flavors - ductile (i.e., folding) or brittle (i.e., faulting). Ductile deformation is probably the most familar style of sysedimentary chaos-ification, and can range in scale from individual mm-scale laminae slipping and folding all the way to huge fold-and-thrust belts at the toes of submarine fans. However, I get the feeling that brittle deformation is maybe more common in the rock record than is often reported, especially at the smaller end of the scale.

The picture below is from the cretaceous Ferron Ss, at the famous and picturesque Muddy Creek, Utah, and shows some examples of synsedimentary faulting we're talking about. These are in deltaic sediments:

Here's another, from the same section! Nifty, huh?

One more from the Ferron, for good measure!

And, finally, here's syn-sedimentary deformation showing both the faulting AND some subtle "growth-strata" like compensation/adjustment in sedimentation as a result of the deformation, all in one! These are from fluvial strata in the Eocene Green River Formation.

The importance of these brittle processes can't be overestimated, since synsedimentary extensional faulting is an easy way to produce a whole lot of space in a short amount of time. This can produce some dramatic effects, since these little extensional grabbens are ideal sediment ponds. What's especially cool is that you can see synsedimentary deformation directly influencing sedimentation patterns in the rock record (in fact, that's how you distinguish it from the boring ol' structural variety of faulting). You can see how the angle of sedimentation changes as you move up; in otherwords, there's initially some steeply dipping sediments that fill the little pond, with subsequently shallower sedimentation as the wound "heals".

The picture below shows the fault chopping off some sediment below, and juxtaposing more massive sandstones in the hanging wall. Importantly, this deformation is localized, and overlying and underlying sediment don't show any additional deformation - that's how you know it's not related to structural/tectonic deformation, but in fact a process going on at the same time as deposition.

One more, showing the juxtaposition of more massive sands in the hanging wall right against the fault!

Finally, one last picture, showing the (sub-seismic!) outcrop scale deformation possible in some successions. Here, again from the Muddy Creek, are some of the weirdly angled "healing" sediments:

You can imagine how, from a resource perspective, these sorts of things could really complicate your reservoir, and you'd never even know about it!

If you're interested in reading a pretty nifty paper that goes into the palinspastic retrodeformation of these extensional synsedimentary systems in the Ferron, take a look at Bhattacharya and Davies (2004). It's a pretty fun paper that makes a neat study of the linked sedimentology, stratigraphy, and deformation going on in these rocks, AND it's available as a free pdf right here. It's a fun read!

WORKS CITED

Bhattacharya, J.P., and Davies, R.K., 2004, Sedimentology and structure of growth faults at the base of the Ferron Member along Muddy Creek, Utah, In: T.C. Chidsey, R.D. Adams, and T.H. Morris (eds.) The Fluvial-deltaic Ferron Sandstone: Regional-to-Wellbore-scale outcrop analog studies and applications to reservoir modeling, AAPG Studies in Geology 50. P. 279-304.

Teredolites, substrates, and stratigraphy

2011-08-06T13:24:00.000-07:00

Trace fossils are pretty rad in and of themselves, but they become especially awesome when they start telling us all sorts of sedimentologically and stratigraphically interesting stories. Particularly nifty for us soft rock types is the fact that trace fossils quite often record all sorts of neat information about substrate conditions. In terms of paleoenvironmental indicators, subtle variations in the consistency and nature of underlying sediment can have important implications for reconstructing ancient ecology or paleogeomorphology.

Perhaps more importantly, a huge amount of stratigraphic information is often wrapped up in bioturbated surfaces. The most famous example is seen in the Ophiomorpha vs. Thalassanoides dichotomy, where the same critter (a shrimp) produces two very different traces depending on if the sediment was soft and mucky or firm and compacted. This distinction is important stratigraphically, as a compacted substrate reflects erosion and exposure of previously buried sediment. On the basis of trace fossil assemblages, stratigraphers and paleoichnologists have identified a continuum of substrate types, generally ranging from softgrounds (think gloppy mud, or loose, wet sand), firmgrounds, and hardgrounds (think exposed coral reefs). Substrate consistency has all sorts of implications for picking out chronostratigraphically important surfaces.

By far, the bulk of ichnology/seds work has been undertaken in the marine realm. However, heading up the profile into marginal marine and coastal sediments holds some pretty exciting trace-to-rock relationships for us to interrogate. Perhaps niftiest of the traces found in the somewhat-drier-world of coastal rivers is the humble Teredolites.

The wild Teredolites looks like a stubby bulb, with a broad base that tapers up towards a shallow opening. They're commonly sand-filled, though muddy ones are not unheard of, and they often occur in clumps along surfaces. These little club-shaped excavations are dug out by cute little bivalves, colloquially known as "ship-worms" today. The picture below, seized from the USGS, gives you an idea of what they look like:

Because I'm not an oil geologist, I don't own a yacht, so my exposure to these little fellows is limited only to the stratigraphic record. And perhaps somewhat surprisingly, these guys are actually pretty damn common! In fact, some horizons are pretty much taken over by Teredolites, indicative of a considerable amount of woody (or, to use the fancy science word, xylic) substrates. Bromley et al. (1984) recognized that this was a fundamentally different condition from the traditional soft-firm-hardground spectrum, and helpfully named these "woodgrounds". Furthermore, Bromley et al. (1984) characterize the Teredolites ichnofacies as a suite of traces that uniquely identifies the occurrences of woodgrounds in the rock record. Importantly, a Teredolites-bored log that happened to get washed out onto a submarine fan is NOT an example of the Teredolites ichnofacies; you need to have a lot of Teredolites, in association with a substantial and in situ woody substrate to qualify.

How is a woodground different from the other "grounds" and, perhaps more importantly, who the hell cares? Well, for one thing, the presence of woody substrates is pretty distinct environmentally as well as ecologically. Natural accumulations of woody material are unique types of environments, and take on a special meaning in the stratigraphic record, where they're known as "coal". In order to get coal in the stratigraphic record, you have to have minimal clastic input, otherwise you just end up with a pile of sand (for instance) with disseminated bits of plant debris scattered throughout. In other words, coal can be diluted to nothing by the addition of a bunch of sediment.

Teredolites is commonly associated with coal deposits in the rock record. The picture below is from the Cretaceous Mesa Verde of Utah, and shows some classic little teredos in association with coal underneath (bumpy bits in the sand, above the hammer; the coal is the black stuff). The trace, then, was bored into the woody stuff beneath, then infilled with sand from a high sinuosity coastal river. So, these traces record the existence of a major coal accumulating swamp...

...of coarse, the presence of all that COAL tells you that too, right? So what's the big deal?

Well, Teredolites is also sometimes found within sediments, often in channeform deposits of ancient rivers, without any associated thick accumulations of coal. Sometimes there will be little chunks of coaly/woody material associated with the teredo traces, and sometimes these clasts can be quite common in the bases of channels. But, there's no big prominent beds of coal to be found anywhere! The picture below, also from the K of Utah, shows just this relationship, with teredo traces and wood/coal fragments within fluvial sandstones.

These Teredo and wood debris intraclasts are actually telling us a pretty cool story. We know, from their presence, that at some point, deposits of woody debris accumulated in the ancient landscape, providing homes for a bunch of cute little shipworms. In otherwords, at some point, the paleoenvironment of the setting in the picture above must have been something like the everglades today; lots of plants, lots of life, and importantly, very little clastic sediment moving around the landscape.

BUT, since these Teredolites-bored wood chunks are clasts in a higher energy sedimentary deposit, we know that those idyllic evergladesean must have come to an end when there was a dramatic and fundamental reorganization in the "plumbing" of the sedimentary system. Where there had previously been slow, steady accumulations of plant matter and very little sediment, there eventually came to be a much higher energy system dominated by erosion and reworking.

This is a pretty amazing reversal, if you think about it. We go from a swamp to a coastal river system, and the only evidence for all the time it took to accumulate the coal is found in the wood-debris lag deposits in some ancient rivers. It's a pretty dramatic story of landscape evolution and sediment routing, one that is luckily pointed out to us by some helpful trace fossils and clasts. The stratigraphic record is dominated by these major shifts in sediment accumulation and reworking, and sometimes the only evidence for a completely vanished landscape can be found in some subtle and seemingly insignificant bits and pieces scattered throughout the preserved stratigraphy.

WORKS CITED

Bromley, R.G., Pemberton, S.G., and Rahmani, R.A., 1984, A Cretaceous woodground: the Teredolites ichnofacies: Journal of Paleontology, v. 58, p. 488-498

History of Oil podcasts

2011-08-05T15:51:00.000-07:00

I recently came across another earth science-flavored podcast out there on the interwebs that folks might enjoy: A History of Oil. A strict adherent to truth in advertising, the podcast author/presenter is going through the history of everyone's favorite hydrocarbon in nice, digestible 10-15 minute segments. I've only listened to the first few episodes, but so far, so good! You can subscribe on that there iTunes! Enjoy!

This thing still on?

2011-08-05T14:35:00.000-07:00

Whew! A little over a YEAR since the last post....kinda lame, but you know how it is. Busy busy busy, and all that wearisome nonsense. Anyway, maybe we can get this piece of shit blog back on the road, alright?

At the very least, let's give that poor Cnemidophorus tigris septentrionalis a little break, huh?

Here's a pretty picture of two rainbows, out Wyoming way, that may warm your hearts...

I promise the next post won't take a year to make an appearance!

Book Cliffs Lizard

2010-06-30T11:17:00.000-07:00

Just a quick post, with some nifty pictures of a big ol' lizard I ran across out in Utah recently. It's around 8 inches long or so (with the tail, mind you), and looks like some kind of skink-like little herp. Anybody got any better ID?

Anyway, enjoy:

Joe Barton - STILL a Stupid Bastard

2010-06-18T06:52:00.000-07:00

A little over a year ago, the distinguished gentlemen from Texas, Joe Barton, proved himself an ass with an attempt to use the presence of oil in Alaska to prove that the Earth had been warmer IPSO FACTO Global Climate Change is a filthy commie lie. And we all had a good laugh, because he's an idiot.

Well, ol' Joe has stepped up to the plate with yet another complete asshole move: he apologized to BP for the government "shake-down" related to the colossal environmental Apocalypse proceeding down Gulf-a-ways. Because, of course, holding companies responsible for their disastrous mistakes and expecting them to behave in a responsible manner is simply un-American. Pretty awesome, Joe! Here's a short clip of the current favorite for "oily sycophant of the year award":

And hell, when even John Boehner thinks that you maybe stepped over the line a little, then man, you've really screwed the pooch!

The Little Grand Canyon of the San Rafael Swell

2010-06-16T08:29:00.000-07:00

I recently spent around 2 weeks bopping around the west, and in particular looking at the completely rad geology to be seen in Utah, Our Nation's Prettiest State. Anyway, one of the places I camped at was a BLM campground south of Price, UT, called "The Wedge". The Wedge sits right in the heart of the San Rafael Swell. Anyway, at this spot, the San Rafael river has sliced clean through the uplift, exposing a a fair bit of the stratigraphy; the Permian Kaibab Limestone at the base, up through the Chinle/Moenkopi red beds and windblown Wingate Sandstone (Triassic), and finally the aeolian Navajo (Jurassic). It's a pretty spot, and one I'd highly recommend for camping and hiking, if you find yourself in the area. Below are some pictures, taken right from the campground, of this amazing area.

The late spring had apparently seen a fair bit of snow, so it's awfully green out that a way right now!

And here's a little evening light photomosaic to enjoy!

Afghanistan's Mineral "Wealth"

2010-06-15T07:12:00.000-07:00

Apparently, Afghanistan is chock-full o' all sorts of precious metals and valuable mineral resources, at least according to the USGS (and the Pentagon Afghanistan Business development group). A recent story in the New York Times details how the USGS, with the help of some previously unstudied Afghan Geological Survey and Soviet Geological Data documents, have determined that Afghanistan has extensive deposits of lots of different kinds of minerals. These include the mundane, like copper and iron (although it appears that Afghanistan has enough of these to become a major world producer), to the more exotic, like lithium and niobium. In fact, according to the Pentagon, Afghanistan could be the "Saudi Arabia of lithium" (and, as the writers over at the Wonkette pointed out "nothing at all wrong with that sentence", right?).

The figure below was lifted from the New York Times story, and shows the current estimates, in cash money, of the value of all the various types of raw mineral resources estimated to be present in Afghanistan. It's a lot of dollars,for sure!

The science behind the estimates is pretty interesting. In 2004, the USGS started up a project to survey Afghanistan, specifically in terms of water, hydrocarbons, and mineral resources. As part of this, they also spent a fair bit of time pouring over the old Afghan Survey maps and reports (from happier times), as well as the Soviet data. Of course, a lot of these works were 30 years old or so, and hadn't been touched during the bad old days of the Taliban. But, according to the USGS, they were interesting enough to warrant updated surveys, including magnetic and gravity studies over much of the interesting mineralization zones. The USGS has a nifty page, with a lot of summaries, downloadable maps and reports, and history of the project available here. It's neat stuff, and of course, the Geology of Afghanistan is pretty interesting reading.

Although it's great that Afghanistan has something else to possibly develop that could outstrip their current economic model (which, as of right now, is based solely on opium and raw human tragedy), there are some serious concerns, of course. First and foremost, lots of countries in History have had lots of mineral wealth, and it didn't do them to well, did it (Potosi comes to mind)? Afghanistan, ripped to shreds as it is by violence, is ripe for neoimperialist exsanguination, especially if there is a feeling that some countries are "owed" a bit of wealth do to previous investment. The rampant corruption in the Afghan government goes hand in hand with the potential for disaster; apparently, the Afghan Minister of Mines has already been dismissed do to a bribe scandal that involved Chinese copper mining interests.

And, of course, that's another problem on the horizon, too; a return to the "Great Game" of empire building in central Asia seems like a distinct possibility, especially where lots of world powers congregate around raw materials. As the New York Times story points out, China is already making overtures to Afghanistan regarding expanded mining operations.

Finally, what about the environmental and social impacts of opening up mining, willy-nilly, in a dirt poor country ravaged by four decades of war and poverty? Mining is brutal, hard work, even when done right; when it's in a far away place out of public scrutiny, troubles can start (just look at Butte, Montana, or Anaconda, Montana, for examples of home-grown exploitation and environmental/health disasters as a result of poor mining practices).

One hopes that the report of untapped mineral wealth in Afghanistan is good news; it certainly would be a nice economic booster for a country that hasn't had a good decade in a few hundred years. However, the natural pessimist in me can't help but worry about the potential for corruption and further exploitation of a country that has already experienced more than it's fair share of troubles.

Nifty Owl Video

2010-05-23T10:19:00.000-07:00

Nothin' geo-flavored in this post: just a completely kick-ass owl video that I recently stumbled across. The video is from some Japanese TV show, but here's a brief run-down, at least as far as I can tell from the images and different critters being shown.

The owl being shown is (probably) a Common Scops Owl (Otus scops) from South Africa. First thing you'll notice, is that it is cute as hell. However, if you stick with the video a little while, they get to the point of showing that this little guy has some awesome defense/predator avoidance strategies. Here's the video:

When the little Scops owl is confronted with a barn owl (which is just a LITTLE bigger than he is), it really puffs out in an attempt to make itself look huge. But when it's confronted with the much larger and more intimidating Eagle Owl (complete with the Imperial March as it's theme song), it instead elongates itself, producing a much slimmer, narrower profile. According to this info I found at ARKive, it seems like this is a strategy meant to make the Common Scops look more like a twig or branch!

Neat!

Geomorphology From Space!!!

2010-05-17T05:46:00.000-07:00

I recently came across a pretty neat Earth Science resource hidden away on the interwebs here, and I thought I'd share. The Goddard Earth Science Data and Information Service Center's website is, of course, a neat source for a lot of NASA flavored Earth Science info; however, they ALSO have put online a pretty big digital collection of ~270 plates from the out-of-print 1986 book "Geomorphology From Space".

It's got some neat images and interpretive maps for a variety of fairly stunning landforms, although keep in mind this was 1980s-quality pictures...of course, you could probably easily upgrade to better images via Landsat or something.

Anyway, it's pretty neat!

Mangrove Evolution and Plate Tectonics

2010-05-16T08:52:00.001-07:00

More Mangrove madness for May, I guess! Anyway, my previous post about some of the nifty mangroves I'd seen down in the Everglades got me thinkin': what's the evolutionary history of mangroves? Turns out, that's kind of a tricky topic, and one that ends up incorporating a lot of interesting taxonomic, ecological, botanical, and paleobotanical perspectives; as a for-instance, it requires that you make some clear definitions regarding what you mean by "mangrove". In one sense, you can talk about the taxonomic group of fruiting plants that we call "Mangroves" (which includes a lot of ~22 families). HOWEVER, in another sense, we can talk about the ECOLOGICAL niche of "mangroves", i.e., coastal swamps that develop as a result of biologically-mediated factors. A future post will explore those topics in more detail.

THIS post, however, is going to focus on some slick work (in my opinion) that has been done linking mangroves (including genetics AND fossils) with the geological factors that influenced their evolutionary history.

Workers with interests in mangroves have long recognized an interesting pattern in modern mangrove (taxonomically-defined) biogeography, namely that Mangrove species richness declines dramatically from a peak in the West Pacific to a minimum in the Caribbean/West Atlantic Zone. The figure below is from Ellison et al. (1999) that shows this pattern diagrammatically.

There are two explanations that have been put forth to explain this pattern. Originally, mangrove biogeography was explained in the context of an Indonesia/West Pacific "Center of Origin" distribution (Duke, 1995). In otherwords, mangrove taxa originated in one spot, and then subsequently disperesed globally. This is easily the oldest explanation for this observed pattern of diversity, and goes back into the literature for ~100 years.

After the plate tectonic revolution, however, another explanation presented itself: namely, that mangrove taxa evolved around the Tethys seaway in the late Cretaceous, and regional diversity is the result of diversification and evolution in the context of plate tectonics and the movement of continents (Ellison et al., 1999). This has been termed the "vicariance hypothesis", and is the big focus of the paper by Ellison et al. (1999).

Ellison et al. (1999) explore several lines of evidence as a means of testing the validity of one or the other hypotheses, and frankly, I think they're rather clever: FIRST, they take a look at the paleobiogeography of fossil mangroves (pollen or macrofossils) and compare that to modern biogeographic patterns. Ellison et al. (1999) compile a substantial list of fossil mangrove occurrence, and demonstrate that, actually, the fossil record is pretty damn good! The figure below is from Ellison et al. (1999; their figure 2), and shows generalized maps of mangrove occurrence through time.

Importantly, on the basis of their fossil mangrove occurrence database, Ellison et al. (1999) report that, statistically, there isn't any significant correlation between mangrove species-area occurrences and distance from the Indonesian/West Pacific region throughout the Tertiary. What is demonstrated, however, is that mangrove fossil occurrence shows a relativly wide-spread distribution of different mangrove taxa along the ancient Tethyan shoreline. Ellison et al. (1999) recognize that this conclusion provides testable hypotheses for relating other strongly correlated ecological aspects of mangrove environments.

This conclusion leads to their SECOND approach to interrogating mangroves....SNAILS. Turns out, mangroves have some pretty conservative associations with different gastropod taxa; in otherwords, the specific ecology and environmental stresses associated with Mangroves has also resulted in snail populations that almost always co-occur. Cooly, Ellison et al (1999) compile a fossil-occurrence database of gastropods, and compare that distribution to their fossil mangrove database! Neat, huh? Their results are shown below, in their Figure 3:

They proceed to explore ecological "nestedness" of gastropods and mangroves through time, and do some pretty nifty statistical manipulations of the data to test whether mangroves, their gastropods, and the species-area relationships can be associated with a "center-of-origin". Ellison et al. (1999) conclude that, on the basis of the fossil distributions of both mangroves, gastropods, and the patterns of their species-area relationships, that a probable Tethyan origin, and then subsequent diversification patterns are related to tectonic reconfiguration of shorelines and continents. Neat, huh!

It's a pretty neat use of both modern biogeographic patterns as well as ancient data, and it makes me wonder what other possible insights could be mined from both this and other settings? For instance, is there anything we could learn about large-scale paleo-oceanographic circulation patterns from these paleobotanical collections? Can we see other ecosystems being strongly influenced by tectonics in this way? Can we take the fossil record of mangroves, tie it to associated mangrove-dominated depositional environments, and see any statistical patterns in stratigraphic occurrence, mangrove biogeography, and tethyan tectonics? Or how expanding out from the "taxonomic" mangroves into the "ecologic" mangroves, which have a (potentially) older fossil record? Are there any statistical patterns to be elucidated from those occurrences? Who knows!?

Regardless, mangroves are obviously pretty amazing plants, but also seem to have a geological story to tell us as well! Maybe it's time us rock-o-centric types start really thinking about some of the critter-o-centric fields, and how one can inform the other in new and exciting ways.

WORKS CITED:

Duke, N.C., 1995, Genetic diversity, distributional barriers and rafting continents - more thoughts on the evolution of mangroves: Hydrobiologia, v. 295, p. 167-181.

Ellison, A.M., Farnsworth, E.J., and Merkt, R.E., 1999, Origins of mangrove ecosystems and the mangrove biodiversity anomaly: Global Ecology and Biogeography, v. 8, p. 95-115.

Modern Mangroves

2010-05-03T12:14:00.000-07:00

Just a brief picture-y related post, as I try and rise above the clinging busy-ness of the end-o'-the-semester. I was lucky enough to head down to South Florida over the spring break (in late March), and in addition to eating all sorts of delicious shell fish and exotic fruits (sapote! sapodilla!) I also had the chance to see some pretty rad mangroves swamps!

Mangroves, of course, are the utterly kick-ass salinity-tolerating plants that form impressively dense coastal swamps along tropical shorelines. Because they live in environments that are, traditionally, so hostile to plants, these awesome trees have evolved some pretty slick adaptations. They can excrete excess salt from their roots and leaves, which is pretty awesome, and can similarly limit water loss during low-tide exposures. And, from a sedimentological view point, they are also completely amazing sediment baffles, effective at dissipating incoming wave energy and trapping any entrained sediment. Neat-o!

Anyway, the picture below is from Florida bay, and just shows some isolated red mangroves growing out in the shallows. When we came back and mucked around in the mud after low tide, the WHOLE area was just covered in horseshoe crab traces going everywhere (no pictures, sadly...). In the background on the right, you can JUST make out the distopian hellscape that is Miami.

This next picture is from the Everglades, and shows some more Red Mangroves growing along the edge of the brackish water Coot Bay, and were taken as we canoed around the backwaters. Notice the oysters encrusting the mangrove limbs! Neat!

Here's another oyster and mangrove shot!

And, finally, here's some mangrove pneumatophores exposed along the canal access to Coots Bay.

Pretty amazing plants!

The Importance of Stupidity in Research

2010-03-10T07:17:00.001-08:00

Here's a brief essay by Martin Schwartz, published in the Journal of Cell Science. The title really says it all: The Importance of Stupidity in Scientific Research. There's not much more that I can say, except that I think Dr. Schwartz pretty much hits it right on the head with this one! It's a short, one-page essay about the importance of recognizing the human-ness of science and cultivating and fostering the proper attitude towards uncertainty and the unknown in research. Pretty good stuff, with lots of good advice for both Teachers and Students.

Works Cited:

Schwartz, M.A., 2008, The importance of stupidity in scientific research: Journal of Cell Science, v. 121, p. 1771

Non-Newtonian Pool Party!

2010-03-02T06:13:00.000-08:00

Yet more crazy YouTube videos of weird, geologically relevant stuff! This time...it's non-newtonian fluids!

Newtonian fluids are the sort of everyday, hum-drum fluids we generally interact with (like coffee, or beer). If you exert some force over area on a newtonian fluid, it deforms pretty much instantly in proportion to the force applied to it. Another way of saying this is that newtonian fluids have a constant viscosity.

BUT non-newtonain fluids have a variable viscosity; generally, this viscosity varies nonlinearly as a function of either the amount of shear stress (force over an area) applied OR as a time-dependant function. Examples of non-newtonian fluids include things like ketchup (which gets stuck in the bottle until you shake it; the sudden application of force to the ketchup drastically reduces the viscosity, letting it flow out of the bottle) and whipped cream (which experiences an increase in its viscosity as a function of applied shear stress).

If you are lucky enough to be a geologist, then you actually have more opportunities than most to interact with non-newtonian fluids. Drilling muds and clays, used to lubricate drill bits, are examples of non-newtonian fluids. Even cooler, of course, are things like debris flows, which behave as viscous, non-newtonian fluids.

You can make your own shear-thickening non-newtonian fluid right at home, by mixing ~2 parts corn starch with 1 part water; get it good and gloppy, and you've got a fluid that, when you gently push against it, behaves just like water, but when you smack it hard, it behaves more like plastic. Try it out! It's insanely fun!

And, if you are really ambitious, you can fill up a whole giant tub of the stuff, and run across it, like these nuts did (the whole video is in Spanish, so that's a little tricky; still, it's fun!):

AND, just for more fun: here's a video of some of the "do-it-yourself home-made cornstarch non-newtonian fluid", put on a speaker!

Darwin and Earthquakes, on CNN

2010-03-01T12:50:00.000-08:00

I found an interesting little article on CNN's website today: it's a brief write-up of Darwin's own Chilean earthquake experience in 1835, with some excerpts from The Voyage of the Beagle, including his musings on geology, rates, and processes. The piece is written by a historian of science, John van Wyhe, and reiterates that the Earth, just like Darwin observed and recognized, is a dynamic system.

You can read the article here.

Time-lapse video from underneath a glacier

2010-02-28T13:54:00.001-08:00

How's this for rad:

Pretty slick, huh? It's a clip from some NOVA Special on PBS. Just a neat video to help you make it through the afternoon!

The Saddest Trace Fossil In The World

2010-02-23T07:45:00.001-08:00

Trace fossils are great sedimentological tools; they can tell us a lot about the local energy conditions, instantaneous sedimentation styles, and substrate conditions, and tend to be controlled by traditionally hard-to-figure-out paleoenvironmental proxies like salinity, light, and nutrient availability. So, seds-oriented folks trying to get some really detailed info about depositional environments tend to go crazy over these arcane little scratches, tubes, and trails found in the rock record.

However, if you're one of the paleontologically oriented sorts, then I reckon trace fossils must be really aggravating, form a biological perspective at least. Oh, sure, you can get some morphological detail out of them, and narrow down the sort of critter that made them, but don't you just hate how damn COY those little fossils are about the trace-maker's REAL identity?

In a few lucky cases, though, the sedimentary record has conspired to give us little glimpses of the tracemakers identity. But man! It's just so sad, isn't it:

The picture above is of the Jurassic Horseshoe crab Mesolimulus walchi, from Germany, along with its very own preserved trail (probably of the ichnogenus Kouphichnium, but I might be wrong). I took these pictures at the AMNH a couple of years ago...and it was under weird museum mood-lighting, so it was a little darker than optimal for picture taking.

Anyway, this poor little fellow was just tooling along the anoxic bottom, trying to find some oxygen, I reckon, when he just gave up the ghost. I mean, look at him there, and the end of his trail, forever entombed in sediment!

The pathos!

Darwin - The Rock Opera

2010-02-22T06:12:00.000-08:00

Jumpin' Cats! Check it out: Some Swedish band has put together a rock opera based on Charles Darwin's life and work. AND you can stream it live, off that there internet! The masterpiece is called "Tomorrow, in a Year", and includes tracks titled "Geology", "Epochs", and "Letter to Henslow"...how badass is that!?

Geology and Beer

2010-02-21T07:31:00.000-08:00

Despite what those wine-swilling elitist bastards would have you think, the REAL drink of geologists everywhere is BEER. I have a favorite half-remembered quote from some Victorian mountaineer/geologists who said, to the effect, "Beer never tastes so good as after a hard day of field work". Of course, my apocryphal quote speaks Truth: beer, in the field, after a day of measuring section, or mapping, or tromping up and down hill and valley lugging samples, is something to bring a smile to even the most grizzled of geologists.

Anyway, folks might have seen this before, but it bears repeating. Why Geologists Love Beer is an article from Wired, based around beer-drinking culture and the most recent AGU Meeting in San Fransisco. There's even a little video to watch, but be warned: it'll make you thirsty.

Happy Darwin Day!

2010-02-13T07:40:00.000-08:00

Happy Darwin Day, everybody! Celebrate the day by punching a creationists and (if you can) maybe enjoy a little differential reproductive success, you know what I mean, wink wink wink.

Also, here's a link from The Victorian Web with an online edition of Richard Owen's anonymously written "Critique of Darwin's Origin of the Species"; it's an interesting read, mainly on account of it PRETTY much making all the exact same arguments that stupid creationists make today...they just don't learn!

Oh well! Happy Darwin Day!

Mudball clasts

2010-01-31T08:34:00.000-08:00

Over the holiday break, I had the chance to visit Providence Canyon, GA, sometimes called the "Grand Canyon of Georgia", since it's the biggest hole (other than Zell Miller) in all of the state. Anyway, the canyon is a big ol' erosional feature caused by extremely poor land management in the 1800's; basically, someone irrigation ditches got a "little out of hand", and resulted in a 200 foot canyon that exposes Cretaceous shoreface sandstones. The picture below is a view out into the canyon from the rim.

Anyway, while tromping around in the canyons proper, we came across some features that made me think of my Mud as Sand post from last year. In that post, I discussed some work by Wright and Marriott, a Sedimentary Geology article from 2007 entitled "The dangers of taking mud for granted: lessons from lower Old Red Sandstone dryland river systems of South Wales." In this paper, Wright and Marriott (2007) point out that mud, when glommed together into larger mudballs, can behave hydrodynamically as sand grains. Thus, some of the mud that we so glibly ID as "fine-grained suspension fallout" is actually the result of traction current sedimentation in turbulent flows, and probably has some sort of bed structure, cross-stratification, etc. in it.

In addition to all the sand in Providence Canyon, there is a lot of muddy sediment exposed as well. We had been hiking around after a series of pretty big rainstorms, and I was busy sticking my nose into every rill, cut, and stream channel I came across. Mostly, they conformed to expectations, like the nice-little bit of braid-plain self-similarity evidenced in this erosional feature below:

I also came across some rather larger clasts, hanging out as lags in the bases of the little creeks that drain the main arms of the canyon. Like so:

HOWEVER, upon closer inspection, I found that these clasts were, in fact, entirely made of clay aggregates! In the picture below, you'll appreciate how sticky they are:

So just think about that next time you come across a muddy lens in some channelform sandstone body, eh? Mayhaps it's not finer grains settling out during waining flow, but something even cooler: mud aggregates behaving as sand!

50 Most Loathsome Americans...IT'S FINALLY HERE!

2010-01-29T09:13:00.001-08:00

Man, it's about time. Go forth, and read the words of The Beast.

RIP Howard Zinn

2010-01-28T07:08:00.000-08:00

A bit of sad news today: Historian Howard Zinn, of Boston University, died of a heart attack yesterday. Ol' Zinn wrote the completely kick-ass "A People's History of the United States", was a staunch anti-war activist, and never failed to take the fight to The Man. He was a hero to all the bleeding-heart liberals out there (like me). You can read a good summary of Zinn's life and impact here.

Anyway, to commemorate the man, everyone should go out and kick a Fascist in the balls. And enjoy this interview Zinn did with the Beast, during the dark days of the Bush Presidency.

Another comic!

2009-12-11T08:09:00.000-08:00

Man, I promise, i'm just really busy. It's not like I ONLY sit around lookin' at internet comics all day or anything...just got a lot on my plate, alright? DON'T JUDGE ME!

Anyway, the comic below is from Big Fat Whale, purveyor of transgressive snark since 1324, with a royal charter from King Edward II himself! Enjoy!

Climate Change Deniers are Idiots

2009-12-10T07:16:00.000-08:00

The title pretty much sums up my definitive policy statement on climate change deniers. Emily Flake, of the completely rad LuLu Eightball comic strip, explores the intricacies of various "reasons" for actively denying reality. I snagged it, from the interwebs, and reproduce it for you below. ENJOY!

Pretty accurate, really.

The Return of Sunday Sed Structures!

2009-12-06T08:43:00.000-08:00

A substantial hiatus between "Sunday Sed Structures", perhaps, but seeing as how I'm a fan of the ol' Sed/Strat side of things, I reckon it's perfectly acceptably for me to engage in hiatuses of all sorts (as well as terrible pun-based stratigraphy humor). Below is a picture from the Holiest of Holies, The Book Cliffs!

A pretty big piece of float, perhaps, but it illustrates the elusive and complex 3-Dimensional nature of bedforms rather nicely, I think. On the right-hand face of the boulder, you can see the more traditional trough cross-stratification, oriented roughly parallel to flow. On the left-hand face, you can see the troughs themselves; this view is roughly perpendicular to flow, and preserves the scoop-like trough that is the cross-stratification's namesake. Just goes to show you that when dealing with trough cross-stratification and paleocurrent orientation, you gotta be careful, and TRY to find some nice 3-D (or, more likely, the good ol' 2-and-a-half-D) exposure.

Geophysics and Auto-Tuning

2009-12-01T07:52:00.000-08:00

Despite the common perception that Auto-Tune is an insidious font of evil, born in blackest night by the dreaded Audiomages of Sauron the Great, it can OCCASIONALLY be used to produce some pretty nifty stuff, I GUESS. I'm sure everyone has already encountered the "Symphony of Science" and it's (pretty fun, actually) Auto-tuned Carl Sagan (and others) videos.

But do you know whence Auto-Tune actually sprang? Andy Hildebrand is the name of the inventor, and he worked for Exxon as an engineer, specializing in seimsic data processing. He's also one of the founders of Landmark Graphics, which is all geophysicsy too. Apparently, Dr. Hildebrand recognized that his digital signal processing mojo could also be employed to detect, analyze, and "correct" pitch, undoubtedly saving the careers of many-a-terrible pop singer today (thanks?). Here's the wiki page for Auto-Tune, and here's a Nova Science Now Q&A with Dr. Hildebrand himself.

And it's all thanks to geophysics!

Cyclic subsidence and uplift in the Mississippi Delta

2009-11-30T06:27:00.000-08:00

The Mississippi Delta is really one of those iconic depositional settings within sedimentary geology; when folks talk about deltas, consciously or unconsciously most people get a picture of that big, beautiful, stereotypical Bird's Foot protruding out into the Gulf of Mexico. And not without good cause, of course. From a purely aesthetic viewpoint, the Mississippi Delta is just damn pretty, especially from space, as evidenced by the Earth as Art Landsat image of the Mississippi Delta, below:

And scientifically, the Mississppi Delta has experienced a fair amount of study. Coleman (1988) provided a nice summary of the evolution of the Delta, demonstrating the complexity and extreme variability of the individual delta lobes. The image below is from Coleman (1988, his Figure 2 on p. 1000), and is the iconic illustration of how quickly the individual delta lobes of the Mississippi system switched location:

Coleman (1988) pointed out that the Mississippi system switches the locus of deltaic deposition on average every 1500 years. And keep in mind that each of those lobes covers ~35,000 km2, and is somewhere around 15-25 m thick. That's a lot of sediment in a pretty short amount of time! These pulses of deltaic avulsion and deposition have always been ascribed to the usual suspects in sedimentology: sea-level change, sediment supply changes, and subsidence in the delta.

Interpreting how these forcers interacted with the Mississippi delta system makes up a fair component of the literature, and has provided some interesting insights and entertaining arguments for many years. A recent paper by Blum et al (2008) has revealed a previously unknown driver of change within the deltaic system: cyclic uplift and subsidence driven by changing sediment volumes in the lower Mississippi valley.

Blum et al (2008) point out that the subsidence recorded along the Gulf Coast is different, depending on where you measure it. The figure below is from Blum et al (20088, their Figure 1 on p. 676). Notice how the Alabama and Texas coasts are pretty different from the Valley edge subsidence patterns. Of course, this has been recognized before. Tornqvist et al (2004) interpreted this signal as a result of ongoing glacio-isostaic adjustments. Using marshland peats as baselines, and correcting for the subsidence pattern, Tornqvist et al (2004) reconstructed a sea-level curve for the Mississippi delta.

However, an unexpected result of the Tornqvist model was a phase of "unacceptably high" rate of uplift in the peat benchmarks during the mid-holocene, corresponding to a mid-Holocene sea-level high. Tornqvist et al (2004) did not think that a phase of such large-scale uplift was vary realistic, and discounted it.

However, Blum et al (2008) may have identified a viable mechanism for rapid uplift and subsequent subsidence in the Mississippi Delta. Using the same data points and subsidence curves as Tornqvist et al (2004), Blum et al (2008) preformed a series of 1-D and 3-D isostatic modelling exercises that explain the observed uplift pattern (shown below is their Figure 3, on p. 677).

They interpret a phase of melt-water discharge during the last interglacial as having driven erosion and sediment removal out of the lower Mississippi Valley, followed by a period of Delta construction and valley filling. According to their isostatic models, this 2-phase erosion and then construction in the Lower Mississippi Valley produces up to 9 m of uplift that would effect 150 km of coastline! In other words, the sea-level signal recorded in the Mississippi Delta is a relative sea-level curve (of course), but in addition to having to deconvolve eustasy and sediment compaction, we also have to care about erosion and sedimentation in the attached lower Mississippi Valley as a cause of isostatically driven surface deflection! Pretty neat (and complicated)!

Blum et al (2008) point out that this isn't a Mississippi-only thing, either; deltas are attached to rivers, and in the big ones, we need to be aware of what the record of sedimentation and erosion is. In other words, changing the sedimentary volume drives not only the source-to-sink mass balance of clastic delivery, but can also have an effect on uplift and subsidence patterns in the system.

WORKS CITED:

Blum, M.D., Tompkin, J.H., Purcell, A., and Lancaster, R.R., 2008, Ups and downs of the Mississippi Delta: Geology, v. 36, p. 675-678.

Coleman, J.M., 1988, Dynamic changes and processes in the Mississippi Delta: Geological Society of American Bulletin, v. 100, p. 999-1015.

Tornqvist, T.E., Gonzalez, J.L., Newsom, L.A., Van de Borg, K., De Jong, A.F.M., and Kurnik, C.W., 2004, Deciphering Holocene sea-level history on the U.S. Gulf COast: A high-resolution recrod from the Mississippi Delta: Geological Society of America Bulletin, v. 116, p. 1026-1039.

Book Cliffs Channelform

2009-11-02T06:51:00.000-08:00

Just a quick post of a nifty photomosaic from a roadcut, north of Price, UT. Behold (to quote The Bard: "Methinks that thou shouldst Clicketh, and lo! It doth have a greater size")!

A nice, simple, straightforward, channelform complex, with a couple-or-three accretionary macroforms forming the bulk of the channelform sandstone body. Note the differential compaction of the underlying coals in relation to the hefty sands that got emplaced over it!

"The Thing on the Fourble Board" - Halloween Geology!

2009-10-31T08:55:00.001-07:00

It's Halloween again and, just like last year, I've got some geology- themed horror for you all to enjoy! As we all know, Science is the unholy pursuit of Knowledge That Man Was Never Meant To Know. And the MOST blasphemous of all sciences is geology, seeing as how we seek to understand the inner workings of untold epochs and the secret histories of Earth's unimaginably ancient past; I mean, that's a given, right? An exploration of the horrors that lurk in the dark recesses of the ancient Earth form the center piece of the radio play "The Thing on the Fourble Board", an episode of the horror show "Quiet, Please" from 1948 (downloadable from the link I just gave you).

The radio show takes place on an oil derrick (as evidenced by the the title: a "fourble" is a catwalk on a derrick that's four pipelengths high off the bushing) somewhere in Pennsylvania. After drilling deeper than anyone had ever drilled before, the rough necks come across...something from deep within the Earth.

Anyway, "The Thing on the Fourble Board" is probably one of the best, legitimately spooky pieces of horror radio out there (especially the weird vocalizations of the The Thing itself). And it takes place on an oil derrick (and, come to think of it, would be one hell of a "Safety Moment" back at Oil Company HQ). Anyway, sit back and enjoy some Halloween themed geology with "The Thing on the Fourble Board".

Happy Halloween!

Hawk vs Duck

2009-09-27T09:21:00.000-07:00

Just a quick picture, taken from the loading bay in our department, of a hawk, enjoying a leisurely meal...

...actually, it's a little ominous, I reckon.

Kiwi Research Information Service

2009-09-14T12:48:00.001-07:00

Lookit here! There's a one-stop gateway to all sorts of tasty, free (i.e., SOCIALIST), open-access research documents from a whole bunch of New Zealand research institutes anduniversities. This, of course, includes a fair bit of geology relating info, too. Nifty and convienient, which is what I would expect from Middle Earth.

Above: New Zealand Petroleum Research Institute

Remember when Science was rad?

2009-09-14T12:34:00.000-07:00

Whew! A busy start to a semester, what with seminars and teaching and paper work and writing and oh yeah GSA isn't that far off so gotta get that talk done (well, started, actually). In amongst all this bullshit that you've got to put up with in schoolin', it's sometimes hard to keep sight of the reason why you got yourself into the mess that is grad school in the first place, you know?

There's a series of Op-Eds at The New York Times website, ostensibly for incoming freshmen, about how to get the most out of your college experience. All of them are written by big-wig academic types with hugely famous reputations, and some of the advice is a mixed bag (and some is hilariously predictable, given the writer, fer' instance: Harold Bloom thinks people should read the classics. Who'd a thought!?!). Anyway, there is kind of a neat one by Nancy Hopkins, on the excitement of Your Chosen Field, which is pretty good, I think.

Now get back to work!

Mud as Sand!

2009-09-07T07:18:00.000-07:00

Mud is, as we all know, an important component in the sedimentary rock record, and in some successions, completely dominates the record. The picture below is from around Grand Junction, Colorado, USA, and shows a thick package of the Mancos Shale, deposited in the Western Interior Cretaceous Seaway. I don’t care who you are or where you’re from, that’s a lot of mud!

Anyway, mudrocks (encompassing silt- and clay-sized grain populations) occur across the depositional landscape, from floodplains to abyssal plains, and are easily the third-best grain size out there (the others, sand- and gravel-sized particles, are tied for first in the “best grain-size” category). And that grain-size holy trinity (mud, sand, gravel) represents the methodological hydrodynamic triumvirate that most sed/strat types deploy (almost casually) in the field: mud is deposited in low energy conditions, sand takes some energy to shift around, and gravels need quite the push to get moving through a system.

There has been some recent, ahem, erosion, of that venerable concept of quiet-water suspension fall-out of mud, however; recent work, both field-based and experimental, are beginning to show that muds may be a little more complicated than just the “fine-grained, laminated, organic rich --- 50 meters thick” nonsense that gets slapped down in your field book.

Schieber and Southard, 2009 pulled off a rather nice, simple flume experiment using mud (in the 10 – 20 micron range) in both fresh and saltwater. They were able, through careful use of time-lapse photography, observations on ripples that became attached to the flume wall, and by quickly draining the slurry from the flume, to capture a variety of ripple formsets made entirely out of mud! The data repository for the paper has some slick movies of the mud ripples forming and migrating, as well. The picture below is their Figure 1, on pg. 484. That there’s a ripple, a-yup.

Anyway, the neat-o thing about this ripple is the kind of sediment transport these muds are experiencing. It was possible, for example, that the muddy ripples just looked like sandy ripples, but were being deposited as fine-grained, turbid slurries, which would still be a fairly low energy condition for ripple formation, right? However, Shieber and Southard 2009 have shown that, in fact, the muds rapidly flocculate into silt and sand-sized particles, which are then transported at comparable velocities to regular ol’ sand and silt grains.

Of course, the implications are pretty obvious: previously interpreted quiet-water offshore muds, for example, might not be as quiet-water as we thought. And, post-depositional burial and compaction might result in the general obliteration of these ripple cross-laminations and bedforms from the record, and the superficial appearance of horizontally laminated mudrock. That really changes your interpretation of hydrodynamics, sedimentation rate, and how the mudrocks fit into whatever lithofacies association scheme you’ve cooked up for your rocks.

Wright and Marriott, 2007, came to the same general conclusions regarding mudrock in the Lower Old Red Sandstone (South Wales, UK). These mudrocks generally lack the stereotypical “fine-scale laminations” of most mudrocks; because of this, the assumption has been that these muddy units have been altered by soil formation. However, Wright and Marriott 2007 point out that these mudrocks are often interbedded with gravel-lens that have sharp contact (above and below) with the mudrock, that there are sharp truncations that separate mudrock from other mudrock, and that there are some faint, large scale architectural components associated with these mudrocks, reminiscent of accretion packages in fluvial macroforms. The picture below sums up, diagrammatically, their own field-based evidence for these interesting mud associations; it’s Wright and Marriott’s Figure 3, on pg. 95.

Wright and Marriott (2007) point out that this is sort of a big deal. The interpretation of muddy deposits as relatively continuous, flat-lying overbank deposits with lots of pedogenesis is FUNDAMENTALLY different from the interpretation of mudrock deposited as sand-sized aggregates within a channel complex. Hydrodynamics, Time, and Sedimentation Rate…there are big differences between these two models. And, from a practical side, if I’m depositing mud-rich plugs in an active channel as macroforms, that is going to really change fluid migration paths for hydrocarbons within the ostensibly permeable and porous channel complex sandstones.

Anyway, kind of a neat thing to think about, next time your haulin’ ass over the mudrocks to get up there at the obviously more interesting sandstones. Maybe these fine-grained bedload phases are more common than we realize?

WORKS CITED

Schieber, J., and Southard, J.B., 2009, Bedload transport of mud by floccule ripples – direct observation of ripple migration processes and their implications: Geology, v. 37, p. 483-486.

Wright, J.P., and Marriott, S.B., 2007, The dangers of taking mud for granted: lessons from Lower Old Red Sandstone dryland river systems of South Wales: Sedimentary Geology, v. 195, . 91-100

SedPortal

2009-09-01T08:34:00.000-07:00

Well, sadly, I'm back from the field...however, having to deal with the dismal, post-field depression is somewhat mollified by the soothing, minty balm that is the geoblogonetosphere. ANYWAY, just thought I'd point out a recent (?) addition to that august electron-based sed/strat portion of the web that I (and a few others) reside in. Boyan Vakarelov is a lecturer in Sed/Strat at the University of Adelaide, and also runs the website SedPortal, which has some nifty stuff. Welcome to the HiveMind, Boyan!

Nifty stuff from the Utah Geological Survey

2009-08-19T10:47:00.001-07:00

Hup! Just a quick post about this thing that I recently found. The Utah Geological Survey has made up some of them there KMZ files that the Google Earth Folks are so hyped-up about, letting you drape a 3-D geological map over the terrain around St. George, Utah. Pretty spiffy, really. They also have a virtual field trip that makes use of the crazy 3-D map, which is a pretty neat thing. All in all, a pretty cool use of the ol' Google Earth.

Anyway, back to work!

Might as well post a picture, while I'm at it...

2009-08-11T10:28:00.000-07:00

Since I'm in town, using that there internets to do my patented "Last Minute Abstract Submittal" to GSA, I thought I'd slap up a picture of some nifty soft-sed deformation. Here you go (in the words of the Prophet, "Click it, and it shall be Bigger"):

This picture is from some Cretaceous deltaic stuff exposed on the Rock Springs Arch, a little east of that shining beacon of metropolitanism, Rock Springs Wyoming. A picture of this very outcrop is in the "Roadside Geology of Wyoming", making it famous, I guess. That same book probably also tells you the name of the unit it's in, which escapes me now (I THINK it's Mesaverde Group, but I can't get any finer scale than that).

Anyway, you can see the nice folding going on in these slippery, mudrock and sandstone prodelta interbeds. If you look REALLY close, near the core of the fold, there's a little red stripe of something...that's my rockhammer for scale. The metal post on the right is a Speed Limit Sign, which is maybe 6 or so feet tall? So it's a good sizes feature. If you're every heading out on I-80, this outcrop is right on the westward-side of the interstate, a few miles before you get to Rock Springs proper. Take a look!

Field Pictures

2009-07-30T08:17:00.001-07:00

Gotta get a post in before July vanishes! I've been out fieldin' it up in Wyoming since mid-June or so, which has resulted in a SHOCKING lack of updates; luckily for me, the geoblogosphere gets pretty quiet come the summertime, which I choose to interpret as evidence for Milankovitch cyclicity as an allogenic forcer on the internet. THERE IS NO OTHER VIABLE INTERPRETATION.

Anyway, thought I'd just post up a quick few pictures of the pretty scenery out West; maybe at the end of the field season I'll put some sed/strat specific pictures up, but these ones below are more of your "Gosh-golly-geewilikers! Purty!" type of pictures.

This first picture (below) shows the Green River Formation (Eocene); the yellowish-tan stuff at the base of the cliff is the Tipton, while the white-colored interval (shot through with some pretty rad brown sandstone) are the Wilkins Peak Member (that's my baby). The river in the background is the Green, making the Flaming Gorge Recreation Area behind a dam.

This next picture is Exhibit #34591 in the continuing series "Rocks That Have Been Shaped Into Rude And Amusing Shapes"; its a pinnacle made up of the volcaniclastic-rich deltas of the Sand Butte Bed, which marks the fillin' in of Eocene Lake Gosiute. On the topo maps of the area, this feature is referred to as "South Chimney Butte"; the Locals have another name for it.

This picture is of the Green River Formation, expressed on the EASTERN side of the Rock Springs Arch, sort of near(ish) to the town of Wamsutter. The red-n-green funtime strata are alluvial and fluvial strata of the Cathedral Bluffs Member (equivalent to the Wilkins Peak on the West flank of the Arch), while the lakey lookin' white tannish/whitish stuff in the Laney Member of the Green River Fm.

Finally, here's a picture of a Hawk that was yelling at me for a good couple of hours. I must have been taking paleocurrents in it's living room, since there was a huge nest not to far away from where this picture was taken.

All right, back to the Field!

Summer Reading Meme

2009-06-09T08:35:00.000-07:00

Contagion once again sweeps the geoblogs, this time in the form of a Summer Reading Meme; the original infection spread quickly from Suvrat to Brian, and currently threatens the whole of the Developed World. NOW DO YOU SEE THE DANGER OF THE ANTI-VACCINATION CROWD!?!

Anyway, I've obviously succumbed to the hellish meme-fever myself, 'cause here's my summer readin' list:

Beyond the Hundredth Meridian: John Wesley Powell and the Second Opening of the West, by Wallace Stegner, followed closely by:

A River Running West: The Life of John Wesley Powell, by Donald Worster; I'm still on my Powell kick from LAST summer out in the Green River, and these two books are pretty much the definitive scholarly examinations of Powell's life, career, and his subsequent impact.

Bigfoot: The Life And Times of A Legend by Joshua Blu Buhs; I wrote about this one here, and from what I've heard, it's gonna be a pretty rad book, examining the myth of Bigfoot, the people who "study" it, and the role that the Big Hairy Ape plays in gender-class-race dynamics. Neato!

The Black Lizard Big Book of Pulps, edited by Otto Penzler: I've always loved the pulpy goodness of 20's, 30's and 40's magazine fiction, and this collection has 1100+ pages of Detective fiction from the pulps!

Now go wash your hands and drink some Orange Juice, lest ye be infected by the Meme!

More Damn Tafoni!

2009-06-07T07:45:00.000-07:00

Michael has put up yet more Tafoni pictures, obviously still stinging from my earlier usurpation of the whole tafoni pictures thing. As such, I shall respond with yet more images of these artsy weathering pits in sandstones! The picture below is from the Ordovician St. Peters Sandstone, in Governor Dodge State Park, Wisconsin, where I was on a little camping jaunt earlier in the week.

Anyway, you might notice that Michael's pictures from the Santa Cruz Mtns are much better than my picture above; this is undoubtedly due to the fact that 1) His Rocks Are Better Than These Scrappy Ord. Ss from Humid Wisconsin; and 2) He Is A Better Photographer Than I Am. Both of these are rather unfair advantages, frankly, and Michael should be ashamed of himself for exploiting them so mercilessly like that.

A life-sized Whale, in the comfort of your own Home

2009-06-01T20:05:00.000-07:00

Check this out! It's a life-sized whale, put up on your computer screen; you can click and drag all over the critter, and get a sense (sort of) of just how big it is. Those with access to really nifty huge computer screens will have the best views, of course, but still, kind of neat!

The whale is a part of the Whale and Dolphin Conservation Society, and is part of a campaign to get people thinking about Cetacean conservation. It's kind of neat use of visual media, don't you think?

Earthquakes and the Wrath of God!!!!!!!!!!

2009-06-01T11:29:00.000-07:00

It's not just our crazy, US, Christian-flavored fundies that have wacked-out ideas! The recent seismicity in Saudia Arabia has inspired some End-O-The-World, Koranic musings from the Saudi Gazette. Go here to read about the Wrath-o-Allah! My favorite quote, of course:

Their argument about earthquakes being the result of natural geological activity holds no more ground than a claim that this published article on paper or website is a result from the functioning of a machine (printer or computer) without any effort of a human brain behind it that has made it make sense.

Just kind of nice to see other folks getting in on the geo-madness, you know?

Alexander von Humboldt Celebration

2009-05-31T11:46:00.000-07:00

Summertime's gettin' here FINALLY, and with it, the blessed relief of FIELD WORK!!!! Still a few weeks to go, of course, but we're gettin' there, slow and steady!

Anyway, to celebrate this auspicious annual event, let's remember the scientist who for all intents and purposes, is the Patron Saint of Field Work...Alexander von Humboldt! May 2009 is the 150th anniversary of this great scientists death (specifically May 6th, so we're a little late). Humboldt was a German naturalist and botanist, and was famous for his extensive field work in Latin America...and I mean EXTENSIVE. Ol' Humboldt was one of the first "modern scientists", who went about his work in Latin America with that monomaniacal methodical madness that signifies the True Field Scientist (TM).

If you've read The Voyage of The Beagle, then you'll know that Humboldt's careful methods and emphasis on field data were a major source of inspiration to Charles Darwin. And, of course, you've heard of the Humboldt Current, right? Named after him! Read some more about him here!

Anyway, when you're lucky enough to be out in the field, doing some work and engaging in the tried and true method of field science, give a tip o' the hat to Alexander von Humboldt, one of the Greats!

Cryptozoology and the History of Science!!!

2009-05-11T09:43:00.000-07:00

It's long been known that the psuedo-sciences are bad for your blood-pressure, whether it's creationists or homeopaths or AIDS/HIV deniers or Anti-Vaxxers or Embiggening Earthers. They just make me mad! But of all the pseudo-science wacknuttery out there, I actually have a great deal of sympathy for the poor, lonely, grumpy Cryptozoologist.

Of all the branches of the pseudo-scientific tumbleweed that blows around the fringe-intellectual landscape, cryptozoology is the closest thing in spirit to Real Science (TM). The cryptozoologists are a lot like us, in that they have a legitimate love of critters, the environment, and the general rad-ness of the World. Of course, where we find beauty and wonder in the scientific exploration of the world around us, the cryptozoologist eschews biology and ecology for a more populist-style of old school prophet/naturalist, wandering the wilds and shaking their fists at the rest of us. Still, given as much disdain as they often show for basic field biology and science in general, I love 'em anyway! It's hard not to be charmed by their enthusiasm (often evidenced with just a hint of vitriol on the pre-eminent cryptozoology site on the web, Loren Coleman's Cryptomundo site); you can see something of what made us all go into the sciences reflected in their wild-eyed cryptid hunts.

Of course, the REALLY interesting part of cryptozoology is that skewed nature; what makes some folks into cryptozoologists, and makes others into biologists? And what makes cryptozoology so damn interesting to the public at large? Good luck finding something on The Science Channel or Discovery dealing with the intricacies of ecology, or the comparative anatomy of coelomates! But I guarantee that there is a show on RIGHT NOW about Bigfoot or Alien Big Cats or Mkoele Mbembe somewhere on one of those "scienceish" channels. Why!?!

Well, due to my inside track to the world of The History of Science (thanks Megan!), maybe we'll have some scholarly insight into Cryptozoology world. Joshua Blu Buhs has written a book entitled Bigfoot: The Life and Times of a Legend (click on the link for an excerpt and and interview). The synopsis of the book sounds pretty nifty:

Last August, two men in rural Georgia announced that they had killed Bigfoot.
The claim drew instant, feverish attention, leading to more than 1,000 news
stories worldwide—despite the fact that nearly everyone knew it was a hoax.
Though Bigfoot may not exist, there’s no denying Bigfoot mania.
With Bigfoot, Joshua Blu Buhs traces the wild and wooly story of America’s favorite homegrown monster. He begins with nineteenth-century accounts of wildmen roaming the forests of America, treks to the Himalayas to reckon with the Abominable Snowman, then takes us to northern California in 1958, when reports of a hairy hominid loping through remote woodlands marked Bigfoot’s emergence as a modern marvel. Buhs delves deeply into the trove of lore and misinformation that has sprung up around Bigfoot in the ensuing half century. We meet charlatans,
pseudo-scientists, and dedicated hunters of the beast—and with Buhs as our
guide, the focus is always less on evaluating their claims than on understanding
why Bigfoot has inspired all this drama and devotion in the first place. What
does our fascination with this monster say about our modern relationship to
wilderness, individuality, class, consumerism, and the media?
Writing with a scientist’s skepticism but an enthusiast’s deep engagement, Buhs invests the story of Bigfoot with the detail and power of a novel, offering the definitive take on this elusive beast.

I don't know if the cryptozoologists out there are going to like it, but I think it sounds pretty neat! Might make some good readin' for the field, while we're out there contemplating geology and the wonder of the real world!

Tafoni!

2009-05-09T10:18:00.000-07:00

A quick post as the semester wraps up (finally!), illustrating tafoni! Huzzah! The two pictures below are from the Wilkins Peak Member of the Green River Formation, in SW Wyoming.

Tafoni are scoopish-pits in granular rocks (like sandstones...) that are (probably) caused by weathering of differentially cemented zones in the rock.

And by the way, "tafoni" is apparently the plural...the singular is "tafone". Now you know!

EDIT: Yet more Tafoni on the internets! Check out Michael's post on his blog, Through The Sandglass!

EDIT EDIT: Jumpin' Cats! Michael is the Tafoni King at his blog...AND I HAD NO IDEA! Here and Here! Read!

What's the harm?

2009-05-06T11:09:00.000-07:00

Well, Spring has certainly sprung! Leaves are greenin' up, sun (and rain) is back in the forecast, and the steady creep of "Field Season Anticipation Madness" (FSAM) is slowly overwhelming my ability to sit and work in the dept.

Anyway, if all this springy weather is making you feel TOO HAPPY, you can always go over to What's The Harm? and read some horrible stories of people dying due to stupid psuedo-science and ridiculous superstition. Nothin' like some awful stories of human ignorance and death to take the edge off that sunny afternoon, right!?!

Fixin' Edumacation...

2009-05-04T14:29:00.000-07:00

As bad as some folks think grad school is, there are WORSE ways to go about it...

Seized (violently) from here.

Maybe this whole "education" thing isn't as bad as it could be!

"Graduate education is the Detroit of higher learning"

2009-05-02T13:09:00.000-07:00

Mark Taylor, the Chair of the Religion Dept at Columbia, has a pretty interesting Op-Ed piece in the New Yorker, entitled "End the University as We Know It". It's a pretty radical piece of writing that advocates a complete restructuring of the University System, and especially grad school. In fact, the piece starts off with:

Graduate education is the Detroit of higher learning. Most graduate programs in
American universities produce a product for which there is no market (candidates
for teaching positions that do not exist) and develop skills for which there is
diminishing demand (research in subfields within subfields and publication in
journals read by no one other than a few like-minded colleagues), all at a
rapidly rising cost (sometimes well over $100,000 in student loans).

A pretty grim pronouncement...with an uncomfortable degree of truth, probably.

Anyway, Taylor suggests that higher education is in dire need of complete restructuring. To this end, he suggests that we take the following steps:

1. Completely restructure the curriculum: Taylor wants to get rid of the tiered learning structure, and replace it with a "web-like" system of learning and scholarship, with an emphasis on cross-disciplinary education, which leads to his second point...

2. Abolish permanent departments: Taylor does not like the traditional disciplines. Rather, he suggests organizing university programs around questions or research problems, drawing on a range of expertise to interrogate a variety of topics.

3. Increase inter-institutional collaborations: and Taylor doesn't want to just stop there...he wants different universities and institutes to augment their research with workers from elsewhere.

4. Kill the standard model of The Dissertation: probably the easiest sell, right? 600+ page tomes that no one will ever read, AND you have to re-format everything anyway to gets papers out of it? Yes please.

5. Expand the range of professional options for grad students: meaning that they don't JUST TA or RA for their Profs, but do other things (Taylor is a little vague, here)

6. Impose mandatory retirement, and abolish tenure, requiring professors to keep their work new and exciting.

While I agree with the frustration that Taylor feels for higher education (ESPECIALLY in regards to the Dissertation and getting rid of tenure for profs) , I'm not sure if this is the right way to go about reformatting the University. In particular, the perpetual call for "more interdisciplinary work" is always a little bothersome; what exactly is meant by "more interdisciplinary", and how are you supposed to implement it without a sound grounding in the basics of some standard discipline?

What do you guys think?

Walpurgisnacht Madness!

2009-04-30T07:18:00.000-07:00

Did you know it's Walpurgisnacht today!?! Like Halloween, today (and tonight) is supposed to be a particularly dangerous time, in regards to ghosts and witches and general weirdness bleeding through into our "reality-based" world. I'm a sucker for tradition, so in honor of this spooky time, I though I'd share something insane with everyone:

Read THIS and then THIS.

Actually, I might ought to warn you, the first link up there has some...uncomfortable moments. Everyone always brings up the cliche of the car wreck ("can't help but look"), but those links up there? The story linked above isn't so much of a car wreck as it is...a schoolbus-full-of-Hospital-visitation-clowns-that drove-off-of-a-cliff-and-into-the-Large-Hadron-Collider sort of wreck. That sort of thing. You can't help but look!

Anyway, to sum up the insanity here, Neal Horsely is the Georgia Gubernatorial candidate and head of "The Creator Rights Party", which is everything it sounds like. Standard issue wackjob crazy Creationist, with the whole "literal bible, hyper-conservative, anti-fun" sort of stance. Nothing new there. He wants Georgia to secede from the Union so it can live in a more biblically-inspired (i.e., insane) way, ostensibly with him at the helm. He's violently anti-abortion (he's the one who set up the "Nuremburg Files", which listed abortion doctors' phone numbers and addresses), and has contacts with that whole insane group of doctor-murdering "Christians" that we used to hear so much about.

And he has admitted to having sex with a Mule, so there's that.

Frankly, for these sort of ultra-conservative radicals, it sounds like everyday is Walpurgisnacht!

Cambrian Hermit Arthropods

2009-04-28T13:53:00.000-07:00

The evolution of land animals is one of those iconic geological/paleontological images, even percolating into the popular culture as a symbol of progress. What is interesting, of course, is that popular representations of this seminal event are usually of the fish-to-lungfish-to-vague amphibian sort; what people seem to forget is that the first animals to CONQUER LAND (insert echo here) were invertebrates, bravely going were no metazoan had gone before!

In the past, the first known tracks were thought to belong to an Arthropleura like myriapod (pretty much, a centipede). These tracks are from the Joggins, in Nova Scotia, and are early Silurian in age. Horribly, these tracks seem to suggest that the myriapod that made them was enormous; the picture below, lifted from here, shows a model of one:

Now, however, the earliest terrestrial land animal tracks might belong to a Cambrian arthropod that used a discarded shell, a la Hermit Crabs, to prevent drying out on subaerial tidal sand flat. A recent paper in the April issue of Geology (here's the abstract) by Hagadorn and Seilacher (2009) shows trackways with a peculiar, segmented, shingled-to-the-left tailmarkings. The picture below is their Figure 1 (pg. 295):

The interpreted ethology (that is, behavior) of the critter is labelled in this picture below, Hagadorn and Seilacher (2009) Figure 2 (pg. 296):

These traces show a marked similarity to the traces of modern Hermit Crabs, whose borrowed shells also bump along behind them as they wander the beach. The picture below is of a modern Hermit Crab trace from the Bahamas, and was seized from the Data Repository Items for the paper:

Anyway, the interesting part of this paper is WHY the critter might have carried a shell around behind it. These tracks are found in the Cambrian Elk Mound Group of Wisconsin, and are commonly associated with microbial mats, elephant-skin textures, microbal sand-balls, and other sedimentary structures that suggest extremely shallow to subaerially exposed conditions. One of the reasons that Hermit Crabs lug their shell around is that it serves as a reverse-SCUBA suit; in other words, the Crabs can bring a damp, humid shell along with them to keep their gills in proper working order.

Hagadorn and Seilacher (2009) suggest a similar strategy for this Cambrian tracemaker. The tracks themselves show that the shell was far to small to house the entire critter. Rather, they interpret this as an early behavior that allowed these Cambrian arthropods to exploit the subaerially exposed sand-rich, microbial tidal flats along the Paleo-Wisconsin shorelines. If that's the case, then this is one of the very earliest strategies employed by terrestrial (or at least, amphibious) animals, and it's a pretty derived behavior to boot!

WORKS CITED:

Hagadorn, J.W., Seilacher, A., 2009, Hermit arthropods 500 million years ago?: Geology, v. 37, p. 295-298

For Sale: Columnar Basalt, Slightly Used, May Be Divine

2009-04-26T11:28:00.001-07:00

Wanna see something silly? This. That is silly. Silly enough to end up on CNN, even.

Yup, some wacked-out chowderhead from Idaho has put up some columnar basalt outcrop in his backyard for sale on E-Bay. He claims to see the Hand o'God in the outcrop, which bestowed some sort of magical economic relief to his depressing life, or something. And as of this writing, he's got an offer of around $670 for it, too.

Well, not for It, actually. Just the "rights to it", whatever the hell that means. Still, how often do you get the chance to own some MAGIC basalt? Bid now, geobloggers!

Sed Sunday - Shell beds and shell lags!

2009-04-26T07:56:00.000-07:00

Shell-rich beds are great stratigraphic markers and, despite commonly being fairly thin intervals, can provide a lot of information regarding paleoenvironment and paleohydrology. They represent a pretty subtle linkage between biology, sedimentology, and stratigraphy that serves to elucidate complexly interacting attributes of the rock record, especially in regards to sediment accumulation, substrate consistency, and water quality (to name a few!).

Anyway, I thought I'd show a few pictures of shelly intervals for this Sed Structure Sunday. The picture below is from Egypt, and is a good example of a compound bed. Several distinct horizons of different types and abundances of shelly fossils indicate that, despite the thin-bedded nature of this interval, a lot of time is wrapped up in this horizon.

These next two pictures show horizons dominated by a single type of bivalve, Carolia (not sure if that's spelled right...but it's at least a phonetic spelling of the right genus...), showing it's characteristic thin shell. These are from Egypt as well. These are pretty much in-place, as indicated by their delicately articulated shells, and tell us something about the low-energy, clear water conditions of these deposits.

This is in contrast to the picture below, which is also from Wadi al-Hitan, Egypt. It's a big, thick-shelled Pycnodonte, pretty isolated, in a single interval. Upsection, these guys become more abundant, and are eventually overtaken by (and overgrown with) smaller Gryphaea and Carolia beds.

And this last picture is from the core I was measuring last week; it shows a different kind of shelly interval than the previous pictures. Whereas those pics above show in-situ shell beds, this picture shows an erosional scour and shelly lag. These busted up bivalves were transported as bioclasts, and deposited like any other grain in a siliciclastic system.

Jared Diamond in Trouble

2009-04-25T09:09:00.000-07:00

Jared Diamond, of "Guns, Germs, and Steel" fame, is being sued by two citizens of Papua, New Guinea, for allegedly fabricating a story of violence and revenge for a New Yorker article in 2008. The article (which has been taken down, though the abstract can be read here) tells about a feud involving a stolen pig that supposedly resulted in a horrible series of revenge-killings, culminating in a body count of about 17, with numerous injured parties as well. Diamond apparently uses the story to illustrate something about revenge and violence in culture, contrasting the Papau, New Guinea incident with the story of his father-in-law's rejection of revenge in favor of using more civilized methods of discourse (i.e., the Police).

The problem is (well, aside from the disturbing subtle racism in the article) is that Diamond apparently made the whole thing up. Numerous quotes, attributed to the Papaun tribesmen in the story, are apparently amalgamated reminiscences of Diamonds, rather than actual quotes; these faux-quotes were strung together into a longer narrative, undoubtedly to give the story a little more heft (in my opinion, a very common tactic in Diamond's works). Also, apparently the story of the feud is made up whole cloth, while some of the violence described coming from events that happened years before Diamond's story.

You can read a painstakingly detailed examination of the claims here, including a discussion of the lawsuit and the dangers the men who filed it say they are facing due to Diamond's falsehoods.

All in all, it's pretty grim stuff, both legally and scholarly. I've always found Diamond's work a little troubling, anyway; his "Guns, Germs, and Steel" was an exercise in poor scholarship, both in the interpretation of other peoples work as well as failing to cite the people who actually came up with the ideas in the first place.

Look, the guy ISN'T an anthropologist; he's an anatomist. He has NO training in the social sciences, in history, or in human or cultural geography, which is exactly what he's been writing about for years. By the by, ol' Diamond REFUSES to give talks in History or Geography departments anymore. Kind of telling, don't you think? Maybe this will make people stop and evaluate some of his other works as well.

Joe Barton - Stupid Bastard

2009-04-23T15:58:00.000-07:00

Thank god for our elected officials! These tireless servants of the public good are working themselves to exhaustion, making sure that we AMERICANS have the proper level of accountancy in our horrible, socialist, marxist, muslim government. A good example of this sort of hardworking, decent, salt-of-the-Earth (you know...a moron) type is Rep. Joe Barton, of the Great(ly Stupid) State of Texas.

In case you haven't heard, lil' Joey Barton asked Steven Chu (PhD, Nobel Laureate, Smart Guy) to explain WHERE THE OIL COMES FROM IN ALASKA. In Six Seconds. Six Seconds to explain 100+ My of plate tectonics, subsidence, and paleoenvironments. In case you wanna see the full splendor of this asinine question, check it out here.

If you take a gander at that video above (or the transcript), you'll see the REAL POINT that Joe Barton (not PhD, not Nobel Laureate, Suspected Chronic Masturbator) wanted was Chu to admit that ONCE IT WAS WARMER IN ALASKA, which, I don't know, proves Jesus or defeats global warming or something. Anyway, if you want to see some gloriously arrogant ignorance on Barton's side, take at look at this video that his office put out (via Wonkette, of course), where he gloats about his "stumper" (which, as I type it, makes me feel very queasy and uncomfortable). Too, Barton bragged about his Victory Over Smartness on twitter, which just confirms my old theory that the guys who named "twitter" are actually cunningly making fun of most everyone on it.

Anyway, the point is, Barton is a jack ass and an idiot. If only there was some wordsmith, some comedy-smelter, who could take this cold ingot of stupidity and forge it into a sword of cleverness with which to smite Barton the Stupid!?!

Oh, that's right. David Rees is just such a man. Clicky clicky on the link, sit back, and watch the master at work.

Jumpin' Cats! It's Earth Day!

2009-04-22T11:57:00.000-07:00

I'm celebrating Earth Day by describing core down at the BEG in Austin, TX, which means I flew there, which means my Carbon Footprint is HUGE...and you know what they say about guys with Big Footprints, right? (ANSWER: They are socially and ecologically irresponsible).

ANYWAY, a brief post, just to make sure I remember how the internets work. Check out some Earth Day Jokes from David Rees!

And look! Here's a picture of some rocks, which are found on Earth! Neat!

OOHH! EDIT: Lookee here, geo-enthusiasts! The Comics Curmudgeon has a special Earth Day Edition of his always insightful, hilarious, and all around rad daily analysis of the Funny Pages. Enjoy!

Sunday Sed Structures - Evaporite Casts!

2009-04-12T14:10:00.000-07:00

Lookit here! Pictures of sedimentary structures on a sure-fire Sunday, rather than later. What a novel concept.

Anyway, these pictures below show some outcrop exposure of evaporite crystal casts from the Eocene Wilkins Peak in Southwest Wyoming. This first picture below shows a little crystal fan of some sort of evaporite.

These two pictures below show a bedding plane view of evaporite crystal-casts.

That's all...go eat some salt on your hard-boiled Easter Eggs to show some evaporite solidarity!

Green Porno

2009-04-12T11:56:00.001-07:00

Hope everyone is enjoying their pagan-fertility-holiday-whitewashed-with-a-vernier-of-christian-iconography! In honor of the day, why not enjoy some explorations of reproductive biology from Isabella Rossellini (of Blue Velvet fame, among other things...). Her Green Porno series, which apparently is being shown on the Sundance Channel, has some of the most creative uses of paper sculpture you'll ever see. There are two seasons worth up on the website, ready for viewing, each one exploring animal reproduction in some really weird ways! Good Easter Fun!

But don't watch the Fly Episode from Season 1...it gets a little morbidly psychedelic near the end...

Sunday Sed Structures - Fashionably Late Edition

2009-04-06T06:55:00.000-07:00

Monday already! Hot Damn! Being punctual is for considerate, thoughtful losers anyway! Here's your (late) sed structure picture for the week!

Imbricated fusilinids! This picture is from the Guads, right off the Permian Reef Trail. The trail is pretty darn slick, allowing you to walk up through the stratigraphy of a Permian Reef buildup. The toe-of-slope deposits are commonly dominated by calciclastic debris, often in the form of thin, fossil-rich turbidites. Anyway, the picture above shows some big ol' forams that have been washed down from behind the reef, in the process getting sorted and imbricated.

See!?! Hydrodynamics ARE important in carbonates!

Bureau of Economic Geology Podcasts

2009-04-06T06:40:00.000-07:00

You're never to busy to listen to podcasts, right!?! I just found out about the BEG's Geo-flavored podcast Time On Earth, which you can subscribe to via the iTunes or as a direct-from-tube download on that there internets. Nifty, huh? It's only once-a-month at this point, which is kind of a downer, but still! One more geoscience podcast is always a good thing!

Sunday Sed Structures - MONDAY EDITION

2009-03-30T06:51:00.001-07:00

Might as well TRY to keep this arbitrary schedule o' mine, I guess! Anyway, briefly, here are some pictures I snapped down in the Guads. No carbonates (yet), but here are some nice pictures of some recent gravelly/cobbley cross-bedding in a modern stream cut. Flow is to the left!

Notice the direction of cross-bedding in ABOVE the fieldbook in the second photo? Kinda goin' the wrong-direction, ain't it? I reckon I'd call that backset cross-stratification, maybe do to the impingment of upper-flow regime conditions on the flow.

USGS Photo Library

2009-03-29T16:02:00.000-07:00

Being out in the Southwest always makes me think about the O.G. (Original Geologists) who totally went out there Hammers-a-blazin', rockin' it Old School Style, nearly gettin' killed left and right, and all that sort of fun stuff. We can all agree that they were badass, but did you know they were also awfully photogenic? IT'S TRUE!

The USGS has a pretty slick on-line library of old photographs of ALL sorts of things, including some totally rad shots of famous geologists in the field. Now, most pictures of modern geologists look pretty silly; if you don't belive me, take a look at any Geology Dept's website. Profs, Grads, Undergrads...it's a well-known scientific fact that they all look pretty goofy! But man, look at ol' One-Armed Powell, there, looking rad and hanging out with a Paiute Cheif! How's that for a slick facebook picture!

Seriously, how's that for a slick picture?

Here he is again!

POWELL: "What's up, my Paiute Friend? I'm a kick-ass geologist! Wanna go cruise around the desert, get some brews, and pick up chicks?"
PAIUTE: "Awwwwww yeah!" *fist bump*
HORSE: "Neigh."

And look at this one! Powell in traditional Paiute gear! Dirty Hippie!

Sed Structure Sunday #2 - Saturday Edition!

2009-03-21T13:43:00.001-07:00

Well, I'm fleeing to the Gaudaloupe Mountains for a carbonate field trip, sponsored by Exxon, so I'm posting my sed structure pictures ONE DAY EARLY!

The picture above (to embiggin it, click the picture) is of some Eocene stromatolite-like mounds from the Washakie Basin (Green River Fm) in SW Wyoming. These little guys formed along the edge of a big, fairly saline lake, and as such mark a discrete geographic boundary in these ancient lake settings.

I realize that I don't have many carbonate pics; maybe I'll have some to share when I get back in a week!

Dolphins: Nature's Fluid Hydrodynamicists

2009-03-20T14:51:00.000-07:00

Jumpin' Cats! Have you guys seen this:

How awesome is that!?!

These dolphins blow a bubble into a turbulently roiling eddy, which causes it to become a bubble-ring (similar to a Gandalf-style smoke ring, actually) and then, being dolphins, decide to play with it in the most ridiculously cute fashion possible. Hydrodynamically, these rings are a kind of toroidal vortex, which in this case is made up of a combination of air and water moving as a kind of propagating vortex. Here are some pictures of human-made bubbles, with a discussion of the physics involved in these things.

EDIT: Turns out a geo-blogger had already talked about this: check out Riparian Rap!

Revenge of The Son of Meme!

2009-03-16T07:47:00.000-07:00

Another hellish meme has been unleashed upon the unsuspecting geoweboblogonetosphere, bringing with it interminable link-backs and crushing despair. Oh well! This particular viral meme (classified as a Level VI List-Maker Meme on the Abradoff Scale by the CDC) is described (based on the experience of the first reported victim) as: “What are ten things that every geology major ought to know about? The only restriction is you're not allowed to list anything that has already been listed by a previous geoblogger. You don't have to list everything, just ten important things.”

Well, when in Kalaupapa, do as the lepers do, I guess! Here's my List of The Ten Things Every Major Should Know About Geology:

1. Hydraulic Geometry: this concept relates fluvial discharge to slope, channel width, channel depth, and velocity, and explicitly shows how delicate adjustments in one can result in changes in the others.

2. Paleocurrent indicators, and how to describe, interpret, and measure them (especially from trough axes)!

3. What are Froude and Reynold's Numbers, and what do they mean!?!

4. That a lithofacies is the sum of all textural, sedimentary structural, and lithological attributes that uniquely defines a given lithosome, and how THIS DIFFERS from a depositional environment model.

5. The basic sedimentary basin types (i.e., retroarc forelands, forearc, etc), and what subsidence patterns generally define them.

6. Why there are locks on the Panama Canal (the Geoid!)

7. The difference between lithostratigraphy and chronostratigraphy

8. How to draw a Wheeler Diagram

9. The timing and location of the major orogenies

10. Walther's Law

Whew! That was a hard one, since the early-birds already took all the EASY ones...I reckon that by the time this little contagion has passed on, we'll have some pretty esoteric lists of expectations for the next generation of geo-scientists, huh?