THE DYNAMIC EARTH: A BLOG ABOUT GEOLOGY AND THE EARTH SCIENCES

Thursday, April 30, 2009

Walpurgisnacht Madness!

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!

Tuesday, April 28, 2009

Cambrian Hermit Arthropods

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

Sunday, April 26, 2009

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

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!

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.

Saturday, April 25, 2009

Jared Diamond in Trouble

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.

Thursday, April 23, 2009

Joe Barton - Stupid Bastard

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.

Wednesday, April 22, 2009

Jumpin' Cats! It's Earth Day!

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, April 12, 2009

Sunday Sed Structures - Evaporite Casts!

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

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...

Monday, April 6, 2009

Sunday Sed Structures - Fashionably Late Edition

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

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!