Wednesday, April 2, 2008

Death Valley Day 2.5 – The Tufa Pinnacles near Trona, CA

Near the exceptionally dilapidated town of Trona, CA, are numerous tufa pinnacles, some close to a hundred feet high (or more), that were deposited in an enormous Plio-Pleistocene lake. This paleolake filled the entire valley, and created wave-cut terraces that indicate a maximum depth of around 300 meters or so.

In map view, the tufa pinnacles are distributed along old faults, where fluids enriched in calcium were welling up from the depths; upon debauching into the lake, tufa precipitated out (potentially with the help of microbes). There are a LOT of these pinnacles distributed through this basin (see the picture below for a partial landscape shot I took), indicating a LOT of calcium coming from these fracture networks.

There are some really weird textures preserved in some of these pinnacles; I get the feeling that figuring these things out would require a fairly crazy carbonate worker willing to devote a good chunk of their life. Interestingly, there are several surfaces preserved on various pinnacles at various heights. What do these surfaces mean? Are they regional, and could they represent…SEQUENCE BOUNDARIES (cue dramatic music)!!!!

As with all precipitates (and much of geology), these things can have an embarrassingly phallic appearance.
Since this is all on BLM land, we decided to camp right there. My friend with the billion-dollar camera took some pretty awesome evening and night-time shots of these features. Under a nearly full moon, these things looked pretty ghostly, lemme tell you!

Coming up next…the BREAK-UP OF RODINIA!!!!


Andrew Alden, Oakland Geology blog said...

You got some NICE shots. I was there Sunday morning March 30, and the wind was vicious under a dark sky. I just drove around the little loop, snapped some pics and took off for home.

Eric said...

Yeah, we were there around the 15th or 16th, I believe...and the wind was an easy 50 mph or so. It got a bit gusty up on top of those pinnacles!

Anonymous said...

Is this the Valley of the Phalli?