Last weekend PDP and I got to do some camping and hiking in Capitol Reef National Park! This has been one of my favorites for years. As a geology student at Indiana University (a long, long, long time ago), I took a regional geology field class where one of our stops was Capitol Reef. I will always remember it as the prettiest hike I've ever been on.
The "reef" itself is not a traditional reef in the same sense as a coral reef formed offshore. This is a monoclinal fold (for you geology fans!) that stretches for over 100 miles. It was called a reef by the pioneers because it looked just like a barrier that they would not be able to get around. In fact, the Waterpocket Fold that makes up this part of southern Utah was one of the last places mapped in the U.S.!
Here is a view of the rock units exposed at Capital Reef. At the top, the "white" or "buff" color knobs are the Navajo Sandstone. Below them, a cliff forming unit called the Wingate Sandstone. (Both of these sands were deposited by wind in ancient deserts). Lower on the hill are the Chinle Formation (known for petrified wood and uranium) and the bright red at the bottom of the stack is the Moenkopi -- old river deposits.
PDP is in the foreground studying the rock units for a test later. Ha!
We also hiked out to Hickman Bridge, a natural arch in the Navajo Sandstone. It was hot, hot, hot that day -- sometimes over 100 degrees F. This makes hiking difficult and sweaty. The evaporation rate is so high though, you don't stay wet or sticky for long.
Meanwhile -- back in my field area at Cleveland-Lloyd -- I continue to work on my project for GeoCorps. Here I am searching out and identifying the different types of "cryptobiotic" crusts that form in this desert environment. The crusts that form in the dry soils are made of lichens, algae, or moss and are important for protecting and storing water for desert plants, so it is important not to trample them!
That's all for now!
Carla--
ReplyDeleteWhat is the relationship between uranium and fossils? The Chinle's got wood and U, the Morrison's got dinos and U. Hmmm. I wonder if there is a genetic relationship or if it is just a local coincidence.
Cryptobiotic crusts! That is pretty interesting. The lichens, algae, or moss harvest the dew and sunlight? And then lock moisture in the sand below the crust? Clever little beasts.
Speaking of little beasts, remember to be thankful that you aren't teaching this summer and instead are out there in the incomparable beauty. Jealous.
Thanks again for sharing all this. Keep it up!
--Matthew
Matthew --
ReplyDeleteMe thinks that the relationship between the uranium and the fossils/wood is just a local coincidence. The Morrison and the Chinle both have uranium ores. As the uranium dissolves in the local groundwater, it precipitates when it hits the porous organic matter of the bones or wood. The bones/wood might act like a magnet of sorts, resulting in a higher concentration of uranium in the fossils!
As for the desert crusts -- truly they are fascinating. However, now whenever I venture out into the desert, I have to hop from rock to rock to alleviate the guilt of killing millions of tiny crust creatures! Argh!
I take it your class is filled with beasts? Ha! Better you than me! Hope all is well.