Painted Desert

Painted Desert

Sunday, June 07, 2009

If summer falls on a weekend this year, let's have a picnic

This shot was taken about half an hour ago outside our bunk house. The weather has not been very kind to us here in Wyoming... a week of rain behind us and (according to the weatherman) another ahead of us, and now, a blizzard. We have no heat here... my roommates are all in their sleeping bags and I am sitting on a cold metal chair my four pairs of pants barely insulate me from, trying to type with gloves on. We will not be going out in the field today, or possibly ever again.

Not that I mind the weather very much. Snow is fun, and the rain had enough breaks in it that it wasn't completely miserable. We managed to squeeze in a couple half-days of fieldwork last week, as well as some fun:

The first really rainy day, we did some "blacktop geology" wherein we all piled into the vans for a trip into the mountains to look at some older rock than what we've been studying so far. It's older in the mountains because (as you may know), younger sediment is deposited on top of older sediment, so the oldest stuff is the deepest. When plate tectonics thrusts the mountains up, their new steepness allows for rapid erosion, and the young rocks on top are worn and washed away, exposing the older rocks beneath for geologists to study.

Here is Shell Falls, cutting through precambrian granite that is billions of years old. Our instructors said they'd never seen the river this high... usually it's at only 1/5 this flow.

Here we study the lithology of the Darby Formation. The term "lithology" refers to the actual makeup of the rock--its color, what particles it's made out of, the sizes and shapes and orientations of these particles, and other textures. Other things we might want to study could include the relationship of the Darby to other formations... ah, as I write this the camp director has just brought us all hot water bottles... the dip of the beds, and where on the map the formation can be found. But it's good to start with the lithology, because otherwise how would we recognize the Darby when we found it somewhere else?

Note the clouds at the top of the picture. Part of the reason we drove up into the mountains was to look up and see the other formations making cliffs above us, but no luck. What you can't see in the picture is how it's raining... it's not the rain, precisely, that keeps us out of the field, although it's a pain in the neck to take notes in the rain, even with waterproof paper and a space pen. The problem with rain is the bentonite.

...but more on volleyball later. There was a lot of bentonite where I worked last summer, and I spoke some about it, but I have a better understanding of it now. Bentonite is a rock made from smectite, which is a kind of clay. Clays are minerals that have a very particular molecular structure... or structures, as there are many kinds of clay. They form very thin sheets you can see with an electron microscope (in fact, clays are a kind of "phyllosilicate," or thin-sheeted silica-bearing mineral, as are micas), and some types of clay have surfaces that are very attractive to water. They swell when exposed to water; bentonite can grow to 7 times its size, and becomes extremely slippery. This property is highly desirable in some applications; all around us are strip mines and bentonite plants that prepare the rock for its future as a drilling lubricant. However, even a little bit of rain makes a dirt road unpassable. Since most of the sites we need to visit are off dirt roads, that means we have been mostly out of luck for fieldwork.

So we had rather a glut of free time last week. Our wednesday was declared to be our free day, meaning we were supposed to have a working day today (our usual day off), but we know how that turned out. I'd run out of things to do already by wednesday so I went for a four-hour walk in the rain. Here, a composition I call "chimney rock and tractors."

I walked through the town of Shell, pop. 50, including a few peacocks:

...and out to the Cloverly where it is exposed by the highway. Handy of the government to put these signs up for us.

We weren't the only ones affected by the rain. Click on the following picture to read the woes of some of Shell's 50 denizens, as posted in the local post office:

Now. For some reason, the crew out here has become crazy for volleyball, playing up to four hours a day, which reached a peak in last week's chilly, rain-soaked mudfest. Below are reproduced my pictures from this extravaganza, starting with the relatively clean and progressing through the filthy:

This game was an experience for all the senses, thanks to the generous smattering of cow patties in the field, which slowly disintegrated and mixed with the mud throughout the game.

But wait--there's more. The weather also blessed us with a tornado-spawning storm two nights ago, which knocked down branches and trees around field camp. (No, the tornado did not go through camp.) Considering the fact that some of our buildings date from WWII and are generally composed of tar paper and cobwebs, regardless of age, this was a bit nerve-wracking. As the winds picked up the instructors told us to run for the bath house, which was supposedly the strongest structure, although I highly doubt it would have withstood a whole tree falling on it. As we ran, a 50-pound branch fell off a tree and landed ten feet from us.

The storm took its victims among the porta-potties:

And it also knocked the power out. No rest for the wicked, however: we had mapping projects due at 10 PM.

We worked all evening by headlamp. I was concentrating so much on my project I was only vaguely aware of windows being opened so we could bring a propane lantern in, then of a van being driven up and desk lamps being hooked up to the battery so that everyone could have light.

Yesterday we did manage to go out for a half-day in the field, and I have some lovely pictures from that which I'll save for later. It was also laundry day. We have one washer and dryer here in camp and they're for the instructors, so a vanload of us went down to the town of Basin some 40 minutes away for the laundromat. While my laundry was cooking I ran around the (small) town with some other students in the rain, looking for geocaches, which I'd never done before. One of the students went to a geocaching website and downloaded GPS coordinates for caches, then we followed the GPS to the general area indicated, and hunted around for a container with a log book we could sign.

The snow is actually sticking now, it's very wet, looks like Christmas at home. The title for this blog entry is a quote I found in John McPhee's "Rising From the Plains," a book about Wyoming geology and people that would be an excellent read for anyone wishing to imagine themselves out in Wyoming with me. Till next time!

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