Ash Flows and Hot Springs

The past couple days have been good. After four days of mapping in the beautiful Clark Canyon Reservoir area (follow this link for some photos), we handed our maps in on monday night before heading to Anderson Ranch on Tuesday.


We hiked around and Professor Jim showed us some remarkable ash deposits. It was relaxing to just be able to listen out of curiousity and not have a grade riding on it. And then today we drove to Jackson, MT where there is a hot springs that you can soak in.

It was also relaxing, because, well, it's easy to relax when you are sitting in a hot springs and drinking a beer with friends, right?

It's notable that the ash flows and the hot springs are both evidence of how volcanically active southwest Montana really is: The ash deposits are fluvially focused flows derived from an ash fall. According to Jim, what happened is that about ten million years back or so volcanic activity associated with the geologic hot spot currently located beneath Yellowstone park shot a column of hot ash high into the atmosphere. Upon cooling, the column collapsed on itself and spread out over the surrounding area, blanketing everything in up to several feet of the stuff. Rain washed the unconsolidated sediment off the hills and it piled up in river valleys to many times its original thickness (the deposits we saw were over 100 feet thick). These deposits consolidated over time into weak rock called tephra, which is how we find them. After visiting the ash, we hiked to the top of a ridge and got some pretty good views of the valley despite constantly changing weather.

(More photos of the Anderson Ranch area are up on my picasa page)

By the time we got back to Dillon it was pouring sheets of rain -- the first rain of much substance since my arrival almost a month ago. It will blow the fishing out pretty badly for a while. A relaxed evening and morning in the dorms and we were able to muster ourselves to get in the car and drive the hour to Jackson, MT.

Jackson is at just under 6500 feet and it was snowing pretty well when we got there. (This after two days ago when it was 85, sunny, and dry). And to our dismay, the hot springs pool was empty (*gasp!*). Fortunately, it was only temporarily empty for cleaning, which apparently happens on wednesdays. The waters of the Jackson springs are geothermally heated underground by the proximity of molten rock someplace down there. The water comes to the surface and gets pumped around town to people's radiators, heating the buildings at very low cost. Then it comes out of a pipe at the top end of the pool at the lodge, still pretty scalding hot, and helps to relax locals and passers-through. Louis and Clark came through on their trip. One anectode is that since their thermometer was busted by then, they told how hot the water was by how hot they could stand to sit in it. Apparently the journal claims one of them got nineteen minutes, but reports from folks who have read the actual journals suggest this is inaccurate and the springs were much hotter than that (see comment below). Well anyways, it takes a while to fill the pool up so we took advantage of the lodge's collasal fireplace and looked around at the impressive array of dead things' heads on the walls while we waited. Once it was full enough to walk down to the deep end and lie down and be covered, we went for it. It was, of course, still snowing, which made for a lot of steam coming off the water and the nifty feeling of being really warm while cold wind nips at your face. The water of course has traveled a ways from the source by this point and it cools off a little bit in the pool so we were able to stay in a couple of hours before scrambling through the snow and into the lodge to get ready to head back to Dillon (incidentally, I lost my second watch of field camp in the scramble. I think maybe I quit buying watches for a while...)

NOTES:

* One mapping project left before heading to Missoula with the mission of finding an apartment in 3 days. Hoping to find a place cheap enough I can break even on my stipend. Slightly anxious about that...

* Congrats to Carolyn for graduating!

* Preparations continue for the Long Trail hike. How exciting!

* I am thinking about choosing classes for the fall, which brings up the question of what direction to take with my Masters degree and rouses the spectre of the potential for needing to figure out what to do with my life after the degree... oh, bother...