[My first long, detail post about this died in a browser crash. I think I'll be a bit briefer this time.]
Last weekend, we headed up the Owens Valley with our pal, B., a geologist at the local college. He was scouting field trip locations for his students. We were just having fun.
The Owens Valley runs north-south along the eastern edge of California, between the rugged, beautiful, 14,000 foot Sierras and the less-rugged, still beautiful, 14,000 White-Inyo mountains. It's the source of the Owens River, which is the water source for much of southern California.
We headed up US 395 in a rented minivan, shooting across the Mojave (uncharacteristically full of blooming plants!) and across a fault and up to Owens Lake, now dry. Since LA started sucking down all of the Owens River, the lake dried up -- strangely enough, a century ago, steamboats served several lakeshore communities, carrying around mining supplies.
B. has spent countless summers in the Owens Valley, doing research, so he was an ideal guide. Our first stop was Fossil Falls, the remains of a 20,000 year old lava flow that has been wildly eroded by ancient streams. The lava is amazingly contorted and looks simply amazing. The lava all around looks more like the stuff I loved in Maui than something that's been around for 20,000 years. It looks all black and sharp and fresh!
I hadn't realized that the area was so geologically active. I understood (or thought I understood) plate tectonics, but I didn't realize that even the plates are full of lots of separate blocks. It turns out the Sierras and the White-Inyos were on separate rising blocks, and the Owens Valley was on a falling block. The Owens Valley bedrock is nearly 5,000 feet below sea level -- the current floor of the valley is formed by debris from the surrounding mountains!
After a okay night in Lone Pine (I went to bed early, feeling a bit sick), we headed out to see some evidence of this. We checked out a 20-foot scarp formed by the earthquake of 1872. It was kind of amazing to think of the earth actually moving that much -- no wonder lots of people in Lone Pine died in this 7.something monster!
Then we headed out to the Alabama Hills -- these look just like the granite outcroppings in Joshua Tree. B. and I scrambled up on top of one while M. (my SO) looked around at birds. Yow, definitely fun and amazing stuff.
We headed up a creek bed to check out some gigantic glacial moraines, and then headed up the valley and into the White-Inyos in search of one of B.'s favorite spots -- a rock outcropping with the Cambrian - PreCambrian border evident. Although we spent an hour or so wandering in the cold wind, we finally discovered that we were a bit to the south of the outcropping. It was all okay, though, as we got to wander through a radio-telescope array that was being erected up there. It was really amazing to see these 15-foot dishes still in their shipping containers, getting propped up onto fancy bases.
After a bit of driving around, we finally found the access road to the outcropping. Alas, it was a bit too rough for the minivan (although B. had earlier taken it down some amazing roads -- he clearly knows off-road driving!). We salved our disappointment with hummus and pita and other lunch goodies.
On the way down, B. spotted a tufa outcropping and pulled the van over. This was fun -- I'm so used to having a park service placard to tell me what I'm looking at, and here's a geologist out in the field just saying, "Check this out!" How cool! Tufa is formed in lake beds (it's currently forming in Mono Lake) when calcium-rich fresh water bubbles up into alkali lakes. It was amazing to actually see it poking out of the side of a hill a thousand feet up from the valley floor!
We eventually headed down and went up past Bishop to check out a gigantic, 15-mile wide volcanic caldera. This was formed in a gigantic explosion 750,000 years ago, spewing pink dust all over the west, where it formed rocks called Bishop Tuft. Wild.
We stopped off to check out the geothermally heated Warm Creek, but there was too much uncleared snow on the road. M. and B. took this opportunity to check out the snowshoes I'd brought along. B., especially, seemed to enjoy running around on the snow, hooting and hollering. Both of them were surprizingly good at using the gigantic snowshoes, which were sized for my 200-pound self!
We then headed up to Mono Lake and Panum Crater. Panum Crater is a relatively recent eruption (I think it is 600 years old), full of cool obsidian and all sorts of tortured piles of rock. After a cold hike around there, we headed for the tufa deposits on Mono Lake. This was equally cold, and since I'd seen this all just a few years before, I headed back to the van early, coughing up a storm. I had thought I was over my cold, but I guess not!
We headed back to Bishop for some good pizza and wine and a somewhat-pleasant night's sleep. In the morning, we checked out Bishop Creek, where B. found some good glacial moraines (formed from the rocks picked up by the glaciers as the carved their way through the Sierras in the last ice age). I got to check out the road to South Lake, where I camped and hiked with the WTC folks. It was still cold and snowy.
At this point, we dashed back home, as B. and M. had to prepare for classes on Monday. And I had to cough and hack a bit more.
Going through the Mojave was amazing. The flowers brought out lots of tiny bees (or maybe wasps), and they splattered all over the van as we drove through. At some points it sounded like rain. It is strange to see the desert come so alive -- I guess we ought to savor it, as this year's record rainfall probably won't be repeated again soon.
Anyway, it was a fabulous trip, and lots of fun. I recommend the geological field trip to Owens Valley to everyone. :-)