This morning, we drove into the town of Trona, CA to the Searles Valley Minerals mining and refinement facilities. Soda ash which is sodium carbonate, borax, and potash are mined from the vast supplies at this plant. By vast, I mean that some of the materials could continue to be mined for 1,800 years at the current rate! The upper salt, which is the top layer that contains the minerals, is about 80 feet deep. A man by the name of Jim Fairchild who had worked at the mine for 50 years gave us a presentation and a driving tour. The Searle Valley is pretty much the only home in the world to hanksite, a six sided crystal that is of the composition Na22K(SO4)9(CO3)2Cl We stopped and were able to collect large hanksite crystals in addition to many halite as well. Here is a picture of a few hanksite crystals:
We were also able to view the processing plant. The company is very strong on recycling energy and waste. They reuse heat, process carbon dioxide from burning fossil fuels, and return brine back to the lake. Here is a picture of the percolation pond with the mountains in the distance:
And here is a picture of the halite where the water level has actually reached the surface of the lake:
After lunch, we headed about 6 bumpy miles to the Trona Pinnacles of Searles Lake. On our drive, Sam Bowring, a top geology professor at MIT, started quizzing me about how the pinnacles were formed. After much reference to our terrascope-provided guidebooks, I provided many answers. Upon our arrival, he told me to go stand on a rock and tell everyone else what I had learned! Instead of our usual lecture from Sam, I was telling people that the pinnacles were made of tufa, which is a deposit of
calcium carbonate and organic material. The algae in the lake lowered the carbon dioxide concentration in the water, which would have precipitated the calcium carbonate. The pinacles formed for a similar reason that coral builds in the ocean based on varying sea levels. Many movies on Mars were filmed at this site. On the site, it was interesting to view a google earth image of the pinnacles to hypothesize about how and why they were laid down. The geologists guessed that they were on top of old fault lines where geothermal springs had popped up because each set was fairly linear. Learning and studying about the earth seems so fascinating out here with all the rare examples of geology right in front of yours eyes! Here are a few pictures of the pinnacles. See the people in the photos for comparative size.
Finally, on our drive to our hotel in the Mojave Desert, we saw a huge wind farm. This was particularly cool for me because I learned about wind power a few weeks ago in 1.007, Engineering for Environment and Sustainability and had visited a wind turbine blade testing facility. See literally hundreds of wind turbines in real life was amazing (although this word has lost meaning). Here is a picture from inside the car, although this is only a piece of the entire wind farm,