After my time traveling adventure from last week, I was thinking of how lovely California was. I decided that I wanted to take a hike, and Washington just couldn't compete with California! So I hoped in my van and again headed south. Down I5 I went until I cut off East towards Bakersfield. From there I headed north east until I reached Death Valley. I decided to hike on the Ubehebe Crater Loop.
I reached the canyon edge and the picture above is what I saw. Since I have been dabbling in my spare time to reconstruct geologic maps of my adventures, I naturally had a few questions. First off, what the heck caused the crater? Was it a meteor impact? If so, are there glass fragments around from the heat effects of the meteor crashing into Earth? Or perhaps some shocked quartz from the explosion? I would have to know not only the geologic conditions inside the crater, but around the edges and surrounding area.
My next question was the type of sediment on the crater walls. I can see plenty of lateral continuity between the layers, the questions is, what type of layers are they? I see some vertical faults running perpendicular to the canyon floor, perhaps from water? The top layer looked especially interesting. It appears to be a completely different sediment than the layers underneath. Obviously something happened here recently based on the principle of superposition. Finally, I had the usual questions when dealing with a map, where precisely was the crater located, how deep was the crater, how wide was the crater, how steep were the canyon walls, and whether or not water pools here.
After arriving back home, I did some digging to find out about my crater. Turns out, there was nothing extraterrestrial about it, "Ubehebe Crater is a large volcanic crater" (NPS, 2014). So there we have it, a volcano! But wait, this doesn't look like a normal volcanic cone to me. Quickly I realized my naive error. I have studied volcanoes in my Geology class so I knew they came in all shapes and sizes. The question now became, how did this crater get created?
Turns out it was an explosion! Not an impact but and an outward explosion, and recently! I knew there was something suspicious about that top layer! Ubehebe Crater is only a 300 year old maar volcano, "Created by steam and gas explosions when hot magma rising up from the depths reached ground water" (NPS, 2014). Pretty cool, I don't know if I have read about a maar volcano yet. "The intense heat flashed the water into steam which expanded until the pressure was released as a tremendous explosion" (NPS, 2014). Interesting, sounds a lot like Mt. Saint Helens!
I also learned about the crater walls, "the colorful layers in the crater’s eastern wall are fanglomerates through which the explosion occurred. Fanglomerate is an alluvial fan deposit hardened into rock" (NPS, 2014). My question about water turned out to be a good one, "Water erosion created the deep gullies that you see on the crater’s east side. The pink and brown mud flat at the bottom of the crater is the site of many short-lived lakes" (NPS, 2014). My curiosity quenched, I set about to work on my geologic map of the Ubehebe Crater.
References:
National Park Service. (Aug 8th, 2014). Ubehebe Crater. Retrieved from https://www.nps.gov/deva/planyourvisit/ubehebe-crater.htm
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