Saturday, July 11, 2009

Sample collecting: Henry's Mountains

I spent Monday night out in the BYU-Idaho Natural Science Center cabin in Island Park (North of Rexburg near West Yellowstone). Tuesday morning, I headed out with 3 other students to collect samples from flows of Basaltic Andesite from the Henry's Mountains which we'll use for a research project this fall. Brother Dan Moore led our group. We'll process the samples we collected at BYU in Provo this summer before school starts again in the fall.
Bro. Moore, our brilliant instructor:
Bro. Moore and Sam Grover
Fresh and weathered surfaces. Notice the pyroxene phenocrysts. They weather out into nice euhedral samples. Some of the soil on the ridge was full of them.
Our location (on a geologic map):
After we finished our collecting, we went up past Henry's Lake to the nearby Quake Lake in Montana and viewed the site of a significant landslide. Mass wasting to the extreme:

Monday, July 6, 2009

Craters of the Moon, National Monument

On the way back from my weekend in Boise, we stopped at Craters of the Moon, National Monument. Craters of the moon is an extensive series of basalt flows produced by a fissure eruption -part of the Snake River Plain volcanics. The flow is fairly recent, in a geological sense: 8 eruptive events over the past 15,000 years. The basalt flows of Craters of the Moon differ from other extrusive snake rvier plain volcanics in compositional and textural variety. It's an impressive sight -especially as you drive through and realize the extent of the flows (It's quite large).