Wednesday, June 24, 2009

Field Camp, Part 2: Yellowstone NP

The igneous geology portion of field camp naturally brought us to Yellowstone National Park, one of the largest 'supervolcanoes' on earth. Yellowstone is a bimodal volcanic center, and erupts both felsic (Feldspar/Silica rich) Rhyolitic lava and mafic (Magnesium/Iron rich) Basaltic lava. Yellowstone National Park is situated within several nested calderas; each of these calderas formed after an eruption. The shallow (5km deep) magma chamber lost so much magma during each eruption that the earth's crust above the chamber collapses into the void. The caldera has since been filled with lava flows. The fractures and faults within the caldera allows for the incredible hydrothermal features within the park to occur.
Professor Colin Shaw explaining the classification scheme for igneous rocks using the infamous tertiary diagram.

Upper Yellowstone Falls.

Fountain Paint Pots, easily my favorite feature in the entire park.

Another paint pot.

Old Faithful Geyser, in the Upper Geyser Basin.

Lecturing at the Duck Lake overlook, the site of a huge hydrothermal explosion. Duck Lake is the explosion crater, and has a ring shaped hill around it, which is the ejecta blanket.

Mud volcano! Similar to the paint pots in several regards. The mud cinder cone here used to be over 40' high if I remember correctly.

No comments: