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We are engaged in field, geochronologic, geochemical, and theoretical studies of Silicic Magmatism and Volcanology--studying the life histories of the crustal magma bodies that give rise to large, explosive eruptions that spread ash continent-wide. Therefore, we map young silicic volcanic systems, do radiometric dating of lavas and tuffs, and determine the chemical and isotopic compositions of the volcanic products as clues to their origin and evolution. In other cases we study the guts of ancient volcanoes and the granitic bodies they leave below, exposed on the sides of mountain ranges, in order to better understand their plumbing systems. We work to understand how magmatism and regional-scale deformation of the continental crust interact, especially in extensional provinces. We also model the surface deformation that would be expected by intrusion of magma at depth and how volcanoes will respond to loading/unloading by movements of water and ice during glaciation/deglaciation intervals.
Courses Offered:
Gail Mahood's Personal Page |
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Photos, clockwise:
Mazama pumice fall deposits from Crater Lake, Oregon (Photo by Lee
Siebert, Smithsonian Institution) Postclassic Maya site of Mixco Viejo built on Quaternary ignimbrite in the highlands of Guatemala. Young ignimbrites filled valleys cut into older metamorphic rocks, creating the only flat surfaces in this mountainous area. These easily-eroded rocks were, in turn, incised by rivers, creating near-vertical cliffs that would impede attackers and make a site on top of the ignimbrite plateau highly defensible. The platforms and ballcourts are built of blocks of mica schist that had to be transported from the rivers below. The site is littered with fragments of rhyolitic obsidian. (Photo by Sid Carter) Pinatubo Caldera (Photo by Chris Newhall, USGS) 1980 Mt. St. Helens eruption column (Photo from USGS archives, 1981) Gail doing field work on the ignimbrite from the 1912 eruption of the Valley of Ten Thousand Smokes, Alaska. Obsidian incised with Mayan glyph, Guatemala (Photo by Sid Carter) |
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1st year of the Stanford Geological Survey | |||||||||||||||||||||||
Dogs and geology have a long tradition together at Stanford. Find out more about Gail's dogs. | |||||||||||||||||||||||
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updated March 23, 2006 | webmaster | ||||||||||||||||||||||