Publications Details

Research drilling in young silicic volcanoes

Eichelberger, J.C.

Magmatic activity, and particularly silicic magmatic activity, is the fundamental process by which continental crust forms and evolves. Drilling in the Inyo Chain, a 600-year-old chain of volcanic vents in California, has shown the close relationship of silicic eruption to shallow dike emplacement, the control of eruptive style by shallow porous-flow degassing, the origin of obsidian by welding, the development of igneous zonation by viscosity segregation, and the character and size of conduits in relation to well- understood magmatic and phreatic eruptions. Planned drilling at the site of the largest eruption of the century, in the Mt. Katmai region of Alaska, will test models for explosive eruptions, elucidate the process of vapor-transport of metals, and provide the first measurements of rates of cooling and chemical alteration in a relatively simple, non-composite igneous system. -Author