Continental Scientific Drilling -- The Cascades as a Target

Abstract

The Cascades volcanic arc should be a top national priority for research, particularly deep scientific drilling. Much of the world's geothermal and mineral resource base has formed as a direct result of magmatic activity associated with subduction related volcanic arcs. The Cascade Range is the only active subduction related volcanic arc in the conterminous United States. It is also on of the best known volcanic arcs in the world. Its great size, over 1300 km long, and high potential for geothermal resources underscore the economic importance o the Cascade arc to the nation. It is also of world wide significant, because it represents a unique end member in the spectrum of subduction related volcanic arcs. It is related to nearly aseismic subduction of a very small, very hot oceanic plate in the dying phases of the subduction process. Development of a comprehensive geologic model for eth Cascade arc, when combine with data from arcs related to rapid subduction of old oceanic lithosphere, will provide a general model for subduction related volcanic arcs throughout the world.