title: Mantle-derived peridotites in southwestern Oregon: relation to plate tectonics.
abstract: A group of peridotites in southwestern Oregon contains high-pressure mineral assemblages reflecting recrystallization at high temperatures (1100 degrees to 1200 degrees C) over a range of pressure decreasing from 19 to 5 kilobars. It is proposed that the peridotites represent upper-mantle material brought from depth along the ancestral Gorda-Juan de Fuca ridge system, transported eastward by the spreading Gorda lithosphere plate, and then emplaced by thrust-faulting in the western margin of the Cordillera during late Mesozoic time.
authors.forename: L G
authors.initials: LG
authors.lastname: Medaris
authors.forename: R H
authors.initials: RH
authors.lastname: Dott