Structural evolution of the Columbia Plateau in Washington and Oregon ( USA).

Abstract

Columbia River Basalt flows were extruded episodically between 17-6Ma BP. Geophysical properties define a unique Columbia Plateau crustal unit N of the Columbia Arc. Deformation styles differed on either side of the Columbia Arc during plateau evolution. Deformation of the Columbia Plateau produced a wide range of structural styles and orientations during 3 tectonic stages. The 3 stages of deformation in the Columbia Plateau may be correlted with changing tectonic patterns at the W margin of the N American plate.-from Authors