Premium
Neogene tectonics and kinematics of western North America
Author(s) -
Walcott Dick
Publication year - 1993
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1029/92tc02249
Subject(s) - geology , subduction , neogene , seismology , clockwise , paleontology , craton , north american plate , paleomagnetism , tectonics , plate tectonics , lithosphere , basin and range province , triple junction , peninsula , structural basin , oceanography , rotation (mathematics) , history , geometry , mathematics , archaeology
Recent quantitative studies of deformation in western North America including Pacific and North American relative plate motion, estimates of Neogene displacement in the southern Basin and Range, and anomalous paleomagnetic declinations of the Pacific Northwest are self‐consistent and, together, determine a simple kinematic model of the deformation that is an extension of the 1970 plate tectonic model of Atwater. A large continental lithospheric block, called here the Sierra Nevada/Klamath block, was displaced about 300 km to the W‐NW relative to the North American craton during the Neogene. The southern end of the overriding plate in the subduction zone along the Pacific Northwest has been shifted the same amount, resulting in the subduction zone and overlying accretionary complex rotating clockwise about 30°. The pivot is located near Seattle and the several tens of kilometers of N‐S shortening required to accommodate the rotation is taken up in the major thrusts of the Juan de Fuca Strait and Olympic Peninsula.