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Publications

Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center

Filter Total Items: 2339

Cenozoic plate motions and the volcano-tectonic evolution of western Oregon and Washington

A refined northeast Pacific plate-motion model provides a framework for analysis of the Tertiary volcanic and tectonic history of western Oregon and Washington. We examine three possible models for the origin of the allochthonous Paleocene and Eocene oceanic basalt basement of the Coast Range: (1) accretion to the continent of hot spot generated linear seamount chains; (2) accretion of thick ocean
Authors
Ray Wells, David C. Engebretson, P. D. Snavely, R. S. Coe

Shimada Seamount: An example of recent mid-plate volcanism

Shimada Seamount is an isolated volcanic feature located between the Clipperton and Clarion Fracture Zones ∼1,150 km west of the East Pacific Rise and ∼600 km west of the inactive spreading center represented by the Mathematician Seamounts. It rises ∼3,900 m above the surrounding sea floor to within 50 m of present-day sea level. The area of Shimada Seamount should be volcanically dormant, because
Authors
J. V. Gardner, Walter E. Dean, Richard J. Blakely

Geological Survey research, fiscal year 1981

A summary of recent significant scientific and economic results accompanied by a list of geologic, hydrologic, and cartographic investigations in progress.
Authors

Geomagnetic paleointensities from excursion sequences in lavas on Oahu, Hawaii

Paleomagnetic data demonstrating three late Tertiary excursions in the direction of the geomagnetic field recorded in sequences of basaltic lavas on the island of Oahu, Hawaii were published by R. R. Doell and G. B. Dalrymple in 1973. We have determined geomagnetic paleointensities by the Thelliers' method for 14 lavas from the three sites. During these experiments, considerable difficulty was enc
Authors
Robert S. Coe, Sherman Gromme, Edward A. Mankinen

Paleomagnetic constraints on the interpretation of early Cenozoic Pacific Northwest paleogeography

Widespread Cenozoic clockwise tectonic rotation in the Pacific Northwest is an established fact; however, the geologic reconstructions based on these rotations are the subject of continuing debate. Three basic mechanisms have been proposed to explain the rotations: (1) simple shear rotation of marginal terranes caught in the dextral shear couple between oceanic plates and North America; (2) rotati
Authors
Ray E. Wells

Implications of paleomagnetism for the tectonic history of the Eastern Klamath and related terranes in California and Oregon

Paleomagnetic study of Permian to Jurassic volcanic and sedimentary strata of the Eastern Klamath terrane has shown the remanent magnetism of these rocks to be prefolding and primary. The Permian and Triassic rocks are both indicated to have rotated 100° clockwise, while the Jurassic strata have rotated 60° clockwise. The respective amounts of rotation for Permian and Jurassic strata are similar a
Authors
Edward A. Mankinen, William P. Irwin, C. Sherman Grommé

Book review: Geomagnetism of baked clays and recent sediments

This book is an outgrowth of the symposium entitled “Time Scales of Geomagnetic Secular Variations,” which was held at the 4th Assembly of the International Association of Geomagnetism and Aeronomy (Edinburgh, U.K., August 1981). The volume includes many of the papers presented, which described paleomagnetic results from both archeologic materials and Holocene geologic deposits, as well as contrib
Authors
Edward A. Mankinen