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Publications

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

Filter Total Items: 2542

Paleomagnetism and geology of Eocene volcanic rocks of southwest Washington, implications for mechanisms of tectonic rotation Paleomagnetism and geology of Eocene volcanic rocks of southwest Washington, implications for mechanisms of tectonic rotation

Paleomagnetic and geologic investigations in Eocene volcanic rocks of the southwest Washington Coast Range demonstrate a close relationship between tectonic rotations and the local structural geology. The allochthonous middle Eocene submarine basalt basement of the Crescent Formation consists of several fault‐bounded structural domains up to 30 km across that are characterized by...
Authors
Ray E. Wells, Robert S. Coe

Petrology and tectonic significance of augen gneiss from a belt of Mississippian granitoids in the Yukon-Tanana terrane, east- central Alaska Petrology and tectonic significance of augen gneiss from a belt of Mississippian granitoids in the Yukon-Tanana terrane, east- central Alaska

An approximately E-W-trending belt of porphyritic peraluminous granitic rocks, metamorphosed and deformed to augen gneiss, is exposed for 400 km across the Yukon-Tanana terrain. Chemical, textural, and isotopic data from large augen-gneiss bodies indicate that these bodies originated as early Mississippian granitic rocks that assimilated, or were anatectically derived from, early...
Authors
Cynthia Dusel-Bacon, John N. Aleinikoff

Well bore breakouts and in situ stress Well bore breakouts and in situ stress

The detailed cross-sectional shape of stress induced well bore breakouts has been studied using specially processed ultrasonic borehole televiewer data. Breakout shapes are shown for a variety of rock types and introduce a simple elastic failure model which explains many features of the observations. Both the observations and calculations indicate that the breakouts define relatively...
Authors
Mark D. Zoback, Daniel Moos, Larry Mastin, Roger N. Anderson

Canyon-filling lavas and lava dams on the Boise River, Idaho, and their significance for evaluating downcutting during the last 2 million years Canyon-filling lavas and lava dams on the Boise River, Idaho, and their significance for evaluating downcutting during the last 2 million years

Basalts that periodically dammed the Boise River and its South Fork over the last 2 million years reveal the canyon history and illustrate how lava interacted with impounded river water. Intracanyon basalt flows record a granite canyon successively filled by lava and then recut at least five times in the last 2 million years. The most voluminous flow, Steamboat Rock Basalt, reached 60...
Authors
Keith A. Howard, John W. Shervais, E.H. McKee

Statistical relations among earthquake magnitude, surface rupture length, and surface fault displacement Statistical relations among earthquake magnitude, surface rupture length, and surface fault displacement

In order to refine correlations of surface-wave magnitude, fault rupture length at the ground surface, and fault displacement at the surface by including the uncertainties in these variables, the existing data were critically reviewed and a new data base was compiled. Earthquake magnitudes were redetermined as necessary to make them as consistent as possible with the Gutenberg methods...
Authors
Manuel G. Bonilla, Robert K. Mark, James J. Lienkaemper
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