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Publications

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

Filter Total Items: 2482

Marine magnetic anomalies Marine magnetic anomalies

Marine magnetic data have been available for many years from all of the world's oceans, and their contribution to marine geophysics and geology is profound. These data, for example, have allowed charting the age of the ocean floor, reconstruction of the geologic history of the major ocean basins, development of a Cenozoic and Mesozoic timescale of geomagnetic reversals, and speculation...
Authors
Richard J. Blakely, S.C. Cande

Assessing Metallic Resources in Alaska Assessing Metallic Resources in Alaska

In the last two decades federal and state governments have become in creasingly preoccupied with classi fying public lands according to the uses that may be made of them. One outcome of the classifying can be a change in the land's legal status from one in which any use is tolerated to one in which only selected activities are allowed. Since such a change af fects the economic and...
Authors
Donald A. Singer, A. Thomas Ovenshine

Geomagnetic paleointensities by the Thelliers' method from submarine pillow basalts: Effects of seafloor weathering Geomagnetic paleointensities by the Thelliers' method from submarine pillow basalts: Effects of seafloor weathering

Measurements of geomagnetic paleointensity using the Thelliers' double‐heating method in vacuum have been made on 10 specimens of submarine pillow basalt obtained from 7 fragments dredged from localities 700,000 years old or younger. In the magnetic minerals, the titanium/iron ratio parameter x and the cation deficiency (oxidation) parameter x were determined by X‐ray diffraction and...
Authors
Sherman Gromme, Edward A. Mankinen, Monte Marshall, Robert S. Coe

Revised geomagnetic polarity time scale for the interval 0–5 m.y. B.P. Revised geomagnetic polarity time scale for the interval 0–5 m.y. B.P.

A change in the constants used in K‐Ar dating and a significant increase in new data have made a recompilation and recomputation of data used to define the Late Cenozoic K‐Ar polarity time scale highly desirable at this time. All available data in the range 0–5 m.y. have been recalculated using the refined constants, with 354 data points in this time interval now meeting the minimum...
Authors
Edward A. Mankinen, G. Brent Dalrymple

Evidence for tectonic movement of the Las Positas Fault, Alameda County, California Evidence for tectonic movement of the Las Positas Fault, Alameda County, California

On October 29, 1979, a new exposure of the Las Positas fault zone near Livermore, California, was created by excavation of a creek bank along Arroyo Seco. The face of the bank was cleaned by geologists of Lawrence Livermore Laboratory (Livermore, California) to obtain a better and more complete view of the fault. The excavation was undertaken by Lawrence Livermore Laboratory as part of a...
Authors
Darrell G. Herd, Earl E. Brabb
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