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Publications

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

Filter Total Items: 2488

Implications of a magnetic model of the Long Valley caldera, California Implications of a magnetic model of the Long Valley caldera, California

A quantitative magnetic model of Long Valley, California, shows that the magnetic field above this caldera is dominated by intracaldera Bishop tuff, part of the ash flow tuff whose eruption precipitated the caldera collapse. We propose that about half of the 350 km3 of intracaldera Bishop tuff, or that part beneath the resurgent dome, has been subjected to extensive hydrothermal...
Authors
D.L. Williams, F. Berkman, Edward A. Mankinen

The area of influence of an exploratory hole The area of influence of an exploratory hole

A method is presented for calculating the area of influence of exploratory drill holes by using the size and shape of resource targets. The solution presented is for elliptical and circular targets, but the method is applicable to any shaped target. The degree to which points have been explored depends upon their distance away from a drill hole and the possible orientations of the target...
Authors
D.A. Singer, L. J. Drew

Natural remanent magnetization, mag¬netic properties, and oxidation of titanomagnetite in basaltic rocks from DSDP Leg 34 Natural remanent magnetization, mag¬netic properties, and oxidation of titanomagnetite in basaltic rocks from DSDP Leg 34

We have made paleomagnetic measurements and investigated the magnetic mineralogy of 24 samples of basalt and diabase from Sites 319, 320, and 321 on the Nazca plate. Sample distributions, locations, and ages of overlying sediments are as follows: Site 319, Hole 319, lat 13°01.04'S, long 101°31.46'W, 2 samples, early Miocene (N8); Site 319, Hole 319A, (same coordinates and age), 12...
Authors
C. Sherman Gromme, Edward A. Mankinen

Chino Valley formation (Cambrian?) in northwestern Arizona Chino Valley formation (Cambrian?) in northwestern Arizona

A thin persistent unit (maximum thickness 13 m) of probable Cambrian age in the Chino Valley region of northwestern Arizona consists of three laterally equivalent, mutually exclusive lithofacies. These are, from west to east, lithic sandstone, pebble to boulder conglomerate, and dolomite. The unit, named the Chino Valley Formation, is younger than middle Middle Cambrian and older than...
Authors
Richard Hereford
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