Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2488
Major chemical characteristics of Mesozoic Coast Range ophiolite in California Major chemical characteristics of Mesozoic Coast Range ophiolite in California
Sixty-four major element analyses of rocks representative of the Coast Range ophiolite in California were compared with analyses of other onland ophiolite sequences and those of rocks from oceanic ridges. The rocks can be classed in five groups harzburgite-dunite, clinopyroxenite-wehrlite, gabbro, basalt-spilite, and keratophyre-quartz keratophyre which on various diagrams occupy...
Authors
E. H. Bailey, Blake
Fresh lunar impact craters: Review of variations in size Fresh lunar impact craters: Review of variations in size
Thirty-three morphologic characteristics are reviewed for fresh lunar impact craters wide than1 km. Bar graphs express the way each characteristic varies with crater size. The features are grouped as crater structure, ejecta, and downhill flow features. Major structural transition occur at diameters of about 15 and 200 km. Details of the ejecta blanket, which include several kinds of...
Authors
Keith A. Howard
Lunar basin formation and highland stratigraphy Lunar basin formation and highland stratigraphy
Multiring impact basins, formed after solidification of the lunar crust, account for most or all premare regional deposits and structures expressed in the lunar landscape and for major topographic and gravity variations. A fresh basin has two or more concentric mountain rings, a lineated ejecta blanket, and secondary impact craters. Crackled material on the floor may be impact melt. The...
Authors
Keith A. Howard, D.E. Wilhelms, D. H. Scott
Origin of Franciscan melanges in Northern California Origin of Franciscan melanges in Northern California
In northern California, chaotic Franciscan melange occurs beneath the overlying ophiolite and Great Valley Sequence. Identical melanges occur to the west, separating well-bedded, coherent Franciscan units that differ markedly in age. Detailed studies in several places indicate that these melanges mark the boundaries of imbricate thrust sheets, and they appear to occur at several discrete
Authors
M. Clark Blake, D. L. Jones
Gravity anomalies in the Galapagos Islands area Gravity anomalies in the Galapagos Islands area
No abstract available.
Authors
Anthony B. Watts, J. R. Cochran, J. E. Case, S. L. Ryland, Tom Simkin, Keith A. Howard
Geologic sketch of the Klamath Mountains and Coast Ranges of northern California and southern Oregon Geologic sketch of the Klamath Mountains and Coast Ranges of northern California and southern Oregon
No abstract available.
Authors
W. P. Irwin, E.W. Wolfe, M.C. Blake, C.G. Cunningham
Report on Circum-Pacific Energy and Mineral Resources Conferences Report on Circum-Pacific Energy and Mineral Resources Conferences
No abstract available.
Authors
M.T. Halbouty, J.F. Mason, E. E. Brabb
K-Ar Age Relations of Granodiorite Emplacement and Tungsten and Gold Mineralization near the Getchell Mine, Humboldt County, Nevada K-Ar Age Relations of Granodiorite Emplacement and Tungsten and Gold Mineralization near the Getchell Mine, Humboldt County, Nevada
A granodiorite stock intrudes complexly folded and thrust-faulted Paleozoic sedimentary rocks in the Osgood Mountains of eastern Humboldt County, Nevada. Within the metamorphic aureole surrounding the pluton, the sedimentary rocks are converted to cordierite hornfels and marble; tungsten-bearing tactites developed along the contacts of the granodiorite. Cutting the granodiorite and...
Authors
Miles L. Silberman, B. R. Berger, Randolph A. Koski
Spring mudflows at Wrightwood, Southern California Spring mudflows at Wrightwood, Southern California
The Wrightwood area in the San Gabriel Mountains of southern California is known as a site of recurring mudflow activity. The community of Wrightwood is built on the coalesced fans of Sheep, Acorn and Heath Creeks, and the fan deposits are probably chiefly of mudflow origin. Historically, mudflows there have been observed in association with three climatic conditions: (1) short period of...
Authors
D. M. Morton, R. H. Campbell
Preparation and use of isopleth maps of landslide deposits Preparation and use of isopleth maps of landslide deposits
Isopleth maps derived from landslide inventory maps generalize and quantify the areal distribution of landslide deposits in contour form and may be uniquely useful for some types of regional planning. The isopleth format permits incorporation of landslide information with other quantified map data in the preparation of slope stability maps. The isopleth map of landslide deposits in San...
Authors
Robert H. Wright, Russell H. Campbell, Tor H. Nilsen
Alaska Alaska
No abstract available.
Authors
E. H. Lathram, Arthur Grantz, D.F. Barnes, David A. Brew, A. Thomas Ovenshine, George Plafker, R. L. Detterman, H.L. Foster, M. Churkin, W. W. Patton, J. M. Hoare, I.L. Tailleur, W. P. Brosge, T. P. Miller, C.L. Sainsbury
Geologic map of the Pickett Peak quadrangle, Trinity County, California Geologic map of the Pickett Peak quadrangle, Trinity County, California
No abstract available.
Authors
William P. Irwin, M. Clark Blake, C. G. Cunningham