Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2495
Post 12 m.y. rotation of southwest Washington Post 12 m.y. rotation of southwest Washington
Paleomagnetic field directions from the basalt of Pack Sack Lookout are compared to those from the Pomona Member of the Saddle Mountains Basalt of the Columbia River Basalt Group. The Pomona crops out over a wide region on the Columbia Plateau east of the Cascade Range, and the basalt of Pack Sack Lookout crops out well to the west of the Cascades about 30 to 60 km east of the Washington...
Authors
James R. Magill, Ray E. Wells, Robert W. Simpson, Allan Cox
Preliminary geologic map of Tecoma and Lucin quadrangles, Box Elder County, Utah, and Elko County, Nevada Preliminary geologic map of Tecoma and Lucin quadrangles, Box Elder County, Utah, and Elko County, Nevada
No abstract available.
Authors
David M. Miller, Joel D. Schneyer
Tectonic accretion of the Klamath Mountains Tectonic accretion of the Klamath Mountains
No abstract available.
Authors
W. P. Irwin
A geologic reconnaissance of the Cycladic blueschist belt, Greece A geologic reconnaissance of the Cycladic blueschist belt, Greece
The Cycladic blueschist belt consists of two distinctive segments separated by a broad zone of superposed granitic and high-temperature metamorphic rocks. The northern segment contains early metamorphic fold axes and parallel glaucophane lineations that trend ∼060° with a progressive increase in metamorphism toward the southeast. The southern segment contains similar fold axes and...
Authors
M. Clark Blake, Michel Bonneau, Jacques Geyssant, J.R. Kienast, Claude Lepvrier, Henri Maluski, Dimitrios Papanikolaou
Mid-Cretaceous radiolarians in Perapedhi Formation Mid-Cretaceous radiolarians in Perapedhi Formation
No abstract available.
Authors
W. P. Irwin, B.L. Murchey, D. L. Jones, S.A. Kling
Geology of a subduction complex in the Franciscan assemblage of northern California Geology of a subduction complex in the Franciscan assemblage of northern California
No abstract available.
Authors
M. Clark Blake, A. S. Jayko, D. G. Howell
Seismic zonation in the San Francisco Bay region Seismic zonation in the San Francisco Bay region
No abstract available.
Authors
E. E. Brabb
In the southwest: Tectonic evolution reviewed In the southwest: Tectonic evolution reviewed
No abstract available.
Authors
D. M. Miller, Keith A. Howard, M. D. Carr
Geologic transect of the northern Diablo Range, California Geologic transect of the northern Diablo Range, California
No abstract available.
Authors
M. Clark Blake
Proterozoic zircon from augen gneiss, Yukon-Tanana Upland, east-central Alaska Proterozoic zircon from augen gneiss, Yukon-Tanana Upland, east-central Alaska
U-Th-Pb analyses of zircons from an ortho-augen gneiss body in the Yukon-Tanana Upland of east-central Alaska yield strong evidence for the presence of early Proterozoic material in this area. U-Pb data define a chord that intersects concordia at about 2,300 and 345 m.y. We consider two interpretations: (1) the protolith was intruded during the Proterozoic and was subsequently...
Authors
John N. Aleinikoff, Cynthia Dusel-Bacon, Helen L. Foster, Kiyoto Futa
Geologic setting, petrology, and geochemistry of zoned tungsten-bearing skarns at the Strawberry Mine, central Sierra Nevada, California Geologic setting, petrology, and geochemistry of zoned tungsten-bearing skarns at the Strawberry Mine, central Sierra Nevada, California
The Strawberry mine, 90 km northeast of Fresno, California, occurs on the margin of a small roof pendant of Early Jurassic metasedimentary rocks and middle Cretaceous metaigneous rocks. Middle Cretaceous granitic intrusions surround and intrude the roof pendant. Adjacent to one granodiorite intrusion, several subvertical marble layers are replaced by scheelite-bearing skarns. The skarns...
Authors
Warren J. Nokleberg