Publications
Browse recent USGS publications related to energy resources.
Filter Total Items: 2852
New evidence for polyphase metamorphism of glaucophane schist and eclogite exotic blocks in the Franciscan Complex, California and Oregon New evidence for polyphase metamorphism of glaucophane schist and eclogite exotic blocks in the Franciscan Complex, California and Oregon
The early metamorphic history of high-grade exotic blocks in the Franciscan Complex may be more complicated than previously supposed. The different assemblages of high-grade glaucophane schists, eclogite, amphibolite and hornblende schist are commonly considered to have formed at the same time from essentially unmetamorphosed oceanic crust. However, new textural and mineralogical data...
Authors
Diane E. Moore, M.C. Blake
Deformation of the Eastern Franciscan Belt, northern California Deformation of the Eastern Franciscan Belt, northern California
The late Jurassic and Cretaceous Eastern Franciscan belt of the northern California Coast Range consists of two multiply deformed, blueschist-facies terranes; the Pickett Peak and Yolla Bolly terranes. Four deformations have been recognized in the Pickett Peak terrane, and three in the Yolla Bolly terrane. The earliest recognized penetrative fabric, D1, occurs only in the Pickett Peak...
Authors
A. S. Jayko, M.C. Blake
Geologic map and structure sections of the Laurel 7-1/2ʹ quadrangle, Santa Clara and Santa Cruz Counties, California Geologic map and structure sections of the Laurel 7-1/2ʹ quadrangle, Santa Clara and Santa Cruz Counties, California
No abstract available.
Authors
J. C. Clark, E. E. Brabb, R. J. McLaughlin
Pb isotopic evidence for the formation of Proterozoic crust in the southwestern United States Pb isotopic evidence for the formation of Proterozoic crust in the southwestern United States
No abstract available.
Authors
J. L. Wooden, J. S. Stacey, Keith A. Howard, B. R. Doe, D. M. Miller
Minimum earthquake magnitude associated with coseismic surface faulting Minimum earthquake magnitude associated with coseismic surface faulting
No abstract available.
Authors
Manuel G. Bonilla
New and revised lithostratigraphic units from the southwestern New England Fold Belt New and revised lithostratigraphic units from the southwestern New England Fold Belt
New and revised lithostratigraphic units are recognized in northern New South Wales. New lithostatigraphic units are: Cara Formation, Whitlow Formation, Bobs Creek Formation, Nangahrah Formation, and Dinoga Formation. Revision of the Woolomin beds to Woolomin Group and Woodsreef Melange is proposed.
Authors
M. Clark Blake, B. Murchey
Metamorphic and tectonic evolution of the Franciscan Complex, northern California: Chapter 38 Metamorphic and tectonic evolution of the Franciscan Complex, northern California: Chapter 38
No abstract available.
Authors
M. Clark Blake, A. S. Jayko, R. J. McLaughlin, M.B. Underwood
Reconnaissance geologic map of the Pilot Creek Quadrangle, Humboldt and Trinity counties, California Reconnaissance geologic map of the Pilot Creek Quadrangle, Humboldt and Trinity counties, California
No abstract available.
Authors
K. R. Aalto, William Porter Irwin, H.M. Kelsey
Geologic map and structure sections of the Loma Prieta 7 1/2' quadrangle, Santa Clara and Santa Cruz Counties, California Geologic map and structure sections of the Loma Prieta 7 1/2' quadrangle, Santa Clara and Santa Cruz Counties, California
No abstract available.
Authors
Robert J. McLaughlin, Joseph C. Clark, Earl E. Brabb
A guide to commonly used map projections prepared for use in HyperCard, 1988 A guide to commonly used map projections prepared for use in HyperCard, 1988
This guide briefly describes and illustrates the characteristics of 17 map projections commonly used to present thematic data. By means of simple sketches of the basic grid system of longitude and latitude known as the Earth's graticule, the guide shows examples of the following categories of map projections: planes (azimuthal), cones, cylinders, and miscellaneous. The text gives...
Authors
Tau Rho Alpha, Joe F. Vigil, Lauren Buchholz
Models of grades and tonnages of some lode tin deposits Models of grades and tonnages of some lode tin deposits
Descriptive and grade/tonnage models have recently been built for many types of deposits. Such models consist of descriptions of mineralogy, host rocks, ore textures, controls, alteration, geochemical signatures, age, and tectonic settings, together with statistical models of grades, tonnages, and contained metal of deposits of each type. The models are used to identify areas that may...
Authors
W. D. Menzie, B.L. Reed, Donald A. Singer
The relative contribution of accretion, shear, and extension to Cenozoic tectonic rotation in the Pacific Northwest The relative contribution of accretion, shear, and extension to Cenozoic tectonic rotation in the Pacific Northwest
Large Cenozoic clockwise rotations defined by paleomagnetic data are an established fact in the Pacific Northwest, and many tectonic models have been proposed to explain them, including (1) rotation of accreted oceanic microplates during docking, (2) dextral shear between North America and northward-moving oceanic plates to the west, and (3) microplate rotation in front of an expanding...
Authors
Ray E. Wells, Paul L. Heller