Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2488
Off-fault ground ruptures in the Santa Cruz Mountains, California: Ridge-top spreading versus tectonic extension during the 1989 Loma Prieta earthquake Off-fault ground ruptures in the Santa Cruz Mountains, California: Ridge-top spreading versus tectonic extension during the 1989 Loma Prieta earthquake
The Ms 7.1 Loma Prieta earthquake of 18 October 1989 produced abundant ground ruptures in an 8 by 4 km area along Summit Road and Skyland Ridge in the Santa Cruz Mountains. Predominantly extensional fissures formed a left-stepping, crudely en echelon pattern along ridges of the hanging-wall block southwest of the San Andreas fault, about 12 km northwest of the epicenter. The fissures are
Authors
Daniel J. Ponti, Ray E. Wells
Neogene rotations and quasicontinuous deformation of the Pacific Northwest continental margin Neogene rotations and quasicontinuous deformation of the Pacific Northwest continental margin
Paleomagnetically determined rotations about vertical axes of 15 to 12 Ma flows of the Miocene Columbia River Basalt Group of Oregon and Washington decrease smoothly with distance from the plate margin, consistent with a simple physical model for continental deformation that assumes the lithosphere behaves as a thin layer of fluid. The average rate of northward translation of the...
Authors
Philip England, Ray E. Wells
Amino acid dating of fossil mollusks Amino acid dating of fossil mollusks
No abstract available.
Authors
D.R. Muhs
Introduction to Special section on the California-Arizona crustal transect: Part I Introduction to Special section on the California-Arizona crustal transect: Part I
No abstract available.
Authors
Keith A. Howard, R.W. Simpson, G. B. Haxel
K-Ar and fission-track ages (dates) of volcanic, intrusive, altered, and metamorphic rocks in the Mohave Mountains area, west-central Arizona K-Ar and fission-track ages (dates) of volcanic, intrusive, altered, and metamorphic rocks in the Mohave Mountains area, west-central Arizona
No abstract available.
Authors
J. K. Nakata, M.A. Pernokas, Keith A. Howard, J.R. Shannon
Visibility of fault strands in exploratory trenches and timing of rupture events Visibility of fault strands in exploratory trenches and timing of rupture events
No abstract available.
Authors
M. G. Bonilla, James J. Lienkaemper
Introduction to special section on the California-Arizona crustal transect: Part II Introduction to special section on the California-Arizona crustal transect: Part II
In May 1988, a multidisciplinary conference was held in Flagstaff, Arizona, to synthesize recent research on the crustal structural and evolution of a transect across the southern Cordillera. This transect extends from the southern Colorado Plateau southwestward across the Arizona Transition Zone, through the Basin and Range province in the Mojave and Sonoran deserts, to the San Andreas...
Authors
G. B. Haxel, R.W. Simpson, Keith A. Howard
The 40Ar/39Ar thermochronology of the eastern Mojave Desert, California, and adjacent western Arizona with implications for the evolution of metamorphic core complexes The 40Ar/39Ar thermochronology of the eastern Mojave Desert, California, and adjacent western Arizona with implications for the evolution of metamorphic core complexes
Mesozoic thickening and Cenozoic extension resulted in the juxtaposition of upper and middle crustal rocks in the eastern Mojave Desert, southeastern California and western Arizona. The application of 40Ar/39Ar thermochronology to rocks in this region provides information about the timing and nature of thrusting, plutonism, metamorphism, denudation, and detachment faulting. The 40Ar/39Ar...
Authors
D.A. Foster, T.M. Harrison, C. F. Miller, Keith A. Howard
The Denali fault system and Alaska Range of Alaska: Evidence for underplated Mesozoic flysch from magnetotelluric surveys The Denali fault system and Alaska Range of Alaska: Evidence for underplated Mesozoic flysch from magnetotelluric surveys
Regional magnetotelluric surveys recently completed across the central and eastern Alaska Range of Alaska provide evidence for large volumes of conductive rocks beneath the core of the range. These conductive rocks may represent a formerly extensive, but now collapsed, Mesozoic flysch basin formed on the leading edge of the Talkeetna superterrane (amalgamated Wrangellia, Peninsular, and...
Authors
W. D. Stanley, Victor F. Labson, Warren J. Nokleberg, Bela Csejtey, M. A. Fisher
Rock movement and mass wastage in the Grand Canyon Rock movement and mass wastage in the Grand Canyon
No abstract available.
Authors
Richard Hereford, P. W. Huntoon
Geosciences Geosciences
No abstract available.
Authors
Roger D. Borcherdt, N. C. Donovan, D. Eberhart-Phillips, A. Michael, Paul A. Reasenberg, L. Dietz, W. Ellsworth, Daniel J. Ponti, Ray E. Wells, R. A. Haugerud, M. M. Clark, N. T. Hall
Physical and chemical properties of the phosphate deposit on Nauru, western equatorial Pacific Ocean Physical and chemical properties of the phosphate deposit on Nauru, western equatorial Pacific Ocean
No abstract available.
Authors
David Z. Piper, B.J. Loebner, P. Aharon