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Publications

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

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Devonian rocks of the Yukon-Porcupine Rivers area and their tectonic relation to other Devonian sequences in Alaska Devonian rocks of the Yukon-Porcupine Rivers area and their tectonic relation to other Devonian sequences in Alaska

Devonian rocks along the Yukon River near the Alaska-Yukon boundary comprise 250 feet of limestone and shale and 800 feet of chert and siliceous shale, all referred to the McCann Hill Chert of Early to Late Devonian age; about 3,000 feet of non-marine chert-pebble conglomerate, graywacke, and shale of the Nation River Formation (Late Devonian); and about 3,000 feet of an unnamed chert...
Authors
Michael Churkin, Earl E. Brabb

Post-paleozoic radiometric ages and their relevance to fault movements, Northern Southeastern Alaska Post-paleozoic radiometric ages and their relevance to fault movements, Northern Southeastern Alaska

Recently determined lead-alpha and potassium-argon ages from northern southeastern Alaska indicate major plutonic events in the Paleozoic, Mesozoic, and Tertiary; in contrast, previous studies suggested that only one complex Jurassic and Cretaceous event occurred. The ages presented in this paper indicate the following Mesozoic and Tertiary plutonic events: Middle or Late Jurassic (144...
Authors
R. A. Loney, David A. Brew, Marvin A. Lanphere

Historic surface faulting in continental United States and adjacent parts of Mexico Historic surface faulting in continental United States and adjacent parts of Mexico

This report summarizes geometric aspects of approximately 35 instances of historic faulting of the ground surface in the continental United States and adjacent parts of Mexico. This information is of immediate importance in the selection and evaluation of sites for vital structures such as nuclear power plants. The data are presented in a table and graphs which show the quantitative...
Authors
M. G. Bonilla

Magnetotelluric soundings in the southwestern United States Magnetotelluric soundings in the southwestern United States

Twelve magnetotelluric soundings were made along a 460-mile traverse in the southwestern United States. Spectral analysis of digitized graphic records was used to determine apparent resistivities and phase differences for periods in the range 10-1,000 sec. The geoelectric section to depths of the order of 300 km was found to be divided into three principal layers. The layer nearest the...
Authors
Donald Plouff

Ordovician, Silurian, and Devonian biostratigraphy of east-central Alaska Ordovician, Silurian, and Devonian biostratigraphy of east-central Alaska

A predominantly shale and chert sequence has been mapped from the Canadian border at Latitude 65°00′ N. to the Nation River about 25 miles northwest. It has Ordovician and Silurian graptolites in the lower half, and Middle Devonian corals and Upper Devonian spores in the upper half. The lower half of the sequence consists of about 400 to 900 feet of predominantly dark gray graptolitic...
Authors
Michael Churkin, Earl E. Brabb

Geological Survey research, 1965, Chapter D Geological Survey research, 1965, Chapter D

Scientific notes and summaries of investigations by members of the Conservation, Geologic, and Water Resources Divisions tn geology, hydrology, and related fields.
Authors
Water Resources Division U.S. Geological Survey
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