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The Idaho cobalt belt The Idaho cobalt belt

The Idaho cobalt belt (ICB) is a northwest-trending belt of cobalt (Co) +/- copper (Cu)-bearing deposits and prospects in the Salmon River Mountains of east-central Idaho, U.S.A. The ICB is about 55 km long and 10 km long in its central part, which contains multiple strata-bound ore zones in the Blackbird mine area. The Black Pine and Iron Creek Co-Cu prospects are southeast of Blackbird...
Authors
Arthur A. Bookstrom

Paleogeographic insights based on new U-Pb dates for altered tuffs in the Miocene Barstow Formation, California Paleogeographic insights based on new U-Pb dates for altered tuffs in the Miocene Barstow Formation, California

The type section of the Barstow Formation in the Mud Hills, north of Barstow, is a reference section for early to middle Miocene paleontology, magnetostratigraphy, and dated volcanic episodes. Thanks to this robust chronologic framework, much of the interpretation of the paleogeography of the region from about 18 Ma to 13 Ma is based on study of the rocks in the Mud Hills. Eastward from...
Authors
David M. Miller, Jose E. Rosario, Shannon R. Leslie, Jorge A. Vazquez

Monte Carlo simulations of product distributions and contained metal estimates Monte Carlo simulations of product distributions and contained metal estimates

Estimation of product distributions of two factors was simulated by conventional Monte Carlo techniques using factor distributions that were independent (uncorrelated). Several simulations using uniform distributions of factors show that the product distribution has a central peak approximately centered at the product of the medians of the factor distributions. Factor distributions that...
Authors
Mark E. Gettings

Stratigraphy and paleogeographic significance of the Pennsylvanian-Permian Bird Spring Formation in the Ship Mountains, southeastern California Stratigraphy and paleogeographic significance of the Pennsylvanian-Permian Bird Spring Formation in the Ship Mountains, southeastern California

A thick sequence of limestone, dolomite, and minor sandstone assigned to the Pennsylvanian and lower Permian Bird Spring Formation is exposed in the Ship Mountains about 85 kilometers (km) southwest of Needles, California, in the eastern Mojave Desert. These strata provide a valuable reference section of the Bird Spring Formation in a region where rocks of this age are not extensively...
Authors
Paul Stone, Calvin H. Stevens, Keith A. Howard, Thomas D. Hoisch

Hysteresis of unsaturated hydromechanical properties of a silty soil Hysteresis of unsaturated hydromechanical properties of a silty soil

Laboratory tests to examine hysteresis in the hydrologic and mechanical properties of partially saturated soils were conducted on six intact specimens collected from a landslide-prone area of Alameda County, California. The results reveal that the pore-size distribution parameter remains statistically unchanged between the wetting and drying paths; however, the wetting or drying state...
Authors
Ning Lu, Murat Kaya, Brian D. Collins, Jonathan W. Godt

Basin thickness variations at the Junction of the Eastern California Shear Zone and the San Bernardino Mountains, California: How thick could the Pliocene sections be? Basin thickness variations at the Junction of the Eastern California Shear Zone and the San Bernardino Mountains, California: How thick could the Pliocene sections be?

We estimate the thickness of Neogene basin fill along the junction of the Eastern California Shear Zone and the North Frontal thrust system of the San Bernardino Mountains using gravity data with geologic and well log constraints. The geometry of the basin fill is of interest for groundwater assessment and location of potential faults, as well as providing an upper bound on the thickness...
Authors
Victoria E. Langenheim, Tammy L. Surko, Phillip A. Armstrong, Jonathan C. Matti

Dzhezkazgan and associated sandstone copper deposits of the Chu-Sarysu basin, Central Kazakhstan Dzhezkazgan and associated sandstone copper deposits of the Chu-Sarysu basin, Central Kazakhstan

Sandstone-hosted copper (sandstone Cu) deposits occur within a 200-km reach of the northern Chu-Sarysu basin of central Kazakhstan (Dzhezkazgan and Zhaman-Aibat deposits, and the Zhilandy group of deposits). The deposits consist of Cu sulfide minerals as intergranular cement and grain replacement in 10 ore-bearing members of sandstone and conglomerate within a 600- to 1,000-m thick...
Authors
Stephen E. Box, Reimar Seltmann, Michael L. Zientek, Boris Syusyura, Robert A. Creaser, Alla Dolgopolova

Vegetation, substrate, and eolian sediment transport at Teesto Wash, Navajo Nation, 2009-2012 Vegetation, substrate, and eolian sediment transport at Teesto Wash, Navajo Nation, 2009-2012

On the Navajo Nation, southwestern United States, warming temperatures and recent drought have increased eolian (windblown) sediment mobility such that large, migrating sand dunes affect grazing lands, housing, and road access. We present an assessment of seasonal variations in sand transport, mobility, and ground cover (vegetation and substrate) within a 0.2-km2 study area near Teesto...
Authors
Amy E. Draut, Margaret Hiza Redsteer, Lee Amoroso

Regional geophysical expression of a carbonatite terrane in the eastern Mojave Desert, California Regional geophysical expression of a carbonatite terrane in the eastern Mojave Desert, California

A world-class, rare earth element carbonatite deposit is located near Mountain Pass, in the eastern Mojave Desert of California and is hosted by Proterozoic rocks that extend along the eastern margins of the Clark Mountain Range, Mescal Range, and Ivanpah Mountains in a north-northwest trending fault-bounded block. This Proterozoic block is generally composed of a complex of 1.7 - 1.6 Ga...
Authors
David A. Ponce, Kevin M. Denton, David M. Miller

Digital geologic map of the Redding 1° x 2° quadrangle, Shasta, Tehama, Humboldt, and Trinity Counties, California Digital geologic map of the Redding 1° x 2° quadrangle, Shasta, Tehama, Humboldt, and Trinity Counties, California

The Redding 1° x 2° quadrangle in northwestern California transects the Franciscan Complex and southern Klamath Mountains province as well as parts of the Great Valley Complex, northern Great Valley, and southernmost Cascades volcanic province. The tectonostratigraphic terranes of the Klamath province represent slices of oceanic crust, island arcs, and overlying sediment that range...
Authors
Luis A. Fraticelli, John P. Albers, William P. Irwin, Milton C. Blake, Carl M. Wentworth
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