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Publications

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

Filter Total Items: 2354

Application of a feedforward neural network in the search for kuroko deposits in the Hokuroku District, Japan

A feedforward neural network with one hidden layer and five neurons was trained to recognize the distance to kuroko mineral deposits. Average amounts per hole of pyrite, sericite, and gypsum plus anhydrite as measured by X-rays in 69 drillholes were used to train the net. Drillholes near and between the Fukazawa, Furutobe, and Shakanai mines were used. The training data were selected carefully to
Authors
Donald A. Singer, Ryoichi Kouda

Status and metal content of significant metallic mineral deposits in the Pacific Northwest: A contribution to the Interior Columbia Basin Ecosystem Management Project

No abstract available.
Authors
Arthur A. Bookstrom, Michael L. Zientek, Stephen E. Box, Pamela D. Derkey, James E. Elliott, David Frishman, Roger P. Ashley, Russell C. Evarts, Douglas B. Stoeser, Lorre A. Moyer, Dennis P. Cox, Steve D. Ludington

The generation of oceanic rhyolites by crystal fractionation: the basalt-rhyolite association at Volcán Alcedo, Galápagos archipelago

Alcedo volcano is one of six shield volcanoes on Isabela Island in the western Galápagos Islands. Although Alcedo is dominantiy basaltic, it is unusual in that it also has erupted ∼1 km3 of rhyolite. The rhyolitic phase marked a 10-fold decrease in the mass-eruption rate of the volcano, and the volcano has returned to erupting basalt. The basalts are tholeiitic and range from strongly to sparsely
Authors
Dennis Geist, Keith A. Howard, Peter Larson

Rapid extension recorded by cooling‐age patterns and brittle deformation, Naxos, Greece

The metamorphic core complex exposed as the island of Naxos in the Aegean Sea records an unusually complete sequence of structures developed as a result of continental extension. The structures formed during Miocene rise and cooling from ductile, upper amphibolite facies and anatectic conditions to brittle near‐surface conditions beneath the Naxos detachment fault. Top‐to‐the‐north ductile fabrics
Authors
B.E. John, Keith A. Howard

Sources of the Early Cretaceous plutons in the Turtle and West Riverside Mountains, California

Ages and initial isotopic ratios of Early Cretaceous (˜100 Ma) plutons of the Cordilleran Interior in the southern Turtle and West Riverside mountains distinguish them from Late Cretaceous plutons in surrounding ranges in the eastern Mojave Desert. Furthermore, the studied plutons have isotopic and geochemical characteristics more similar to plutons of Cretaceous age in the coastal batholiths (Pen
Authors
C. M. Allen, J. L. Wooden, Keith A. Howard, D.A. Foster, R. M. Tosdal

The role of serpentinite melanges in the unroofing of UHPM rocks: An example from the Western Alps of Italy: Chapter 6

The ultrahigh pressure metamorphic rocks (UHPM) of the Dora-Maira continental massif are overlain by a stack of oceanic nappes. Metamorphic grade appears to increase downward but with marked discontinuities between each of the nappes, suggesting that section has been removed along the bounding faults. This apparent omission of section is greatest in the lowest oceanic unit where a serpentinite mel
Authors
M. Clark Blake, D.E. Moore, A. S. Jayko

Geochemical processes controlling acid-drainage generation and cyanide degradation at Summitville

No abstract available. 
Authors
Geoffrey S. Plumlee, Kathleen S. Smith, Elwin L. Mosier, Walter H. Ficklin, Maria R. Montour, Paul Briggs, Allen L. Meier

The importance of geology in understanding and remediating environmental problems at Summitville

No abstract available. 
Authors
Geoffrey S. Plumlee, John E. Gray, M. M. Roeber, Mark F. Coolbaugh, Marta J. Flohr, Gene Whitney

Hot-side-up aureole in southwest Yukon and limits on terrane assembly of the northern Canadian Cordillera: Comment and Reply

No abstract available.
Authors
V. L. Hansen, D.H. Oliver, Cynthia Dusel-Bacon, Stephen T. Johnston, Philippe Erdmer

Latest Quaternary foraminifers and sediment transport in Pervenets Canyon, Bering Sea

A combination of microfossil and sediment analysis has been used in an attempt to understand oceanographic processes and the late Quaternary history of the Pervenets Canyon region. The primary sedimentation process in Pervenets Canyon is downslope transport. Near the shelfbreak, there is evidence of turbidite and debris-flow activity, but at the distal end of the upper canyon and on the continenta
Authors
Scott W. Starratt