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Publications

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

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U–Pb geochronology of Late Cretaceous and early Tertiary plutons in the northern Coast Mountains batholith U–Pb geochronology of Late Cretaceous and early Tertiary plutons in the northern Coast Mountains batholith

U–Pb geochronologic studies demonstrate that steeply dipping, sheetlike tonalitic plutons along the western margin of the northern Coast Mountains batholith were emplaced between ~83 and ~57 (perhaps ~55) Ma. Less elongate tonalitic–granodioritic bodies in central portions of the batholith yield ages of 59–58 Ma, coeval with younger phases of the tonalitic sheets. Large granite...
Authors
G.E. Gehrels, W. C. McClelland, S.D. Sampson, Patchett P. Jonathan, David A. Brew

Application of the FINDER system to the search for epithermal vein gold-silver deposits : Kushikino, Japan, a case study Application of the FINDER system to the search for epithermal vein gold-silver deposits : Kushikino, Japan, a case study

The FINDER system employs geometric probability, Bayesian statistics, and the normal probability density function to integrate spatial and frequency information to produce a map of probabilities of target centers. Target centers can be mineral deposits, alteration associated with mineral deposits, or any other target that can be represented by a regular shape on a two dimensional map...
Authors
Donald A. Singer, Ryoichi Kouda

ALACARTE User Interface - AML Code and Demonstration Maps ALACARTE User Interface - AML Code and Demonstration Maps

ALACARTE offers a convenient way to compile geologic maps in the computer as spatial databases that can be used to prepare both cartographic images and analytic derivatives. It is a menu-controlled shell, organized in geologic terms, that provides on-screen control of the program ARC/INFO, a commercial geographic information system (GIS). Input can be from imported scans, digitizer...
Authors
Todd T. Fitzgibbon, Carl M. Wentworth

Factors affecting the recognition of faults exposed in exploratory trenches Factors affecting the recognition of faults exposed in exploratory trenches

Trenching-a widely used method for evaluating fault activity-has limitations that can mislead investigators. Some segments of fault strands in trench walls may not be visible, and this nonvisibility can lead to incorrect interpretations of time of most recent displacement and recurrence intervals on a fault. We examined the logs of 163 trench exposures and tabulated data on more than 1...
Authors
Manuel G. Bonilla, James J. Lienkaemper

ALACARTE installation and system manual ALACARTE installation and system manual

ALACARTE offers a convenient way to compile geologic maps in the computer as spatial databases that can be used to prepare both cartographic images and analytic derivatives. It is a menu-controlled shell, organized in geologic terms, that provides on-screen control of the program ARC/INFO, a commercial geographic information system (GIS). Input can be from imported scans, digitizer...
Authors
Todd T. Fitzgibbon

ALACARTE user manual ALACARTE user manual

ALACARTE offers a convenient way to compile geologic maps in the computer as spatial databases that can be used to prepare both cartographic images and analytic derivatives. It is a menu-controlled shell, organized in geologic terms, that provides on-screen control of the program ARC/INFO, a commercial geographic information system (GIS). Input can be from imported scans, digitizer...
Authors
Carl M. Wentworth, Todd T. Fitzgibbon
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