Garth E Graham
Garth Graham is a Research Geologist with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Filter Total Items: 34
Timing of ore-related magmatism in the western Alaska Range, southwestern Alaska
This report presents isotopic age data from mineralized granitic plutons in an area of the Alaska Range located approximately 200 kilometers to the west-northwest of Anchorage in southwestern Alaska. Uranium-lead isotopic data and trace element concentrations of zircons were determined for 12 samples encompassing eight plutonic bodies ranging in age from approximately 76 to 57.4 millions...
Authors
Ryan D. Taylor, Garth E. Graham, Eric D. Anderson, David Selby
Tectonic evolution and Cretaceous gold metallogenesis of southwestern Alaska
Cretaceous gold metallogenesis in southwestern Alaska comprises three distinct episodes related to the accretionary evolution of northwestern North America. The oldest mineralizing event is characterized by 112 Ma Cu-Au-Bi-Te porphyry-type(?) veining in the zoned Bonanza and adjacent plutons that intruded rocks of the Nyac terrane. Tectonic reconstructions and limited geological and...
Authors
Garth E. Graham, Richard J. Goldfarb, Marti L. Miller, Kati Gibler, Mike Roberts
Geologic setting, sedimentary architecture, and paragenesis of the Mesoproterozoic sediment-hosted Sheep Creek Cu-Co-Ag deposit, Helena embayment, Montana
The northern margin of the Helena Embayment contains extensive syngenetic to diagenetic massive pyrite horizons that extend over 25 km along the Volcano Valley-Buttress fault zone and extend up to 8 km basinward (south) within the Mesoproterozoic Newland Formation. The Sheep Creek Cu-Co deposit occurs within a structural block along a bend in the fault system, where replacement-style...
Authors
Garth E. Graham, Murray W. Hitzman, Jerry Zieg
Investigation of the potential for concealed base-metal mineralization at the Drenchwater Creek Zn-Pb-Ag occurrence, northern Alaska, using geology, reconnaissance geochemistry, and airborne electromagnetic geophysics
In 2005, the U.S. Geological Survey, Bureau of Land Management, and State of Alaska cooperated on an investigation of the mineral potential of a southern part of the National Petroleum Reserve in Alaska, Howard Pass quadrangle, to provide background information for future land-use decisions. The investigation incorporated an airborne electromagnetic (EM) survey covering 1,500 mi2 (~3,900...
Authors
Garth E. Graham, Maria Deszcz-Pan, Jared E. Abraham, Karen D. Kelley
Trace elements in Zn Pb Ag deposits and related stream sediments, Brooks Range Alaska, with implications for Tl as a pathfinder element
The Zn-Pb-Ag metallogenic province of the western and central Brooks Range, Alaska, contains two distinct but mineralogically similar deposit types: shale-hosted massive sulphide (SHMS) and smaller vein-breccia occurrences. Recent investigations of the Red Dog and Anarraaq SHMS deposits demonstrated that these deposits are characterized by high trace-element concentrations of As, Ge, Sb...
Authors
G.E. Graham, Karen D. Kelley, J. R. Slack, Alan E. Koenig
The Drenchwater deposit, Alaska: An example of a natural low pH environment resulting from weathering of an undisturbed shale-hosted Zn-Pb-Ag deposit
The Drenchwater shale-hosted Zn-Pb-Ag deposit and the immediate vicinity, on the northern flank of the Brooks Range in north-central Alaska, is an ideal example of a naturally low pH system. The two drainages, Drenchwater and False Wager Creeks, which bound the deposit, differ in their acidity and metal contents. Moderately acidic waters with elevated concentrations of metals (pH ??? 4.3...
Authors
G.E. Graham, Karen D. Kelley
Filter Total Items: 15
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Science and Products
Filter Total Items: 34
Timing of ore-related magmatism in the western Alaska Range, southwestern Alaska
This report presents isotopic age data from mineralized granitic plutons in an area of the Alaska Range located approximately 200 kilometers to the west-northwest of Anchorage in southwestern Alaska. Uranium-lead isotopic data and trace element concentrations of zircons were determined for 12 samples encompassing eight plutonic bodies ranging in age from approximately 76 to 57.4 millions...
Authors
Ryan D. Taylor, Garth E. Graham, Eric D. Anderson, David Selby
Tectonic evolution and Cretaceous gold metallogenesis of southwestern Alaska
Cretaceous gold metallogenesis in southwestern Alaska comprises three distinct episodes related to the accretionary evolution of northwestern North America. The oldest mineralizing event is characterized by 112 Ma Cu-Au-Bi-Te porphyry-type(?) veining in the zoned Bonanza and adjacent plutons that intruded rocks of the Nyac terrane. Tectonic reconstructions and limited geological and...
Authors
Garth E. Graham, Richard J. Goldfarb, Marti L. Miller, Kati Gibler, Mike Roberts
Geologic setting, sedimentary architecture, and paragenesis of the Mesoproterozoic sediment-hosted Sheep Creek Cu-Co-Ag deposit, Helena embayment, Montana
The northern margin of the Helena Embayment contains extensive syngenetic to diagenetic massive pyrite horizons that extend over 25 km along the Volcano Valley-Buttress fault zone and extend up to 8 km basinward (south) within the Mesoproterozoic Newland Formation. The Sheep Creek Cu-Co deposit occurs within a structural block along a bend in the fault system, where replacement-style...
Authors
Garth E. Graham, Murray W. Hitzman, Jerry Zieg
Investigation of the potential for concealed base-metal mineralization at the Drenchwater Creek Zn-Pb-Ag occurrence, northern Alaska, using geology, reconnaissance geochemistry, and airborne electromagnetic geophysics
In 2005, the U.S. Geological Survey, Bureau of Land Management, and State of Alaska cooperated on an investigation of the mineral potential of a southern part of the National Petroleum Reserve in Alaska, Howard Pass quadrangle, to provide background information for future land-use decisions. The investigation incorporated an airborne electromagnetic (EM) survey covering 1,500 mi2 (~3,900...
Authors
Garth E. Graham, Maria Deszcz-Pan, Jared E. Abraham, Karen D. Kelley
Trace elements in Zn Pb Ag deposits and related stream sediments, Brooks Range Alaska, with implications for Tl as a pathfinder element
The Zn-Pb-Ag metallogenic province of the western and central Brooks Range, Alaska, contains two distinct but mineralogically similar deposit types: shale-hosted massive sulphide (SHMS) and smaller vein-breccia occurrences. Recent investigations of the Red Dog and Anarraaq SHMS deposits demonstrated that these deposits are characterized by high trace-element concentrations of As, Ge, Sb...
Authors
G.E. Graham, Karen D. Kelley, J. R. Slack, Alan E. Koenig
The Drenchwater deposit, Alaska: An example of a natural low pH environment resulting from weathering of an undisturbed shale-hosted Zn-Pb-Ag deposit
The Drenchwater shale-hosted Zn-Pb-Ag deposit and the immediate vicinity, on the northern flank of the Brooks Range in north-central Alaska, is an ideal example of a naturally low pH system. The two drainages, Drenchwater and False Wager Creeks, which bound the deposit, differ in their acidity and metal contents. Moderately acidic waters with elevated concentrations of metals (pH ??? 4.3...
Authors
G.E. Graham, Karen D. Kelley
Filter Total Items: 15
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