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Science and Products
Geologic map of the central Beaverhead Mountains, Lemhi County, Idaho, and Beaverhead County, Montana
This geologic map of the central Beaverhead Mountains portrays a complex geologic history of depositional basin development interspersed with deformational events. Generalized geology for young basins, compiled from sources on both sides of the range, is combined with newly mapped bedrock geology to better integrate geologic development of the map...Lund, Karen
Two-event lode-ore deposition at Butte, USA: 40Ar/39Ar and U-Pb documentation of Ag-Au-polymetallic lodes overprinted by younger stockwork Cu-Mo ores and penecontemporaneous Cu lodes
The ore-genesis model for world-class deposits of the Butte mining district, Montana, USA, is deep pre-Main Stage porphyry Cu-Mo and overlying Main Stage Ag-Zn-Cu zoned-lode deposits, both of which formed from hydrothermal fluids driven by minor volumes of rhyolitic magma. The lode-specific model is that hydrothermal processes diminished in...Lund, Karen; McAleer, Ryan J.; Aleinikoff, John N.; Cosca, Michael A.; Kunk, Michael J.
Review of the geochemistry and metallogeny of approximately 1.4 Ga granitoid intrusions of the conterminous United States
The conterminous United States hosts numerous volumetrically significant and geographically dispersed granitoid intrusions that range in age from 1.50 to 1.32 billion years before present (Ga). Although previously referred to as A-type granites, most are better described as ferroan granites. These granitoid intrusions are distributed in the...du Bray, Edward A.; Holm-Denoma, Christopher S.; Lund, Karen; Premo, Wayne R.
Locatable mineral assessment tracts for the U.S. Geological Survey Sagebrush Mineral-Resource Assessment Project
The polygon (vector) feature class represents locatable mineral resource assessment tracts (tracts of land) associated with the Department of the Interior (DOI) Sagebrush Focal Areas (SFAs) in Montana, Wyoming and Utah, central Idaho, and the Oregon-Nevada-Idaho border area. The mineral-resources tracts are geographic areas that were assessed by...San Juan, Carma A.; Horton, John D.; Parks, Heather L.; Mihalasky, Mark J.; Anderson, Eric D.; Benson, Mary Ellen; Box, Stephen E.; Cossette, Pamela M.; Denning, Paul D.; Giles, Stuart A.; Hall, Susan M.; Hayes, Timothy S.; Hearn, Carter B.; Hofstra, Albert H.; John, David A.; Ludington, Stephen; Lund, Karen; Mauk, Jeffrey L.; Robinson, Gilpin R.; Rockwell, Barnaby W.; Rytuba, James J.; Smith, Steven M.; Stillings, Lisa; Van Gosen, Bradley S.; Vikre, Peter G.; Wallis, John C.; Wilson, Anna B.; Zientek, Michael L.; Zurcher, Lukas
Geology and mineral resources of the North-Central Idaho Sagebrush Focal Area: Chapter C in Mineral resources of the Sagebrush Focal Areas of Idaho, Montana, Nevada, Oregon, Utah, and Wyoming
SummaryThe U.S. Department of the Interior has proposed to withdraw approximately 10 million acres of Federal lands from mineral entry (subject to valid existing rights) from 12 million acres of lands defined as Sagebrush Focal Areas (SFAs) in Idaho, Montana, Nevada, Oregon, Utah, and Wyoming (for further discussion on the lands involved see...Lund, Karen; Zürcher, Lukas; Hofstra, Albert H.; Van Gosen, Bradley S.; Benson, Mary Ellen; Box, Stephen E.; Anderson, Eric D.; Bleiwas, Donald I.; DeAngelo, Jacob; Drake, Ronald M.; Fernette, Gregory L.; Giles, Stuart A.; Glen, Jonathan M. G.; Haacke, Jon E.; Horton, John D.; John, David A.; Robinson, Gilpin R.; Rockwell, Barnaby W.; San Juan, Carma A.; Shaffer, Brian N.; Smith, Steven M.; Williams, Colin F.
Geochemical, modal, and geochronologic data for 1.4 Ga A-type granitoid intrusions of the conterminous United States
Introduction The purpose of this report is to present available geochemical, modal, and geochronologic data for approximately 1.4 billion year (Ga) A-type granitoid intrusions of the United States and to make those data available to ongoing petrogenetic investigations of these rocks. A-type granites, as originally defined by Loiselle and Wones (...du Bray, Edward A.; Holm-Denoma, Christopher S.; San Juan, Carma A.; Lund, Karen; Premo, Wayne R.; DeWitt, Ed
SHRIMP U–Pb and REE data pertaining to the origins of xenotime in Belt Supergroup rocks: evidence for ages of deposition, hydrothermal alteration, and metamorphism
The Belt–Purcell Supergroup, northern Idaho, western Montana, and southern British Columbia, is a thick succession of Mesoproterozoic sedimentary rocks with an age range of about 1470–1400 Ma. Stratigraphic layers within several sedimentary units were sampled to apply the new technique of U–Pb dating of xenotime that sometimes forms as rims on...Aleinikoff, John N.; Lund, Karen; Fanning, C. Mark
Basement domain map of the conterminous United States and Alaska
The basement-domain map is a compilation of basement domains in the conterminous United States and Alaska designed to be used at 1:5,000,000-scale, particularly as a base layer for national-scale mineral resource assessments. Seventy-seven basement domains are represented as eighty-three polygons on the map. The domains are based on...Lund, Karen; Box, Stephen E.; Holm-Denoma, Christopher S.; San Juan, Carma A.; Blakely, Richard J.; Saltus, Richard W.; Anderson, Eric D.; DeWitt, Ed
Hells Canyon to the Bitterroot front: A transect from the accretionary margin eastward across the Idaho batholith
This field guide covers geology across north-central Idaho from the Snake River in the west across the Bitterroot Mountains to the east to near Missoula, Montana. The regional geology includes a much-modified Mesozoic accretionary boundary along the western side of Idaho across which allochthonous Permian to Cretaceous arc complexes of the Blue...Lewis, Reed S.; Smith, Keegan L.; Gaschnig, Richard M.; LaMaskin, Todd A.; Lund, Karen; Gray, Keith D.; Tikoff, Basil; Stetson-Lee, Tor; Moore, Nicholas
Descriptive and geoenvironmental model for Co-Cu-Au deposits in metasedimentary rocks: Chapter G in Mineral deposit models for resource assessment
Introduction This report is a revised model for a specific type of cobalt-copper-gold (Co-Cu-Au) deposit that will be evaluated in the next U.S. Geological Survey (USGS) assessment of undiscovered mineral resources in the United States (see Ferrero and others, 2012). Emphasis is on providing an up-to-date deposit model that includes both geologic...Slack, John F.; Slack, John F.; Johnson, Craig A.; Causey, J. Douglas; Lund, Karen; Schulz, Klaus J.; Gray, John E.; Eppinger, Robert G.
Constraints on the timing of Co-Cu ± Au mineralization in the Blackbird district, Idaho, using SHRIMP U-Pb ages of monazite and xenotime plus zircon ages of related Mesoproterozoic orthogneisses and metasedimentary rocks
The Blackbird district, east-central Idaho, contains the largest known Co reserves in the United States. The origin of strata-hosted Co-Cu ± Au mineralization at Blackbird has been a matter of controversy for decades. In order to differentiate among possible genetic models for the deposits, including various combinations of volcanic, sedimentary,...Aleinikoff, John N.; Slack, John F.; Lund, Karen; Evans, Karl V.; Fanning, C. Mark; Mazdab, Frank K.; Wooden, Joseph L.; Pillers, Renee M.
Synthesis of petrographic, geochemical, and isotopic data for the Boulder batholith, southwest Montana
The Late Cretaceous Boulder batholith in southwest Montana consists of the Butte Granite and a group of associated smaller intrusions emplaced into Mesoproterozoic to Mesozoic sedimentary rocks and into the Late Cretaceous Elkhorn Mountains Volcanics. The Boulder batholith is dominated by the voluminous Butte Granite, which is surrounded by as...du Bray, Edward A.; Aleinikoff, John N.; Lund, Karen