Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2477
Multi-geophysical parameter classification of the Montserrat geothermal system Multi-geophysical parameter classification of the Montserrat geothermal system
Multi-geophysical parameter classification can help to reduce the uncertainties of interpretations that often rely on one geophysical technique. Integrating these varying datasets requires a more robust classification approach rather than traditional qualitative methods. In this study, we applied the Fuzzy c-means (FCM) method to quantitatively classify similarities in a high resolution...
Authors
Racine A. Basant, Graham A. Ryan, Jared R. Peacock, Antonio G. Camacho, Oshaine O. Blake, Stefanie Hautmann, Bridget Y. Lynne
Porphyry and epithermal mineral deposits Porphyry and epithermal mineral deposits
Porphyry and epithermal mineral deposits form large economic ore bodies that provide the global economy with copper, molybdenum, gold, silver and other byproducts (Re, Te, Se). They form in the upper crust and are related to sulfur- and water-rich intermediate to silicic magmatic sources of hydrothermal fluids that move upward and produce extensive hydrolytic and alkali wall-rock...
Authors
John H Dilles, David A. John
Quantitative textural measures of the aeromagnetic field: Two examples at regional scale Quantitative textural measures of the aeromagnetic field: Two examples at regional scale
No abstract available.
Authors
Mark E. Gettings
Phasing of millennial-scale climate variability in the Pacific and Atlantic Oceans Phasing of millennial-scale climate variability in the Pacific and Atlantic Oceans
New radiocarbon and sedimentological results from the Gulf of Alaska document recurrent millennial-scale episodes of reorganized Pacific Ocean ventilation synchronous with rapid Cordilleran Ice Sheet discharge, indicating close coupling of ice-ocean dynamics spanning the past 42,000 years. Ventilation of the intermediate-depth North Pacific tracks strength of the Asian monsoon...
Authors
Maureen Walczak, Alan Mix, Ellen Cowan, Stewart Fallon, Keith Fitfield, Jay R. Alder, Jianghui Du, Brian Haley, Tim Hobern, June Padman, Summer K. Praetorius, Andreas Schmittner, Joseph Stoner, Sarah Zellers
Meeting the challenge: U.S. Geological Survey North Atlantic and Appalachian Region fiscal year 2020 in review Meeting the challenge: U.S. Geological Survey North Atlantic and Appalachian Region fiscal year 2020 in review
The utilization, preservation, and conservation of the Nation’s resources requires well-informed management decisions. The North Atlantic and Appalachian Region (NAAR) of the U.S. Geological Survey (USGS) supports science-based decision making for Federal, State, and local policymakers to meet the challenges of today and into the future. The science centers in the NAAR have well-deserved
Authors
By
Chesapeake Bay Activities, Florence Bascom Geoscience Center, Geology, Minerals, Energy, and Geophysics Science Center, Maryland-Delaware-D.C. Water Science Center, National Minerals Information Center, New England Water Science Center, New Jersey Water Science Center, New York Water Science Center, Ohio-Kentucky-Indiana Water Science Center, Pennsylvania Water Science Center, Virginia and West Virginia Water Science Center, Woods Hole Coastal and Marine Science Center, Office of Tribal Relations
Deglaciation of the Puget Lowland, Washington Deglaciation of the Puget Lowland, Washington
Recently obtained radiocarbon ages from the southern Puget Lowland and reevaluation of limiting ages from the Olympic Peninsula in the light of new light detection and ranging (LiDAR) data suggest that the Juan de Fuca and Puget lobes of the Cordilleran ice sheet reached their maximum extents after 16,000 calibrated yr B.P. Source areas for both lobes fed through a common conduit, likely...
Authors
Ralph A. Haugerud
Diverse cataclysmic floods from Pleistocene glacial Lake Missoula Diverse cataclysmic floods from Pleistocene glacial Lake Missoula
In late Wisconsin time, the Purcell Trench lobe of the Cordilleran ice sheet dammed the Clark Fork of the Columbia River in western Montana, creating glacial Lake Missoula. During part of this epoch, the Okanogan lobe also dammed the Columbia River downstream, creating glacial Lake Columbia in northeast Washington. Repeated failure of the Purcell Trench ice dam released glacial Lake...
Authors
Roger P. Denlinger, David L. George, Charles M. Cannon, Jim E. O'Connor, Richard B. Waitt
The nature and composition of the J-M Reef, Stillwater Complex, Montana, USA The nature and composition of the J-M Reef, Stillwater Complex, Montana, USA
In this contribution, we analyze 30 years of mine development data and quantitatively identify the processes that control the grade and tenor of the mineralized rock. An assay database of more than 60,000 samples was used to examine variations in ore grade and tenor of the sulfide mineralization in the J-M reef horizon of the Stillwater Complex along the strike and down the dip of the...
Authors
Michael Jenkins, James E. Mungall, Michael L. Zientek, Paul Holick, Kevin Butak
Getting to the root of plant‐mediated methane emissions and oxidation in a thermokarst bog Getting to the root of plant‐mediated methane emissions and oxidation in a thermokarst bog
Vascular plants are important in the wetland methane cycle, but their effect on production, oxidation, and transport has high uncertainty, limiting our ability to predict emissions. In a permafrost‐thaw bog in Interior Alaska, we used plant manipulation treatments, field‐deployed planar optical oxygen sensors, direct measurements of methane oxidation, and microbial DNA analyses to...
Authors
Jesse C Turner, Colby J Moorberg, Andrea Wong, Kathleen Shea, Mark Waldrop, Merritt R. Turetsky, Rebecca B. Neumann
Remote thermal detection of exfoliation sheet deformation Remote thermal detection of exfoliation sheet deformation
A growing body of research indicates that rock slope failures, particularly from exfoliating cliffs, are promoted by rock deformations induced by daily temperature cycles. Although previous research has described how these deformations occur, full three-dimensional monitoring of both the deformations and the associated temperature changes has not yet been performed. Here we use...
Authors
Antoine Guerin, Michel Jaboyedoff, Brian D. Collins, Greg M. Stock, Marc-Henri Derron, Antonio Abellan, Battista Matasci
Linking mesoscale meteorology with extreme landscape response: Effects of narrow cold frontal rainbands (NCFR) Linking mesoscale meteorology with extreme landscape response: Effects of narrow cold frontal rainbands (NCFR)
Landscapes evolve in response to prolonged and/or intense precipitation resulting from atmospheric processes at various spatial and temporal scales. Whereas synoptic (large‐scale) features (e.g., atmospheric rivers and hurricanes) govern regional‐scale hydrologic hazards such as widespread flooding, mesoscale features such as thunderstorms or squall lines are more likely to trigger...
Authors
Brian D. Collins, N. S. Oakley, Jonathan P. Perkins, Amy E. East, Skye C. Corbett, Benjamin J. Hatchett
A multiproxy database of western North American Holocene paleoclimate records A multiproxy database of western North American Holocene paleoclimate records
Holocene climate reconstructions are useful for understanding the diverse features and spatial heterogeneity of past and future climate change. Here we present a database of western North American Holocene paleoclimate records. The database gathers paleoclimate time series from 184 terrestrial and marine sites, including 381 individual proxy records. The records span at least 4000 of the...
Authors
Cody C. Routson, Darrell S. Kaufman, Nicholas P. McKay, Michael Erb, S. H. Arcusa, Kendrick Brown, Matthew E. Kirby, Jeremiah Marsicek, R. Scott Anderson, Gonzalo Jimenez-Moreno, Jessica R. Rodysill, M. S. Lachniet, Sherilyn C. Fritz, Joseph Bennett, Michelle F. Goman, Sarah E. Metcalfe, J. M. Galloway, G. Schoups, David Wahl, Jesse L. Morris, F. Staines-Urias, A. Dawson, B. N. Shuman, Daniel G. Gavin, Jeffrey S. Munroe, Brian F. Cumming