Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2532
Geese mediate vegetation state changes with parallel effects on N cycling that leave nutritional legacies for offspring Geese mediate vegetation state changes with parallel effects on N cycling that leave nutritional legacies for offspring
Along the coastal fringe of the Yukon–Kuskokwim River Delta in southwestern Alaska, geese maintain grazing lawns dominated by a rhizomatous sedge that, when ungrazed, transitions to a taller, less palatable growth form that is taxonomically described as a different species. Nutrients recycled in goose feces, in conjunction with grazing, are critical to the rapid, nutritious growth of...
Authors
Roger W. Ruess, Jack McFarland, Brian T. Person, James S. Sedinger
Controls on eolian landscape evolution in fractured bedrock Controls on eolian landscape evolution in fractured bedrock
Wind abrasion is important for planetary landscape evolution, and wind‐abraded bedrock landscapes contain many landforms that are difficult to interpret. Here we exploit a natural experiment in Chile where topographic shielding by an upwind lava flow yields diverse erosional landforms in a downwind ignimbrite. Using a 3‐D topographic wind model, we find that low velocities in the wake of...
Authors
Jonathan P. Perkins, Noah J. Finnegan, Shanaka L. de Silva, Michael J. Willis
Insights into post-Miocene uplift of the western margin of the Colorado Plateau from the stratigraphic record of the lower Colorado River Insights into post-Miocene uplift of the western margin of the Colorado Plateau from the stratigraphic record of the lower Colorado River
The spatial and temporal distribution of Pliocene to Holocene Colorado River deposits (southwestern USA and northwestern Mexico) form a primary data set that records the evolution of a continental-scale river system and helps to delineate and quantify the magnitude of regional deformation. We focus in particular on the age and distribution of ancestral Colorado River deposits from field
Authors
Ryan S. Crow, Keith A. Howard, L. Sue Beard, Phil Pearthree, Kyle House, Karl Karlstrom, Lisa Peters, William C. McIntosh, Colleen Cassidy, Tracey J. Felger, Debra Block
Detrital zircon geochronology along a structural transect across the Kahiltna assemblage in the western Alaska Range: Implications for emplacement of the Alexander-Wrangellia-Peninsular terrane against North America Detrital zircon geochronology along a structural transect across the Kahiltna assemblage in the western Alaska Range: Implications for emplacement of the Alexander-Wrangellia-Peninsular terrane against North America
The Kahiltna assemblage in the western Alaska Range consists of deformed Upper Jurassic and Cretaceous clastic strata that lie between the Alexander-Wrangellia-Peninsular (AWP) terrane to the south, and the Farewell and other peri-cratonic terranes to the north. Differences in detrital zircon populations and sandstone petrography allow geographic separation of the strata into two...
Authors
Stephen E. Box, Susan M. Karl, James V. Jones, Dwight Bradley, Peter J. Haeussler, Paul B. O’Sullivan
Large loss of CO2 in winter observed across pan-arctic permafrost region Large loss of CO2 in winter observed across pan-arctic permafrost region
Recent warming in the Arctic, which has been amplified during the winter1,2,3, greatly enhances microbial decomposition of soil organic matter and subsequent release of carbon dioxide (CO2)4. However, the amount of CO2 released in winter is not known and has not been well represented by ecosystem models or empirically based estimates5,6. Here we synthesize regional in situ observations...
Authors
Susan M Natali, Jennifer D. Watts, Stefano Potter, Brendan M. Rogers, Sarah M. Ludwig, Anne-Katrin Selbmann, Patrick F. Sullivan, Benjamin W. Abbott, Kyle A. Arndt, Leah Birch, Mats P. Bjorkman, Anthony Bloom, Gerardo Celis, Torben R. Christiensen, Casper T. Christiansen, Roisin Commane, Elisabeth J. Cooper, Patrick Crill, Claudia Czimczik, Sergey Davydov, Jinyang Du, Jocelyn E. Egan, Bo Elberling, Eugenie S. Euskirchen, Thomas Friborg, Helene Genet, Mathias Gockede, Jordan P. Goodrich, Paul Grogan, Manuel Helbig, Elchin E. Jafarov, Julie Jastrow, Aram Kalhori, Yongwon Kim, John S Kimball, Lars Kutzbach, Mark J. Lara, Klaus S. Larsen, Michael M Loranty, Magnus Lund, Massimo Lupascu, Nima Madani, Avni Malhorta, Jack McFarland, David A. McGuire, Anders Michelson, Christina Minions, Walter C. Oechel, David Olefeldt, Frans-Jan Parmentier, Norbert Pirk, Benjamin Poulter, William L. Quinton, Fereidoun Rezanezhad, David Risk, Torsten Sachs, Kevin Schaefer, Neils M. Schmidt, Edward A. Schuur, Philipp R. Semenchuk, Gaius Shaver, Oliver Sonnentag, Gregory Starr, Claire C. Treat, Mark P. Waldrop, Yihui Wang, Jeffrey Welker, Christian Wille, Xiaofeng Xu, Zhen Zhang, Qianlai Zhuang, Donatella Zona
Geology and assessment of undiscovered oil and gas resources of the East Greenland Rift Basins Province, 2008 Geology and assessment of undiscovered oil and gas resources of the East Greenland Rift Basins Province, 2008
In 2007 the U.S. Geological Survey (USGS) completed an assessment of undiscovered, technically recoverable oil and gas resources in the East Greenland Rift Basins Province of Northeast Greenland. The province was selected as the prototype for the U.S. Geological Survey Circum-Arctic Resource Appraisal (CARA). In collaboration with the Geological Survey of Denmark and Greenland (GEUS)...
Authors
Donald L. Gautier
Geology of the Monte Blanco borate deposits, Furnace Creek Wash, Death Valley, California Geology of the Monte Blanco borate deposits, Furnace Creek Wash, Death Valley, California
The Monte Blanco borate deposits are located along the southern margin of Death Valley’s Furnace Creek Wash, south of Twenty Mule Team Canyon road in California. Topographic and geologic mapping by S. Muessig and F.M. Byers, Jr., in 1954 documented these deposits’ geologic settings, geometries, mineralogies, and chemical characteristics. They estimated borate resources at the time to be...
Authors
S.J. Muessig, W.M. Pennell, Jeffrey R. Knott, James P. Calzia
Can geologic factors be predictive for distinguishing between productive and non-productive geothermal wells? Can geologic factors be predictive for distinguishing between productive and non-productive geothermal wells?
Geologic data are examined to evaluate whether certain geologic characteristics occur in higher abundance or higher magnitude along production geothermal wells relative to non-productive wells. We perform 3D geologic mapping, 3D stress modeling, and fault-slip modeling to estimate fourteen different geologic factors that are hypothesized to control or correlate with well productivity...
Authors
Drew L. Siler, Erick R. Burns, James E Faulds
Discovering blind geothermal systems in the Great Basin Region: An integrated geologic and geophysical approach for establishing geothermal play fairways: All phases Discovering blind geothermal systems in the Great Basin Region: An integrated geologic and geophysical approach for establishing geothermal play fairways: All phases
Most geothermal resources in the Great Basin region of the western USA are blind, and thus the discovery of new commercial-grade systems requires synthesis of favorable characteristics for geothermal activity. The geothermal play fairway concept involves integration of multiple parameters indicative of geothermal activity to identify promising areas for new development. This project...
Authors
E. Faulds James, Nicholas H. Hinz, Mark Coolbaugh, Bridget Ayling, Jonathan M.G. Glen, Jason W. Craig, Emma McConnville, Drew L. Siler, John Queen, Jeff Witter, Christian Hardwick
Where’s the rock: Using convolutional neural networks to improve land cover classification Where’s the rock: Using convolutional neural networks to improve land cover classification
While machine learning techniques have been increasingly applied to land cover classification problems, these techniques have not focused on separating exposed bare rock from soil covered areas. Therefore, we built a convolutional neural network (CNN) to differentiate exposed bare rock (rock) from soil cover (other). We made a training dataset by mapping exposed rock at eight test sites...
Authors
Helen Petlyak, Corina Cerovski-Darriau, Vadim Zaliva, Jonathan D. Stock
Apatite trace element geochemistry and cathodoluminescent textures—Acomparison between regional magmatism and the Pea Ridge IOA-REE andBoss IOCG deposits, southeastern Missouri iron metallogenic province, USA Apatite trace element geochemistry and cathodoluminescent textures—Acomparison between regional magmatism and the Pea Ridge IOA-REE andBoss IOCG deposits, southeastern Missouri iron metallogenic province, USA
The southeast Missouri iron metallogenic province contains a remarkable wealth of historically important Fe, Cu, Au, and rare earth element (REE) deposits including the Pea Ridge iron oxide-apatite-rare earth element (IOA-REE) deposit and the Boss iron oxide-copper-gold (IOCG) deposit. These deposits are coeval with silicic and intermediate composition magmatism in the St. Francois...
Authors
Celestine N. Mercer, Kathryn E. Watts, Juliane Gross
Detection of rock bridges by infrared thermal imaging and modeling Detection of rock bridges by infrared thermal imaging and modeling
Characterization of rock discontinuities and rock bridges is required to define stability conditions of fractured rock masses in both natural and engineered environments. Although remote sensing methods for mapping discontinuities have improved in recent years, remote detection of intact rock bridges on cliff faces remains challenging, with their existence typically confirmed only after...
Authors
Antoine Guerin, Michel Jaboyefoff, Brian D. Collins, Marc-Henri Derron, Greg M. Stock, Battista Matasci, Martin Boesiger, Caroline Lefeuvre, Yury Y. Podladchikov