Geology, Minerals, Energy, and Geophysics Science Center

Publications

Filter Total Items: 2,242
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Year Published: 2019

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...

Ruess, Roger W.; McFarland, Jack; Person, Brian T.; Sedinger, James S.

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Year Published: 2019

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,...

Perkins, Jonathan P; Finnegan, Noah J.; de Silva, Shanaka L.; Willis, Michael J.

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Year Published: 2019

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...

Crow, Ryan S.; Howard, Keith A.; Beard, L. Sue; Phil Pearthree; House, Kyle; Karlstrom, Karl; Lisa Peters; McIntosh, William C.; Cassidy, Colleen; Felger, Tracey J.; Block, Debra

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Year Published: 2019

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...

Box, Stephen E.; Karl, Susan M.; Jones, James V.; Bradley, Dwight C.; Haeussler, Peter; O'Sullivan, Paul B.

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Year Published: 2019

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...

Natali, Susan M; Watts, Jennifer D.; Potter, Stefano; Rogers, Brendan M.; Ludwig, Sarah M.; Selbmann, Anne-Katrin; Sullivan, Patrick F.; Abbott, Benjamin W.; Arndt, Kyle A.; Birch, Leah; Bjorkman, Mats P.; Bloom, Anthony; Celis, Gerardo; Christiensen, Torben R.; Christiansen, Casper T.; Commane, Roisin; Cooper, Elisabeth J.; Crill, Patrick; Czimczik, Claudia; Davydov, Sergey; Du, Jinyang; Egan, Jocelyn E.; Elberling, Bo; Euskirchen, Eugenie S.; Friborg, Thomas; Genet, Helene; Gockede, Mathias; Goodrich, Jordan P.; Grogan, Paul; Helbig, Manuel; Jafarov, Elchin E.; Jastrow, Julie; Kalhori, Aram A.M.; Kim, Yongwon; Kimball, John S; Kutzbach, Lars; Lara, Mark J.; Larsen, Klaus S.; Loranty, Michael M; Lund, Magnus; Lupascu, Massimo; Madani, Nima; Malhorta, Avni; McFarland, Jack; McGuire, David A.; Michelson, Anders; Minions, Christina; Oechel, Walter C.; Olefeldt, David; Parmentier, Frans-Jan; Pirk, Norbert; Poulter, Benjamin; Quinton, William L.; Rezanezhad, Fereidoun; Risk, David; Sachs, Torsten; Schaefer, Kevin; Schmidt, Neils M.; Schuur, Edward A.G.; Semenchuk, Philipp R.; Shaver, Gaius; Sonnentag, Oliver; Starr, Gregory; Treat, Claire C.; Waldrop, Mark P.; Wang, Yihui; Welker, Jeffrey; Wille, Christian; Xu, Xiaofeng; Zhang, Zhen; Zhuang, Qianlai; Zona, Donatella

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Year Published: 2019

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...

Moore, Thomas E.; Gautier, Donald L.; Gautier, Donald L.
Gautier, D.L., 2019, Geology and assessment of undiscovered oil and gas resources of the East Greenland Rift Basins Province, 2008, chap. K of Moore, T.E., and Gautier, D.L., eds., The 2008 Circum-Arctic Resource Appraisal: U.S. Geological Survey Professional Paper 1824, 20 p., https://doi.org/10.3133/pp1824K.

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Year Published: 2019

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...

Muessig, S.J.; Pennell, W.M.; Knott, Jeffrey R.; Calzia, James P.
Muessig, S.J., Pennell, W.M, Knott, J.R., and Calzia, J.P., 2019, Geology of the Monte Blanco borate deposits, Furnace Creek Wash, Death Valley, California: U.S. Geological Survey Open-File Report 2019–1111, 35, p., 2 plates, scales 1:2,400 and 1: 2,000, https://doi.org/10.3133/ofr20191111.

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Year Published: 2019

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...

Siler, Drew L.; Burns, Erick; James E Faulds

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Year Published: 2019

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...

James, E. Faulds; Hinz, Nicholas H.; Coolbaugh, Mark; Ayling, Bridget; Glen, Jonathan M.G.; Craig, Jason W.; McConnville, Emma; Siler, Drew L.; Queen, John; Witter, Jeff; Hardwick, Christian

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Year Published: 2019

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...

Petlyak, Helen; Cerovski-Darriau, Corina; Zaliva, Vadim; Stock, Jonathan D.

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Year Published: 2019

Geologic map of the Poncha Pass area, Chaffee, Fremont, and Saguache Counties, Colorado

This report presents a 1:24,000-scale geologic map, cross sections, and descriptive and interpretative text for the Poncha Pass area in central Colorado. The map area is irregular in shape, covering all of one 7 ½' quadrangle (Poncha Pass) and parts of five others (Mount Ouray, Maysville, Salida West, Salida East, and Wellsville). The map...

Minor, Scott A.; Caine, Jonathan Saul; Ruleman, Chester A.; Fridrich, Christopher J.; Chan, Christine F.; Brandt, Theodore R.; Holm-Denoma, Christopher S.; Morgan, Leah E.; Cosca, Michael A.; Grauch, V. J.
Minor, S.A., Caine, J.S., Ruleman, C.A., Fridrich, C.J., Chan, C.F., Brandt, T.R., Holm-Denoma, C.S., Morgan, L.E., Cosca, M.A., and Grauch, V.J.S., 2019, Geologic map of the Poncha Pass area, Chaffee, Fremont, and Saguache Counties, Colorado: U.S. Geological Survey Scientific Investigations Map 3436, 4 sheets, scale 1:24,000, https://doi.org/10.3133/sim3436.

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Year Published: 2019

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...

Guerin, Antoine; Jaboyefoff, Michel; Collins, Brian D.; Derron, Marc-Henri; Stock, Greg M.; Matasci, Battista; Boesiger, Martin; Lefeuvre, Caroline; Podladchikov, Yury Y.