Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2486
Unravelling the tectonics of Pearya Terrane, Nunavut: GEM-2 Western Arctic Project, report of activities 2018 Unravelling the tectonics of Pearya Terrane, Nunavut: GEM-2 Western Arctic Project, report of activities 2018
GSC scientists were part of an international team of researchers who visited bedrock outcrops on northernmost Ellesmere Island in the summer of 2017. The purpose of the expedition was to document and sample the rocks of Pearya terrane and study the tectonic history of the terrane in order to better reconstruct the past stages of continental drift that formed the Arctic Ocean.
Authors
Thomas Hadlari, Nicole M. Rayner, Thomas E. Moore
The Bouse Formation: A controversial Neogene archive of the evolving Colorado River: A scientific drilling workshop report (Feb. 28-March 3, 2019-Bluewater Resort, Parker, Arizona, USA The Bouse Formation: A controversial Neogene archive of the evolving Colorado River: A scientific drilling workshop report (Feb. 28-March 3, 2019-Bluewater Resort, Parker, Arizona, USA
Neogene deposits of the lower Colorado River valley, especially the Miocene(?) and early Pliocene Bouse Formation, have been the focus of intense debate regarding the early paleoenvironmental history of this important continental-scale river system in southwestern North America and its integration with the proto-Gulf of California. Fine-grained units within these Neogene deposits also...
Authors
Andrew S. Cohen, Colleen Cassidy, Ryan S. Crow, Jordon Bright, Laura Crossey, Rebecca Dorsey, Brian F. Gootee, Kyle House, Keith A. Howard, Karl Karlstrom, Philip Pearthree
Low O2 level enhances CH4-derived carbon flow into microbial communities in landfill cover soils Low O2 level enhances CH4-derived carbon flow into microbial communities in landfill cover soils
CH4 oxidation in landfill cover soils plays a significant role in mitigating CH4 release to the atmosphere. Oxygen availability and the presence of co-contaminants are potentially important factors affecting CH4 oxidation rate and the fate of CH4-derived carbon. In this study, microbial populations that oxidize CH4 and the subsequent conversion of CH4-derived carbon into CO2, soil...
Authors
Ruo He, Yao Su, Mary-Cathrine Leewis, Yi-Xuan Chu, Jing Wang, Ruo-Chan Ma, Donglei Wu, Liang-Tong Zhan, Ian Charold Herriott, Mary Beth Leigh
Using stream-side groundwater discharge for geochemical exploration in mountainous terrain Using stream-side groundwater discharge for geochemical exploration in mountainous terrain
Groundwater chemistry has been predominantly used in geochemical exploration studies to identify mineralized targets concealed under transported cover in areas with gentle topography. Another potentially valuable ap-plication that has received little attention is using groundwater chemistry to identify deposits concealed within mountain ridges. A number of geochemical exploration studies...
Authors
Andrew H. Manning, Jean M. Morrison, Richard Wanty, Christopher T. Mills
Geologic field photograph map of the Grand Canyon region, 1967–2010 Geologic field photograph map of the Grand Canyon region, 1967–2010
The Grand Canyon geologic field photograph collection contains 1,211 geotagged photographs collected during 43 years of geologic mapping from 1967 to 2010. The photographs document some key geologic features, structures, and rock unit relations that were used to compile nine geologic maps of the Grand Canyon region published at 1:100,000 scale, and many more maps published at 1:24,000...
Authors
George H. Billingsley, Gregory Goodwin, Sarah E. Nagorsen, Monica E. Erdman, Jason T. Sherba
A new set of basaltic tephras from southeastern Alaska represent key stratigraphic markers for the late Pleistocene A new set of basaltic tephras from southeastern Alaska represent key stratigraphic markers for the late Pleistocene
An 8-cm-thick black basaltic tephra with nine discrete normally graded beds is present in cores from a lake on Baker Island in southeastern Alaska. The estimated age of the tephra is 13,492 ± 237 cal yr BP. Although similar in age to the MEd tephra from the adjacent Mt. Edgecumbe Volcanic Field, this tephra is geochemically distinct. Black basaltic tephras recovered from two additional...
Authors
Paul S. Wilcox, Jason A. Addison, Sarah J. Fowell, James F. Baichtal, Ken Severin, Daniel H. Mann
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