Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2354
Accumulation of impact markers in desert wetlands and implications for the Younger Dryas impact hypothesis
The Younger Dryas impact hypothesis contends that an extraterrestrial object exploded over North America at 12.9 ka, initiating the Younger Dryas cold event, the extinction of many North American megafauna, and the demise of the Clovis archeological culture. Although the exact nature and location of the proposed impact or explosion remain unclear, alleged evidence for the fallout comes from multip
Authors
Jeffrey S. Pigati, Claudio Latorre, Jason A. Rech, Julio L. Betancourt, Katherine E. Martinez, James R. Budahn
Uplift history of the Sila Massif, southern Italy, deciphered from cosmogenic 10Be erosion rates and river longitudinal profile analysis
The Sila Massif in the Calabrian Arc (southern Italy) is a key site to study the response of a landscape to rock uplift. Here an uplift rate of ∼1 mm/yr has imparted a deep imprint on the Sila landscape recorded by a high-standing low-relief surface on top of the massif, deeply incised fluvial valleys along its flanks, and flights of marine terraces in the coastal belt. In this framework, we combi
Authors
Valerio Olivetti, Andrew J. Cyr, Paola Molin, Claudio Faccenna, Darryl E. Granger
Geophysical study of the San Juan Mountains batholith complex, southwestern Colorado
One of the largest and most pronounced gravity lows over North America is over the rugged San Juan Mountains of southwestern Colorado (USA). The mountain range is coincident with the San Juan volcanic field (SJVF), the largest erosional remnant of a widespread mid-Cenozoic volcanic field that spanned much of the southern Rocky Mountains. A buried, low-density silicic batholith complex related to t
Authors
Benjamin J. Drenth, G. Randy Keller, Ren A. Thompson
Geochemical data from groundwater at the proposed Dewey Burdock uranium in-situ recovery mine, Edgemont, South Dakota
This report releases groundwater geochemistry data from samples that were collected in June 2011 at the Dewey Burdock proposed uranium in-situ recovery site near Edgemont, South Dakota. The sampling and analytical methods are summarized, and all of the data, including quality assurance/quality control information are provided in data tables.
Authors
Raymond H. Johnson
Migrated hydrocarbons in exposure of Maastrichtian nonmarine strata near Saddle Mountain, lower Cook Inlet, Alaska
Magoon and others (1980) described an 83-meter- (272-foot-) thick succession of Maastrichtian (Upper Cretaceous)
conglomerate, sandstone, mudstone, and coal exposed on the south side of an unnamed drainage, approximately 3 kilometers
(1.8 miles) east of Saddle Mountain in lower Cook Inlet (figs. 1 and 2). The initial significance of this exposure was that
it was the first reported occurrence of no
Authors
D. L. LePain, P. G. Lillis, K. P. Helmold, R. G. Stanley
Projected climate and vegetation changes and potential biotic effects for Fort Benning, Georgia; Fort Hood, Texas; and Fort Irwin, California
The responses of species and ecosystems to future climate changes will present challenges for conservation and natural resource managers attempting to maintain both species populations and essential habitat. This report describes projected future changes in climate and vegetation for three study areas surrounding the military installations of Fort Benning, Georgia, Fort Hood, Texas, and Fort Irwin
Authors
S.L. Shafer, J. Atkins, B.A. Bancroft, P. J. Bartlein, J.J. Lawler, B. Smith, C.B. Wilsey
Assessing time-integrated dissolved concentrations and predicting toxicity of metals during diel cycling in streams
Evaluating water quality and the health of aquatic organisms is challenging in systems with systematic diel (24 hour) or less predictable runoff-induced changes in water composition. To advance our understanding of how to evaluate environmental health in these dynamic systems, field studies of diel cycling were conducted in two streams (Silver Bow Creek and High Ore Creek) affected by historical
Authors
Laurie S. Balistrieri, David A. Nimick, Christopher A. Mebane
Quaternary geologic map of the Havre 1° x 2° quadrangle
The Havre quadrangle encompasses approximately 16,084 km2 (6,210 mi2). The northern boundary is the Montana/Saskatchewan (U.S./Canada) boundary. The quadrangle is in the Northern Plains physiographic province and it includes parts of the Bearpaw Mountains, the Little Rocky Mountains, and the Boundary Plateau. The primary river is the Milk River. The ancestral Missouri River was diverted south of t
Authors
David S. Compilations by Fullerton, Roger B. Colton, Charles A. Bush
Progressive failure of sheeted rock slopes: the 2009–2010 Rhombus Wall rock falls in Yosemite Valley, California, USA
Progressive rock-fall failures in natural rock slopes are common in many environments, but often elude detailed quantitative documentation and analysis. Here we present high-resolution photography, video, and laser scanning data that document spatial and temporal patterns of a 15-month-long sequence of at least 14 rock falls from the Rhombus Wall, a sheeted granitic cliff in Yosemite Valley, Calif
Authors
Greg M. Stock, Stephen J. Martel, Brian D. Collins, Edwin L. Harp
Sea-level history during the Last Interglacial complex on San Nicolas Island, California: implications for glacial isostatic adjustment processes, paleozoogeography and tectonics
San Nicolas Island, California has one of the best records of fossiliferous Quaternary marine terraces in North America, with at least fourteen terraces rising to an elevation of ~270 m above present-day sea level. In our studies of the lowest terraces, we identified platforms at 38-36 m (terrace 2a), 33-28 m (terrace 2b), and 13-8 m (terrace 1). Uranium-series dating of solitary corals from these
Authors
Daniel R. Muhs, Kathleen R. Simmons, R. Randall Schumann, Lindsey T. Groves, Jerry X. Mitrovica, Deanna Laurel
Zinc isotope investigation of surface and pore waters in a mountain watershed impacted by acid rock drainage
The pollution of natural waters with metals derived from the oxidation of sulfide minerals like pyrite is a global environmental problem. However, the metal loading pathways and transport mechanisms associated with acid rock drainage reactions are often difficult to characterize using bulk chemical data alone. In this study, we evaluated the use of zinc (Zn) isotopes to complement traditional geoc
Authors
Suzan Aranda, David M. Borrok, Richard B. Wanty, Laurie S. Balistrieri
Preliminary geologic map of the Big Costilla Peak area, Taos County, New Mexico, and Costilla County, Colorado
This map covers the Big Costilla Peak, New Mex.‒Colo. quadrangle and adjacent parts of three other 7.5 minute quadrangles: Amalia, New Mex.‒Colo., Latir Peak, New Mex., and Comanche Point, New Mex. The study area is in the southwesternmost part of that segment of the Sangre de Cristo Mountains known as the Culebra Range; the Taos Range segment lies to the southwest of Costilla Creek and its tribut
Authors
Christopher J. Fridrich, Ralph R. Shroba, Adam M. Hudson