Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2354
An overview of the petroleum geology of the Arctic
Nine main petroleum provinces containing recoverable resources totalling 61 Bbbl liquids+269 Bbbloe of gas are known in the Arctic. The three best known major provinces are: West Siberia–South Kara, Arctic Alaska and Timan–Pechora. They have been sourced principally from, respectively, Upper Jurassic, Triassic and Devonian marine source rocks and their hydrocarbons are reservoired principally in C
Authors
A.M. Spencer, A.F. Embry, Donald L. Gautier, A.V. Stoupakova, K. Sorensen
Age, composition, and areal distribution of the Pliocene Lawlor Tuff, and three younger Pliocene tuffs, California and Nevada
The Lawlor Tuff is a widespread dacitic tephra layer produced by Plinian eruptions and ash flows derived from the Sonoma Volcanics, a volcanic area north of San Francisco Bay in the central Coast Ranges of California, USA. The younger, chemically similar Huichica tuff, the tuff of Napa, and the tuff of Monticello Road sequentially overlie the Lawlor Tuff, and were erupted from the same volcanic fi
Authors
Andrei M. Sarna-Wojcicki, Alan L. Deino, Robert J. Fleck, Robert J. McLaughlin, David Wagner, Elmira Wan, David B. Wahl, John W. Hillhouse, Michael Perkins
An analysis of modern pollen rain from the Maya lowlands of northern Belize
In the lowland Maya area, pollen records provide important insights into the impact of past human populations and climate change on tropical ecosystems. Despite a long history of regional paleoecological research, few studies have characterized the palynological signatures of lowland ecosystems, a fact which lowers confidence in ecological inferences made from palynological data. We sought to veri
Authors
T. Bhattacharya, T. Beach, David B. Wahl
Ammonium in thermal waters of Yellowstone National Park: Processes affecting speciation and isotope fractionation
Dissolved inorganic nitrogen, largely in reduced form (NH4(T)≈NH4(aq)++NH3(aq)o), has been documented in thermal waters throughout Yellowstone National Park, with concentrations ranging from a few micromolar along the Firehole River to millimolar concentrations at Washburn Hot Springs. Indirect evidence from rock nitrogen analyses and previous work on organic compounds associated with Washburn Hot
Authors
J.M. Holloway, D. Kirk Nordstrom, J.K. Böhlke, R. Blaine McCleskey, J. W. Ball
Three-dimensional model of an ultramafic feeder system to the Nikolai Greenstone mafic large igneous province, central Alaska Range
The Amphitheater Mountains and southern central Alaska Range expose a thick sequence of Triassic Nikolai basalts that is underlain by several mafic‐ultramafic complexes, the largest and best exposed being the Fish Lake and Tangle (FL‐T) mafic‐ultramafic sills that flank the Amphitheater Mountains synform. Three‐dimensional (3‐D) modeling of gravity and magnetic data reveals details of the structur
Authors
Jonathan M.G. Glen, Jeanine M. Schmidt, G. G. Connard
Deciphering fluid sources of hydrothermal systems: A combined Sr- and S-isotope study on barite (Schwarzwald, SW Germany)
Primary and secondary barites from hydrothermal mineralizations in SW Germany were investigated, for the first time, by a combination of strontium (Sr) isotope systematics (87Sr/86Sr), Sr contents and δ34S values to distinguish fluid sources and precipitation mechanisms responsible for their formation. Barite of Permian age derived its Sr solely from crystalline basement rocks, whereas all younger
Authors
S. Staude, S. Gob, K. Pfaff, F. Strobele, W. R. Premo, G. Markl
Disaster risk assessment case study: Recent drought on the Navajo Nation, USA
The Navajo Nation is an ecologically sensitive semi-arid to arid section of the southern Colorado Plateau. In this remote part of the United States, located at the Four Corners (Arizona, New Mexico, Colorado, and Utah), traditional people live a subsistence lifestyle that is inextricably tied to, and dependent upon, landscape conditions and water supplies. Soft bedrock lithologies and sand dunes d
Authors
Margaret Hiza, Klara B. Kelley, Harris Francis, Debra Block
Introduction: Tectonics, volcanism, and stratigraphy within the evolving transform margin north of San Francisco Bay, California
No abstract available.
Authors
Victoria E. Langenheim, Donald S. Sweetkind
Episodic growth of a Late Cretaceous and Paleogene intrusive complex of pegmatitic leucogranite, Ruby Mountains core complex, Nevada, USA
Gneissic pegmatitic leucogranite forms a dominant component (>600 km3) of the midcrustal infrastructure of the Ruby Mountains–East Humboldt Range core complex (Nevada, USA), and was assembled and modified episodically into a batholithic volume by myriad small intrusions from ca. 92 to 29 Ma. This injection complex consists of deformed sheets and other bodies emplaced syntectonically into a stratig
Authors
Keith A. Howard, J. L. Wooden, C. G. Barnes, W. R. Premo, A.W. Snoke, S.-Y. Lee
Stratigraphy and chronology of offshore to nearshore deposits associated with the Provo shoreline, Pleistocene Lake Bonneville, Utah
Stratigraphic descriptions and radiocarbon data from eleven field locations are presented in this paper to establish a chronostratigraphic framework for offshore to nearshore deposits of Lake Bonneville. Based on key marker beds and geomorphic position, the deposits are interpreted to have accumulated during the period from the late transgressive phase, through the overflowing phase, into the regr
Authors
Holly S. Godsey, Charles G. Oviatt, David M. Miller, Marjorie A. Chan
Geologic map of Detrital, Hualapai, and Sacramento Valleys and surrounding areas, northwest Arizona
A 1:250,000-scale geologic map and report covering the Detrital, Hualapai, and Sacramento valleys in northwest Arizona is presented for the purpose of improving understanding of the geology and geohydrology of the basins beneath those valleys. The map was compiled from existing geologic mapping, augmented by digital photogeologic reconnaissance mapping. The most recent geologic map for the area, a
Authors
L. Sue Beard, Jeffrey Kennedy, Margot Truini, Tracey Felger
Stratigraphy and depositional environments of the upper Pleistocene Chemehuevi Formation along the lower Colorado River
The Chemehuevi Formation forms a conspicuous, widespread, and correlative set of nonmarine sediments lining the valleys of the Colorado River and several of its larger tributaries in the Basin and Range geologic province. These sediments have been examined by geologists since J. S. Newberry visited the region in 1857 and are widely cited in the geologic literature; however their origin remains unr
Authors
Daniel V. Malmon, Keith A. Howard, P. Kyle House, Scott C. Lundstrom, Philip A. Pearthree, Andrei M. Sarna-Wojcicki, Elmira Wan, David B. Wahl