Mineral parageneses, regional architecture, and tectonic evolution of Franciscan metagraywackes, Cape Mendocino-Garberville-Covelo 30' x 60' quadrangles, northwest California
W. G. Ernst, Robert J. McLaughlin
2012, Tectonics (31)
The Franciscan Complex is a classic subduction-zone assemblage. In northwest California, it comprises a stack of west vergent thrust sheets: westernmost Eastern Belt outliers; Central Belt mélange; Coastal Belt Yager terrane; Coastal Belt Coastal terrane; Coastal Belt King Range/False Cape terranes. We collected samples and determined P-T conditions of recrystallization...
The Middle Ordovician Knox unconformity in the Black Warrior Basin
Gary S. Dwyer, John E. Repetski
2012, Book chapter, The great American carbonate bank: The geology and economic resources of the Cambrian-Ordovician Sauk megasequence of Laurentia
Analysis of well core and cuttings from the Black Warrior Basin in Mississippi reveals the presence of a Middle Ordovician (Whiterockian) erosional unconformity interpreted to be equivalent to the well-known Knox-Beekmantown unconformity in eastern North America. The unconformity occurs at the top of a peritidal dolostone unit known informally as...
Ordovician of the Sauk megasequence in the Ozark region of northern Arkansas and parts of Missouri and adjacent states
Raymond L. Ethington, John E. Repetski, James R. Derby
2012, AAPG Memoir (98) 275-300
Exposures of Ordovician rocks of the Sauk megasequence in Missouri and northern Arkansas comprise Ibexian and lower Whiterockian carbonates with interspersed sandstones. Subjacent Cambrian strata are exposed in Missouri but confined to the subsurface in Arkansas. The Sauk-Tippecanoe boundary in this region is at the base of the St. Peter...
Population fragmentation and inter-ecosystem movements of grizzly bears in Western Canada and the Northern United States
M.F. Proctor, David Paetkau, B. N. McLellan, G.B. Stenhouse, K.C. Kendall, R.D. Mace, W.F. Kasworm, C. Servheen, C.L. Lausen, M.L. Gibeau, W.L. Wakkinen, M.A. Haroldson, G. Mowat, C.D. Apps, L.M. Ciarniello, R.M.R. Barclay, M.S. Boyce, C.C. Schwartz, C. Strobeck
2012, Wildlife Monographs 1-46
Population fragmentation compromises population viability, reduces a species ability to respond to climate change, and ultimately may reduce biodiversity. We studied the current state and potential causes of fragmentation in grizzly bears over approximately 1,000,000 km 2 of western Canada, the northern United States (US), and southeast Alaska. We...
Keanakākoʻi Tephra produced by 300 years of explosive eruptions following collapse of Kīlauea's caldera in about 1500 CE
Donald A. Swanson, Timothy R. Rose, Richard S. Fiske, John P. McGeehin
2012, Journal of Volcanology and Geothermal Research (215-216) 8-25
The Keanakākoʻi Tephra at Kīlauea Volcano has previously been interpreted by some as the product of a caldera-forming eruption in 1790 CE. Our study, however, finds stratigraphic and 14C evidence that the tephra instead results from numerous eruptions throughout a 300-year period between about 1500 and 1800. The stratigraphic evidence includes:...
Empirical methods for detecting regional trends and other spatial expressions in antrim shale gas productivity, with implications for improving resource projections using local nonparametric estimation techniques
Timothy C. Coburn, Philip A. Freeman, Emil D. Attanasi
2012, Natural Resources Research (21) 1-21
The primary objectives of this research were to (1) investigate empirical methods for establishing regional trends in unconventional gas resources as exhibited by historical production data and (2) determine whether or not incorporating additional knowledge of a regional trend in a suite of previously established local nonparametric resource prediction algorithms...
Magnetostratigraphy susceptibility for the Guadalupian Series GSSPs (Middle Permian) in Guadalupe Mountains National Park and adjacent areas in West Texas
Bruce R. Wardlaw, Brooks B. Ellwood, Lance L. Lambert, Jonathan H. Tomkin, Gordon L. Bell, Galina P. Nestell
2012, Geological Society, London, Special Publications (373) 21-21
Here we establish a magnetostratigraphy susceptibility zonation for the three Middle Permian Global boundary Stratotype Sections and Points (GSSPs) that have recently been defined, located in Guadalupe Mountains National Park, West Texas, USA. These GSSPs, all within the Middle Permian Guadalupian Series, define (1) the base of the Roadian Stage...
Origins of mineral deposits, Belt-Purcell Basin, United States and Canada: An introduction
Stephen E. Box, Arthur A. Bookstrom, Robert G. Anderson
2012, Economic Geology (107) 1081-1088
The fill of the Mesoproterozoic Belt-Purcell Basin, which straddles the United States-Canada border within the Rocky Mountains of western North America (Fig. 1), consists of marine and nonmarine clastic and carbonate strata 15 to 20 km thick. Three giant metal-producing ore deposits or districts account...
Contrasting extreme long-distance migration patterns in bar-tailed godwits Limosa lapponica
Phil F. Battley, Nils Warnock, T. Lee Tibbitts, Robert E. Gill Jr., Theunis Piersma, Chris J. Hassell, David C. Douglas, Daniel M. Mulcahy, Brett D. Gartrell, Rob Schuckard, David S. Melville, Adrian C. Riegen
2012, Journal of Avian Biology (43) 21-32
Migrating birds make the longest non-stop endurance flights in the animal kingdom. Satellite technology is now providing direct evidence on the lengths and durations of these flights and associated staging episodes for individual birds. Using this technology, we compared the migration performance of two subspecies of bar-tailed godwit Limosa lapponica travelling between...
A new perspective on the geometry of the San Andreas Fault in southern California and its relationship to lithospheric structure
Gary S. Fuis, Daniel S. Scheirer, Victoria E. Langenheim, Monica D. Kohler
2012, Bulletin of the Seismological Society of America (102) 236-251
The widely held perception that the San Andreas fault (SAF) is vertical or steeply dipping in most places in southern California may not be correct. From studies of potential‐field data, active‐source imaging, and seismicity, the dip of the SAF is significantly nonvertical in many locations. The direction of dip appears...
Definition of Greater Gulf Basin Lower Cretaceous and Upper Cretaceous lower Cenomanian Shale Gas Assessment Unit, United States Gulf of Mexico basin onshore and state waters
Kristin O. Dennen, Paul C. Hackley
2012, Search and Discovery
An assessment unit (AU) for undiscovered continuous “shale” gas in Lower Cretaceous (Aptian and Albian) and basal Upper Cretaceous (lower Cenomanian) rocks in the USA onshore Gulf of Mexico coastal plain recently was defined by the U.S. Geological Survey (USGS). The AU is part of the Upper Jurassic-Cretaceous-Tertiary Composite Total...
Use of occupancy models to evaluate expert knowledge-based species-habitat relationships
Monica N. Iglecia, Jaime A. Collazo, Alexa McKerrow
2012, Avian Conservation and Ecology (7) 1-13
Expert knowledge-based species-habitat relationships are used extensively to guide conservation planning, particularly when data are scarce. Purported relationships describe the initial state of knowledge, but are rarely tested. We assessed support in the data for suitability rankings of vegetation types based on expert knowledge for three terrestrial avian species in...
Influence of fault trend, bends, and convergence on shallow structure and geomorphology of the Hosgri strike-slip fault, offshore central California
Samuel Y. Johnson, Janet Tilden Watt
2012, Geosphere (8) 1632-1656
We mapped an ∼94-km-long portion of the right-lateral Hosgri fault zone in offshore central California using a dense network of high-resolution seismic reflection profiles, marine magnetic data, and multibeam bathymetry. These data document the location, length, and continuity of multiple fault strands, highlight fault-zone heterogeneity, and demonstrate the importance...
The Quaternary thrust system of the northern Alaska Range
Sean P. Bemis, Gary A. Carver, Richard D. Koehler
2012, Geosphere (8) 196-205
The framework of Quaternary faults in Alaska remains poorly constrained. Recent studies in the Alaska Range north of the Denali fault add significantly to the recognition of Quaternary deformation in this active orogen. Faults and folds active during the Quaternary occur over a length of ∼500 km along the...
Illumination of rheological mantle heterogeneity by the M7.2 2010 El Mayor-Cucapah earthquake
Fred F. Pollitz, Roland Bürgmann, Wayne R. Thatcher
2012, Geochemistry, Geophysics, Geosystems (13)
Major intracontinental strike-slip faults tend to mark boundaries between lithospheric blocks of contrasting mechanical properties along much of their length. Both crustal and mantle heterogeneities can form such boundaries, but the role of crustal versus mantle strength contrasts for localizing strain sufficiently to generate major faults remains unclear. Using the...
The Neoacadian orogenic core of the souther Appalachians: A geo-traverse through the migmatitic inner Piedmont from the Brushy Mountains to Lincolnton, North Carolina
Arthur J. Merschat, Robert D. Hatcher Jr., Heather E. Byars, G. Williams
Martha Cary Eppes, Mervin J. Bartholomew, editor(s)
2012, Book chapter, From the Blue Ridge to the coastal plain: Field excursions in the southeastern United States
The Inner Piedmont extends from North Carolina to Alabama and comprises the Neoacadian (360–345 Ma) orogenic core of the southern Appalachian orogen. Bordered to west by the Blue Ridge and the exotic Carolina superterrane to the east, the Inner Piedmont is cored by an extensive region of migmatitic, sillimanite-grade rocks....
Spatial analysis of geologic and hydrologic features relating to sinkhole occurrence in Jefferson County, West Virginia
Daniel H. Doctor, Katarina Z. Doctor
2012, Carbonates and Evaporites (27) 143-152
In this study the influence of geologic features related to sinkhole susceptibility was analyzed and the results were mapped for the region of Jefferson County, West Virginia. A model of sinkhole density was constructed using Geographically Weighted Regression (GWR) that estimated the relations among discrete geologic or hydrologic features and...
Hermit Thrush (Catharus guttatus)
Petra Wood, Therese M. Donovan
2012, The Birds of North America
With spotted breast and reddish tail, the Hermit Thrush lives up to its name. Although celebrated for its ethereal song, it is mostly a quiet and unobtrusive bird that spends much of its time in the lower branches of the undergrowth or on the forest floor, often seen flicking its...
The paleohydrology of unsaturated and saturated zones at Yucca Mountain, Nevada, and vicinity
James B. Paces, Joseph F. Whelan
John S. Stuckless, editor(s)
2012, Book chapter, Hydrology and geochemistry of Yucca Mountain and vicinity, Southern Nevada and California
Surface, unsaturated-zone, and saturated-zone hydrologic conditions at Yucca Mountain responded to past climate variations and are at least partly preserved by sediment, fossil, and mineral records. Characterizing past hydrologic conditions in surface and subsurface environments helps to constrain hydrologic responses expected under future climate conditions and improve predictions of repository...
Digital outcrop model of stratigraphy and breccias of the southern Franklin Mountains, El Paso, Texas
Jerome A. Bellian, Charles Kerans, John E. Repetski
James R. Derby, R.D. Fritz, S.A. Longacre, W.A. Morgan, C.A. Sternbach, editor(s)
2012, Book chapter, The great American carbonate bank: The geology and economic resources of the Cambrian-Ordovician Sauk megasequence of Laurentia
This chapter reviews and synthesizes the lithostratigraphy, biostratigraphy, chronostratigraphy, and breccia types of the southwestern part of the great American carbonate bank in the southern Franklin Mountains (SFM), El Paso, Texas. Primary stratigraphic units of focus are the Lower Ordovician El Paso and Upper Ordovician Montoya Groups. These groups preserve...
Influences of the El Niño Southern Oscillation and the Pacific Decadal Oscillation on the timing of the North American spring
Gregory J. McCabe, Toby R. Ault, Benjamin I. Cook, Julio L. Betancourt, Mark D. Schwartz
2012, International Journal of Climatology (32) 2301-2310
Detrended, modelled first leaf dates for 856 sites across North America for the period 1900–2008 are used to examine how the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) separately and together might influence the timing of spring. Although spring (mean March through April) ENSO and PDO...
Nearshore disposal of fine-grained sediment in a high-energy environment: Santa Cruz Harbor case study
Katherine Cronin, Maarten van Ormondt, Curt D. Storlazzi, Katherine Presto, Pieter K. Tonnon
Julie D. Rosati, Ping Wang, Tiffany M. Roberts, editor(s)
2011, Book, The Proceedings of the Coastal Sediments 2011
Current regulations in California prohibit the disposal of more than 20% fine-grained sediment in the coastal zone; this threshold is currently being investigated to determine if this environmental regulation can be improved upon. A field monitoring and numerical modeling experiment took place late 2 009 to determine the fate...
Concentrations, loads, and sources of polychlorinated biphenyls, Neponset River and Neponset River Estuary, eastern Massachusetts
Robert F. Breault
2011, Scientific Investigations Report 2011-5004
Polychlorinated biphenyls (PCBs) are known to contaminate the Neponset River, which flows through parts of Boston, Massachusetts, and empties into the Neponset River Estuary, an important fish-spawning area. The river is dammed and impassable to fish. The U.S. Geological Survey, in cooperation with the Massachusetts Department of Fish and Game,...
Tampa Bay
Lawrence R. Handley, Kathryn Spear, Lindsay Cross, René Baumstark, Ryan Moyer, Cindy A. Thatcher
2011, Report, Emergent wetlands status and trends in the northern Gulf of Mexico: 1950-2010
Tampa Bay is Florida’s largest open-water estuary and encompasses an area of approximately 1036 km2 (400 mi2) (Burgan and Engle, 2006; TBNEP, 2006). The Bay’s watershed drains 5,698 km2 (2,200 mi2) of land and includes freshwater from the Hillsborough River to the north east, the Alafia and Little Manatee rivers...
Characterizing climate-change impacts on the 1.5-yr flood flow in selected basins across the United States: a probabilistic approach
John F. Walker, Lauren E. Hay, Steven L. Markstrom, Michael D. Dettinger
2011, Earth Interactions (15) 1-16
The U.S. Geological Survey Precipitation-Runoff Modeling System (PRMS) model was applied to basins in 14 different hydroclimatic regions to determine the sensitivity and variability of the freshwater resources of the United States in the face of current climate-change projections. Rather than attempting to choose a most likely scenario from the...
