Geologic setting, sedimentary architecture, and paragenesis of the Mesoproterozoic sediment-hosted Sheep Creek Cu-Co-Ag deposit, Helena embayment, Montana
Garth E. Graham, Murray W. Hitzman, Jerry Zieg
2012, Economic Geology (107) 1115-1141
The northern margin of the Helena Embayment contains extensive syngenetic to diagenetic massive pyrite horizons that extend over 25 km along the Volcano Valley-Buttress fault zone and extend up to 8 km basinward (south) within the Mesoproterozoic Newland Formation. The Sheep Creek Cu-Co deposit occurs within a structural block along...
Geologic processes influence the effects of mining on aquatic ecosystems
Travis S. Schmidt, William H. Clements, Richard B. Wanty, Philip L. Verplanck, Stan E. Church, Carma A. San Juan, David L. Fey, Barnaby W. Rockwell, Ed H. DeWitt, Terry L. Klein
2012, Ecological Applications (22) 870-879
Geologic processes strongly influence water and sediment quality in aquatic ecosystems but rarely are geologic principles incorporated into routine biomonitoring studies. We test if elevated concentrations of metals in water and sediment are restricted to streams downstream of mines or areas that may discharge mine wastes. We surveyed 198 catchments...
Industrial garnet
D.W. Olson
2012, Mining Engineering (64) 64-64
Garnet has been used as a gemstone since the Bronze Age. However, garnet's angular fractures, relatively high hardness and specific gravity, chemical inertness, and nontoxicity make it ideal for many industrial applications. It is also free of crystalline silica and can be recycled....
Avian botulism and avian chlamydiosis in wild water birds, Benton Lake National Wildlife Refuge, Montana, USA
Douglas E. Docherty, J. Christian Franson, Roger E. Brannian, Renee R. Long, Craig A. Radi, David Krueger, Robert F. Johnson
2012, Journal of Zoo and Wildlife Medicine (43) 885-888
In 1999, the U.S. Geological Survey (USGS) National Wildlife Health Center, Madison, Wisconsin, conducted a diagnostic investigation into a water bird mortality event involving intoxication with avian botulism type C and infection with avian chlamydiosis at the Benton Lake National Wildlife Refuge in Montana, USA. Of 24 carcasses necropsied, 11...
Evidence of autumn spawning in Suwannee River Gulf sturgeon, Acipenser oxyrinchus desotoi (Vladykov, 1955)
M.T. Randall, K. J. Sulak
2012, Journal of Applied Ichthyology (28) 489-495
Evidence of autumn spawning of Gulf sturgeon Acipenser oxyrinchus desotoi in the Suwannee River, Florida, was compiled from multiple investigations between 1986 and 2008. Gulf sturgeon are known from egg collections to spawn in the springtime months following immigration into rivers. Evidence of autumn spawning includes multiple captures of sturgeon...
Dwarf char, a new form of chars (the genus Salvelinus) in Lake Kronotskoe
S.D. Pavlov, E.A. Pivovarov, Carl O. Ostberg
2012, Doklady Biological Sciences (442) 20-23
Lake Kronotskoe is situated in the Kronotskii State Nature Reserve and is a unique natural heritage of Kamchatka. The lake–river system of the reserve includes numerous springs and small streams and three large inflowing rivers, Listvennichnaya, Unana, and Uzon, which form the main bays of...
Resolving hyporheic and groundwater components of streambed water flux
Aditi S. Bhaskar, Judson W. Harvey, Eric J. Henry
2012, Water Resources Research (48)
Hyporheic and groundwater fluxes typically occur together in permeable sediments beneath flowing stream water. However, streambed water fluxes quantified using the thermal method are usually interpreted as representing either groundwater or hyporheic fluxes. Our purpose was to improve understanding of co-occurring groundwater and hyporheic fluxes using streambed temperature measurements and...
Fingerprinting of glacial silt in lake sediments yields continuous records of alpine glaciation (35–15 ka), western USA
Joseph G. Rosenbaum, Richard L. Reynolds, Steven M. Colman
2012, Quaternary Research (78) 333-340
Fingerprinting glacial silt in last glacial-age sediments from Upper Klamath Lake (UKL) and Bear Lake (BL) provides continuous radiocarbon-dated records of glaciation for the southeastern Cascade Range and northwestern Uinta Mountains, respectively. Comparing of these records to cosmogenic exposure ages from moraines suggests that variations in glacial flour largely reflect...
A terrestrial lidar-based workflow for determining three-dimensional slip vectors and associated uncertainties
Peter O. Gold, Eric Cowgill, Oliver Kreylos, Ryan D. Gold
2012, Geosphere (8) 431-442
Three-dimensional (3D) slip vectors recorded by displaced landforms are difficult to constrain across complex fault zones, and the uncertainties associated with such measurements become increasingly challenging to assess as landforms degrade over time. We approach this problem from a remote sensing perspective by using terrestrial laser scanning (TLS) and 3D...
Demand surge following earthquakes
Anna H. Olsen
2012, Conference Paper, Proceedings of the 15th World Conference on Earthquake Engineering (15WCEE), Lisbon, Portugal, September 24-28
Demand surge is understood to be a socio-economic phenomenon where repair costs for the same damage are higher after large- versus small-scale natural disasters. It has reportedly increased monetary losses by 20 to 50%. In previous work, a model for the increased costs of reconstruction labor and materials was developed...
Fold-to-fault progression of a major thrust zone revealed in horses of the North Mountain fault zone, Virginia and West Virginia, USA
Randall C. Orndorff
2012, Journal of Geological Research (2012)
The method of emplacement and sequential deformation of major thrust zones may be deciphered by detailed geologic mapping of these important structures. Thrust fault zones may have added complexity when horse blocks are contained within them. However, these horses can be an important indicator of the fault development holding information...
Gypsum
R.D. Crangle Jr.
2012, Mining Engineering (64) 59-59
The United States is the world's fourth leading producer and consumer of gypsum. Production of gypsum in the U.S. during 2011 was estimated to be 9.4 Mt (103 million st), an increase of 6 percent compared with 2010 production. The average price of mined crude gypsum was $7/t ($6.35/st). Synthetic...
Hillslope hydrology and stability
Ning Lu, Jonathan Godt
2012, Book
Landslides are caused by a failure of the mechanical balance within hillslopes. This balance is governed by two coupled physical processes: hydrological or subsurface flow and stress. The stabilizing strength of hillslope materials depends on effective stress, which is diminished by rainfall. This book presents a cutting-edge quantitative approach to...
Holocene behavior of the Brigham City segment: implications for forecasting the next large-magnitude earthquake on the Wasatch fault zone, Utah
Stephen F. Personius, Christopher B. DuRoss, Anthony J. Crone
2012, Bulletin of the Seismological Society of America (102) 2265-2281
The Brigham City segment (BCS), the northernmost Holocene‐active segment of the Wasatch fault zone (WFZ), is considered a likely location for the next big earthquake in northern Utah. We refine the timing of the last four surface‐rupturing (~Mw 7) earthquakes at several sites near Brigham City (BE1, 2430±250; BE2, 3490±180;...
Arctic shorebirds in North America: A decade of monitoring
Jonathan R. Bart, Victoria H. Johnston, editor(s)
2012, Studies in Avian Biology 44
Each year shorebirds from North and South America migrate thousands of miles to spend the summer in the Arctic. There they feed in shoreline marshes and estuaries along some of the most productive and pristine coasts anywhere. With so much available food they are able to reproduce almost explosively; and...
Mineral resource of the month: tungsten
Kim B. Shedd
2012, Earth (57) 57-57
The article offers information on tungsten. It says that tungsten is a metal found in chemical compounds such as in the scheelite and ore minerals wolframite. It states that tungsten has the highest melting point and it forms a compound as hard as diamond when combined with carbon. It states...
Extraordinary distance limits of landslides triggered by the 2011 Mineral, Virginia, earthquake
Randall W. Jibson, Edwin L. Harp
2012, Bulletin of the Seismological Society of America (102) 2368-2377
The 23 August 2011 Mineral, Virginia, earthquake (Mw 5.8) was the largest to strike the eastern U.S. since 1897 and was felt over an extraordinarily large area. Although no large landslides occurred, the shaking did trigger many rock and soil falls from steep river banks and natural cliffs in the...
Geomagnetic detection of the sectorial solar magnetic field and the historical peculiarity of minimum 23-24
Jeffrey J. Love, J. Rigler
2012, Geophysical Research Letters (39)
[1] Analysis is made of the geomagnetic-activityaaindex covering solar cycle 11 to the beginning of 24, 1868–2011. Autocorrelation shows 27.0-d recurrent geomagnetic activity that is well-known to be prominent during solar-cycle minima; some minima also exhibit a smaller amount of 13.5-d recurrence. Previous work has shown that the recent solar...
2014 Update of the United States National Seismic Hazard Maps
M.D. Petersen, C.S. Mueller, K. M. Haller, M. Moschetti, S. C. Harmsen, E. H. Field, K.S. Rukstales, Y. Zeng, D. M. Perkins, P. Powers, S. Rezaeian, N. Luco, A. Olsen, R. Williams
2012, Conference Paper, Proceedings of the 15th World Conference on Earthquake Engineering (15WCEE), Lisbon, Portugal, September 24-28
The U.S. National Seismic Hazard Maps are revised every six years, corresponding with the update cycle of the International Building Code. These maps cover the conterminous U.S. and will be updated in 2014 using the best-available science that is obtained from colleagues at regional and topical workshops, which are convened...
New insights into gill ionocyte and ion transporter function in euryhaline and diadromous fish
Junya Hiroi, Stephen D. McCormick
2012, Respiratory Physiology and Neurobiology (184) 257-268
Teleost fishes are able to acclimatize to seawater by secreting excess NaCl by means of specialized “ionocytes” in the gill epithelium. Antibodies against Na+/K+-ATPase (NKA) have been used since 1996 as a marker for identifying branchial ionocytes. Immunohistochemistry of NKA by itself and in combination with Na+/K+/2Cl− cotransporter and CFTR...
Physical controls and predictability of stream hyporheic flow evaluated with a multiscale model
Susa H. Stonedahl, Judson W. Harvey, Joel Detty, Antoine Aubeneau, Aaron I. Packman
2012, Water Resources Research (48)
Improved predictions of hyporheic exchange based on easily measured physical variables are needed to improve assessment of solute transport and reaction processes in watersheds. Here we compare physically based model predictions for an Indiana stream with stream tracer results interpreted using the Transient Storage Model (TSM). We parameterized the physically...
Anisotropic path modeling to assess pedestrian-evacuation potential from Cascadia-related tsunamis in the US Pacific Northwest
Nathan J. Wood, Mathew C. Schmidtlein
2012, Natural Hazards (62) 275-300
Recent disasters highlight the threat that tsunamis pose to coastal communities. When developing tsunami-education efforts and vertical-evacuation strategies, emergency managers need to understand how much time it could take for a coastal population to reach higher ground before tsunami waves arrive. To improve efforts to model pedestrian evacuations from tsunamis,...
P-T-t conditions, Nd and Pb isotopic compositions and detrital zircon geochronology of the Massabesic Gneiss Complex, New Hampshire: isotopic and metamorphic evidence for the identification of Gander basement, central New England
Michael J. Dorais, Robert P. Wintsch, Michael J. Kunk, John Aleinikoff, William Burton, Christine Underdown, Charles M. Kerwin
2012, American Journal of Science (312) 1049-1097
We present new evidence for the assignment of the Neoproterozoic Massabesic Gneiss Complex of New Hampshire to the Gander terrane rather than the Avalon terrane. The majority of Avalonian (sensu stricto) igneous and meta-igneous rocks as defined in Maritime Canada have positive whole-rock ɛNd compared to more negative values for...
Bioenergetic response by steelhead to variation in diet, thermal habitat, and climate in the north Pacific Ocean
Margaret E. Atcheson, Katherine W. Myers, David A. Beauchamp, Nathan J. Mantua
2012, Transactions of the American Fisheries Society (141) 1081-1096
Energetic responses of steelhead Oncorhynchus mykiss to climate-driven changes in marine conditions are expected to affect the species’ ocean distribution, feeding, growth, and survival. With a unique 18-year data series (1991–2008) for steelhead sampled in the open ocean, we simulated interannual variation in prey consumption and growth efficiency of steelhead...
Effects of hurricanes Katrina and Rita on Louisiana black bear habitat
Joseph D. Clark, Jennifer L. Murrow
2012, Ursus (23) 192-205
The Louisiana black bear (Ursus americanus luteolus) is comprised of 3 subpopulations, each being small, geographically isolated, and vulnerable to extinction. Hurricanes Katrina and Rita struck the Louisiana and Mississippi coasts in 2005, potentially altering habitat occupied by this federally threatened subspecies. We used data collected on radio-telemetered bears from...
