Chapter 21 Western phosphate field - Depositional and economic deposit models
Phillip R. Moyle, David Z. Piper
2004, Handbook of Exploration and Environmental Geochemistry (8) 575-598
The Western Phosphate Field (WPF), composed of Permian marine sedimentary strata that cover over 300,000 km2 in the middle Rocky Mountains of Idaho, Montana, Utah, and Wyoming in the United States, contains vast resources of phosphate mined for fertilizer and a range of other industrial applications. The richest deposits of...
Posteruption suspended sediment transport at Mount St. Helens: Decadal‐scale relationships with landscape adjustments and river discharges
Jon J. Major
2004, Journal of Geophysical Research (109)
Widespread landscape disturbance by the cataclysmic 1980 eruption of Mount St. Helens abruptly increased sediment supply in surrounding watersheds. The magnitude and duration of the redistribution of sediment deposited by the eruption as well as decades‐ to centuries‐old sediment remobilized from storage have varied chiefly with the...
Mineral stimulation of subsurface microorganisms: release of limiting nutrients from silicates
Jennifer Roberts Roger, Philip C. Bennett
2004, Chemical Geology (203) 91-108
Microorganisms play an important role in the weathering of silicate minerals in many subsurface environments, but an unanswered question is whether the mineral plays an important role in the microbial ecology. Silicate minerals often contain nutrients necessary for microbial growth, but whether the microbial community benefits from their release...
Digital elevation extraction from multiple MTI data sets
Jeffrey A. Mercier, Robert A. Schowengerdt, James C. Storey, Jody L. Smith
2004, Conference Paper
The Digital Elevation Model (DEM) extraction process traditionally uses a stereo pair of aerial photographs that are sequentially captured using an airborne metric camera. Standard DEM extraction techniques have been naturally extended to utilize satellite imagery. However, the particular characteristics of satellite imaging can cause difficulties in the DEM extraction...
Formation of modern and Paleozoic stratiform barite at cold methane seeps on continental margins: Comment and Reply: Comment
Poul Emsbo, Craig A. Johnson
2004, Geology (32) e64-e65
No abstract available....
Two stages of deformation and fluid migration in the west-central Brooks Range fold-and-thrust belt, Northern Alaska
Thomas E. Moore, Christopher J. Potter, Paul B. O'Sullivan, Kevin L. Shelton, Michael B. Underwood
2004, Book chapter
The Brooks Range is a north-directed fold and thrust belt that forms the southern boundary of the North Slope petroleum province in northern Alaska. Field-based studies have long recognized that large-magnitude, thin-skinned folding and thrusting in the Brooks Range occurred during arc-continent collision in the Middle Jurassic to Early Cretaceous...
Paleozoic sedimentary rocks in the Red Dog Zn-Pb-Ag district and vicinity, western Brooks Range, Alaska: provenance, deposition, and metallogenic significance
John F. Slack, Julie A. Dumoulin, J.M. Schmidt, L. E. Young, Cameron Rombach
2004, Economic Geology (99) 1385-1414
Geochemical analyses of Paleozoic sedimentary rocks in the western Brooks Range reveal a complex evolutionary history for strata surrounding the large Zn-Pb-Ag deposits of the Red Dog district. Data for major elements, trace elements, and rare earth elements (REE) were obtained on 220 samples of unaltered and unmineralized siliciclastic rocks...
A kinematic model for the southern Alaska orocline based on regional fault patterns
Jonathan M.G. Glen
Aviva J. Sussman, Arlo B. Weil, editor(s)
2004, Book chapter, Orogenic curvature: Integrating paleomagnetic and structural analyses
Among the most prominent physiographic features of southern Alaska are a series of nested arcuate lineations, including the Denali fault, that parallel the concave-southward southern coastline of the state. These features are generally interpreted as major dextral shear zones that formed in the Late Cretaceous to early Tertiary in response...
Nature of hydrothermal fluids at the shale-hosted Red Dog Zn-Pb-Ag deposits, Brooks Range, Alaska
David L. Leach, Erin E. Marsh, Poul Emsbo, Cameron Rombach, Karen D. Kelley, Michael W. Anthony
2004, Economic Geology (99) 1449-1480
The Red Dog Zn-Pb-Ag district in the western Brooks Range, northern Alaska, contains numerous shale-hosted Zn-Pb sulfide and barite deposits in organic-rich siliceous mudstone and shale, chert, and carbonate rocks of the Carboniferous Kuna Formation. The giant Red Dog shale-hosted deposits consist of a cluster of four orebodies (Main, Qanaiyaq,...
The Colorado front range: anatomy of a Laramide uplift
Karl S. Kellogg, Bruce Bryant, John C. Reed
2004, Book chapter, GSA Field Guide
Along a transect across the Front Range from Denver to the Blue River valley near Dillon, the trip explores the geologic framework and Laramide (Late Cretaceous to early Eocene) uplift history of this basement-cored mountain range. Specific items for discussion at various stops are (1) the sedimentary and structural record...
Structure of the Red Dog District, western Brooks Range, Alaska
Jean-Pierre P. de Vera, K. R. McClay
2004, Economic Geology (99) 1415-1434
The Red Dog district of the western Brooks Range of northern Alaska, which includes the sediment-hosted Zn-Pb-Ag ± Ba deposits at Red Dog, Su-Lik, and Anarraaq, contains one of the world's largest reserves of zinc. This paper presents a new model for the structural development of the area and shows...
Landslides triggered by the 13 January and 13 February 2001 earthquakes in El Salvador
Randall W. Jibson, Anthony J. Crone, Edwin Harp, Rex Baum, Jon J. Major, Carlos Pullinger, C.D. Escobar, Mauricio Martinez, Mark E. Smith
2004, Special Paper of the Geological Society of America (375) 69-88
During a one-month period in early 2001, El Salvador experienced two devastating earthquakes. On 13 January, a M-7.7 earthquake centered ∼40 km off the southern coast in the Pacific Ocean caused widespread damage and fatalities throughout much of the country. The earthquake triggered thousands of landslides that were broadly scattered across the southern half of the...
Debris-flow hazards at San Salvador, San Vicente, and San Miguel volcanoes, El Salvador
Jon J. Major, Steve P. Schilling, Carlos Pullinger, C.D. Escobar
2004, Special Paper of the Geological Society of America (375) 89-108
Volcanic debris flows (lahars) in El Salvador pose a significant risk to tens of thousands of people as well as to property and important infrastructure. Major cities and nearly a third of the country's population are located near San Salvador, San Vicente, and San Miguel volcanoes. Debris flows traveling as...
Stable Isotope Analysis of Water and Aqueous Solutions by Conventional Dual-Inlet Mass Spectrometry
Juske Horita, Carol Kendall
P. A. de Groot, editor(s)
2004, Book chapter, Handbook of stable isotope analytical techniques
This chapter reviews the recent developments and refinements of analytical methods for preparing waters and other aqueous samples of different origins for the measurement of the oxygen and hydrogen isotopes by conventional dual-inlet, dynamic gas-source isotope-ratio mass spectrometry. The emerging techniques of continuous-flow mass-spectrometry are discussed as they are employed...
Hydrology: Chapter D
Claudia C. Faunt, Frank A. D’Agnese, Grady M. O’Brien
Wayne R. Belcher, Donald S. Sweetkind, editor(s)
2004, Book chapter, Death Valley regional groundwater flow system, Nevada and California--hydrogeologic framework and transient groundwater flow model
No abstract available....
Selenium, iron, and chromium stable isotope ratio measurements by the double isotope spike TIMS method
Thomas M. Johnson, Thomas D. Bullen
2004, Book chapter, Handbook of stable isotope analytical techniques
This chapter focuses on the double-spike calibrated thermal ionization mass spectrometry (TIMS) methods for measurement of mass dependent isotope fractionation in Se, Fe, and Cr. Current measurement precision is approximately ± 0.2 per mil on 80Se / 76Se, 56Fe / 54Fe, and 53Cr / 52Cr. Sample size requirements are 500ng, 1μg, and 250ng for Se, Fe,...
Modeling microbial enhancement of Zn (II) and Pb (II) transport in columns packed with geologic media
Lee L. Landkamer, R.W. Harvey, D. W. Metge, J. N. Ryan
Jay R. Alder, R.R. Seal, editor(s)
2004, Book chapter, Water rock interaction
No abstract available....
Evaluating remedial alternatives for the Alamosa River and Wightman Fork, near Summitville Mine, Colorado: Application of a reactive transport model to low- and high-flow simulations
J.W. Ball, R.L. Runkel, D. Kirk Nordstrom
2004, Book chapter, Environmental sciences and environmental computing
Reactive-transport processes in Wightman Fork and the Alamosa River downstream from the SummitvilleMine, south-central Colorado, were simulated at low and high flow using the OTEQ reactive-transport model.The simulations were calibrated using data from synoptic studies conducted during October 1998 and June1999. Discharge over the 30-km reach from just below the...
Seismic history of the Middle America subduction zone along El Salvador, Guatemala, and Chiapas, Mexico: 1526–2000
Randall A. White, Juan Pablo Ligorria, I.L. Cifuentes
William I. Rose, Julian J. Bommer, Dina L. Lopez, Michael J. Carr, Jon J. Major, editor(s)
2004, Book chapter, Natural hazards in El Salvador
We present a catalog of subduction zone earthquakes along the Pacific coast from central El Salvador to eastern Chiapas, Mexico, from 1526 to 2000. We estimate that the catalog is complete since 1690 for MS ≥7.4 thrust events and M ≥ 7.4 normal-faulting events within the upper 60 km of the...
Selenium loading through the Blackfoot River watershed--linking sources to ecosystem
Theresa S. Presser, Matthew Hardy, Mark Huebner, Paul J. Lamothe
James R. Hein, editor(s)
2004, Book chapter, Handbook of exploration and environmental geochemistry
The upper Blackfoot River watershed in southeast Idaho receives drainage from 11 of 16 phosphate mines that have extracted ore from the Phosphoria Formation, three of which are presently active. Toxic effects from selenium (Se), including death of livestock and deformity in aquatic birds, were documented locally in areas...
Fundamental concepts of recharge in the Desert Southwest: A regional modeling perspective
Alan L. Flint, Lorraine E. Flint, J.A. Hevesi
2004, Book chapter, Groundwater recharge in a desert environment: The southwestern United States
Recharge in arid basins does not occur in all years or at all locations within a basin. In the desert Southwest potential evapotranspiration exceeds precipitation on an average annual basis and, in many basins, on an average monthly basis. Ground-water traveltime from the surface to the water table and recharge...
Age and evolution of the Precambrian crust of the Tobacco Root Mountains, Montana
Paul A. Mueller, Henry Robert Burger, Joseph L. Wooden, Ann L. Heatherington, David W. Mogk, Kimberly D’Arcy
John B. Brady, John T. Cheney, Tekla Harms, editor(s)
2004, Book chapter, Precambrian geology of the Tobacco Root Mountains, Montana
U-Pb analyses of zircons from gneisses, anatectic leucosome, metasedimentary rocks, and a younger (metamorphosed) mafic dike from the Tobacco Root Mountains of southwestern Montana document a Precambrian history that extends from at least 3.90–1.77 Ga. The oldest U-Pb age reported here (3.8 Ga) is from a detrital zircon from a...
Designing monitoring programs in an adaptive management context for regional multiple species conservation plans
A.J. Atkinson, P.C. Trenham, Robert N. Fisher, S.A. Hathaway, B.S. Johnson, S.G. Torres, Y.C. Moore
2004, Report
Increasing numbers of regional, multiple species conservation plans have been developed in California since the early 1990s. However, building effective monitoring and adaptive management programs to support these plans has remained a challenge. In addition to collecting data on the status of resources and the results of management actions, monitoring...
Linking surface- and ground-water levels to riparian grassland species along the Platte River in central Nebraska
R.J. Henszey, K. Pfeiffer, J.R. Keough
2004, Wetlands (24) 665-687
Nearly all the techniques used to quantify how plants are linked to environmental gradients produce results in general terms, such as low to high elevation, xeric to mesic, and low to high concentration. While ecologists comprehend these imprecise scales, managers responsible for making decisions affecting these gradients need more precise...
Effects of distance from cattle water developments on grassland birds
A.L. Fontaine, P.L. Kennedy, Douglas H. Johnson
2004, Journal of Range Management (57) 238-242
Many North American grassland bird populations appear to be declining, which may be due to changes in grazing regimes on their breeding areas. Establishment of water developments and confining cattle (Bos taurus L.) to small pastures often minimizes spatial heterogeneity of cattle forage consumption, which may lead to uniformity in...
