Volumetric evolution of Surtsey, Iceland, from topographic maps and scanning airborne laser altimetry
J.B. Garvin, R.S. Williams, J.J. Frawley, W.B. Krabill
2000, Surtsey Research (11) 127-134
The volumetric evolution of Surtsey has been estimated on the basis of digital elevation models derived from NASA scanning airborne laser altimeter surveys (20 July 1998), as well as digitized 1:5,000-scale topographic maps produced by the National Land Survey of Iceland and by Norrman. Subaerial volumes have been computed from...
Advances in the hydrogeochemistry and microbiology of acid mine waters
D. Kirk Nordstrom
2000, International Geology Review (42) 499-515
The last decade has witnessed a plethora of research related to the hydrogeochemistry and microbiology of acid mine waters and associated tailings and waste-rock waters. Numerous books, reviews, technical papers, and proceedings have been published that examine the complex bio-geochemical process of sulfide mineral oxidation, develop and apply geochemical models...
Geological monitoring of Surtsey, Iceland, 1967-1998
Sveinn P. Jakobsson, Gudmundur Gudmundsson, James G. Moore
2000, Surtsey Research (11) 99-108
Aspects of the geological monitoring of the volcanic island of Surtsey 1967-1998, are described. A hydrothermal system was developed within the tephra craters in late 1966 to early 1967. Temperatures in a drill hole, situated at the eastern border of the hydrothermal area, indicate that the hydrothermal system at that...
Applications of imaging spectroscopy data: A case study at Summitville, Colorado
Trude King, Roger N. Clark, Gregg A. Swayze
2000, Book chapter, Remote sensing for site characterization
From 1985 through 1992, the Summitville open-pit mine produced gold from lowgrade ore using cyanide heap-leach techniques, a method to extract gold whereby the ore pile is sprayed with water containing cyanide, which dissolves the minute gold grains. Environmental problems due to mining activity at Summitville include significant increases in...
Evaluating temporal changes in stream condition in three New Jersey rive basins by using an index of biotic integrity
Ming Chang, Jonathan G. Kennen, Ellyn Del Corso
2000, Bulletin of the New Jersey Academy of Science (45) 1-12
An index of biotic integrity (!B!) modified for New Jersey streams was used to compare changes in stream condition from the 1970s to the 1990s in Delaware, Passaic, and Raritan River Basins. Stream condition was assessed at 88 sampling locations. Mean IBI scores for all basins increased from the 1970s...
Two-phase debris-flow across 3-D terrain: model predictions and experimental tests
R.M. Iverson, R.P. Denlinger, R.G. LaHusen, M. Logan
2000, Book, Proceedings of the Third International Conference on Debris-Flow Hazards Mitigation
No abstract available....
Growth in conventional fields in high-cost areas: A case study
Emil Attanasi
2000, World Oil (221) 63-66
Exploration managers commonly base future drilling decisions on past experience in an area. To do this well, they should consider both discovered and undiscovered resources to characterize total future potential. Discovery-size estimates should be adjusted to account for future field growth; otherwise, the relative efficiency of recent exploration will be...
The derivation of World Magnetic Model 2000
Susan Macmillan, John M. Quinn
2000, British Geological Survey Technical Report WM/00/17R
This report contains a detailed summary of the data used, the modelling techniques employed and the results obtained in the production of the World Magnetic Model 2000. This model is designed for use in air and sea navigation systems and is valid till 2005.0. The derivation of World Magnetic Model...
Hydrologic and geologic characteristics of the Yucca Mountain site relevant to the performance of a potential repository: Day 1, Las Vegas, Nevada to Pahrump, Nevada: Stop 6A. Keane Wonder Spring and regional groundwater flow in the Death Valley region
W.C. Steinkampf
2000, GSA Field Guides (2) 398-398
Yucca Mountain, located ~100 mi northwest of Las Vegas, Nevada, has been designated by Congress as a site to be characterized for a potential mined geologic repository for high-level radioactive waste. This field trip will examine the regional geologic and hydrologic setting for Yucca Mountain, as well as specific results...
Application of snow models to snow removal operations on the Going-to-the-Sun Road, Glacier National Park
Daniel B. Fagre, Frederick L. Klasner
2000, Book, Proceedings of the 2000 International Snow Science Workshop
Snow removal, and the attendant avalanche risk for road crews, is a major issue on mountain highways worldwide. The Going-to-the-Sun Road is the only road that crosses Glacier National Park, Montana. This 80-km highway ascends over 1200m along the wall of a glaciated basin and crosses the continental divide. The...
High-temperature quartz cement and the role of stylolites in a deep gas reservoir, Spiro Sandstone, Arkoma Basin, USA
Richard H. Worden, Sadoon Morad, C. Spotl, D.W. Houseknecht, L.R. Riciputi
2000, Book chapter, Quartz cementation in sandstones
The Spiro Sandstone, a natural gas play in the central Arkoma Basin and the frontal Ouachita Mountains preserves excellent porosity in chloritic channel-fill sandstones despite thermal maturity levels corresponding to incipient metamorphism. Some wells, however, show variable proportions of a late-stage, non-syntaxial quartz cement, which post-dated thermal cracking of liquid...
Isotopic studies of authigenic sulfides, silicates and carbonates, and calcite and pyrite veinlets in the Creede Formation, San Juan Mountains, Southwest Colorado
Philip M. Bethke, Robert O. Rye, David B. Finkelstein
2000, GSA Special Papers (346) 267-286
Sulfur isotope analysis of authigenic pyrite in the Creede Formation documents its precipitation by the reaction between iron in the volcaniclastic sediments and H2S formed through bacteriogenic reduction of sulfate added to the lake during and immediately following repeated volcanic eruptions during sedimentation. Pyrite veinlets in the underlying Snowshoe Mountain...
Overview: Ancient Lake Creede
Philip M. Bethke, Richard L. Hay
2000, GSA Special Papers (346) 1-8
Lake Creede was moderately saline closed-basin lake that developed in the 26.9 Ma Creede caldera in the San Juan Mountains in the southwest Colorado. The volcaniclastic sediments deposited within the late Oligocene lake were first described and named as the Creede Formation by Emmons and Larsen (1923). The lake and...
Hydrologic budget of the late Oligocene Lake Creede and the evolution of the upper Rio Grande drainage system
Paul B. Barton, Thomas A. Steven, Daniel O. Hayba
2000, GSA Special Papers (346) 105-126
The filling history, hydrologic budget, and geomorphic development of ancient Lake Creede and its tributary basin are evaluated to determine the factors that controlled its character. The lake filled the Creede caldera that formed in the late Oligocene as a consequence of the eruption of the Snowshoe Mountain Tuff. The...
Neogene geomorphic and climatic evolution of the central San Juan Mountains, Colorado: K/Ar age and stable isotope data on supergene alunite and jarosite from the Creede mining district
Robert O. Rye, Philip M. Bethke, Marvin A. Lanphere, Thomas A. Steven
2000, GSA Special Papers (346) 95-103
K/Ar age determinations or supergene alunite and jarosite, formed during Neogene weathering of the epithermal silver and base-metal ores of the Creede mining district, have been combined with geologic evidence to estimate the timing of regional uplift of the southern Rocky Mountains and related canyon cutting. In addition, oxygen and...
Landslides and tsunamis
Christopher F. Waythomas, Alastair G. Dawson
Barbara H. Keating, Christopher F. Waythomas, Alastair G. Dawson, editor(s)
2000, Book, Pure and Applied Geophysics
The study of tsunamis has been shifting away from theoretical modeling of tsunami source, wave propagation and runup toward multidisciplinary investigations, with an emphasis on field studies. This collection of papers highlights the many approaches being utilized to study landslides and tsunamis....
Evolution of the Creede Caldera and its relation to mineralization in the Creede mining district, Colorado
Paul B. Barton, Robert O. Rye, Philip M. Bethke
2000, GSA Special Papers (346) 301-326
At 25 Ma a major epithermal silver and base metal deposit formed in rhyolitic welded tuff near Creede, Colorado. Nearly 24000 metric tons of silver, appreciable lead, and small amounts of zinc, copper, and gold, have been produced from large, crustified veins under Bachelor and Bulldog Mountains north and northwest...
SHRIMP U-Pb zircon ages for Big Creek gneiss, Wyoming and Boulder Creek batholith, Colorado: Implications for timing of Paleoproterozoic accretion of the northern Colorado province
Wayne R. Premo, C. Mark Fanning
2000, Rocky Mountain Geology (35) 31-50
Sensitive, high-resolution, ion microprobe (SHRIMP) U-Pb zircon ages from a sample of the high-grade, hornblende-feldspathic Big Creek gneiss of the southeastern Sierra Madre, along with samples of a quartz monzonitic phase of the Boulder Creek batholith, help define timing of three major Paleoproterozoic thermo-tectonic events within the northern Colorado province...
Modeling surface-subsurface hydrological interactions
Aaron I. Packman, Kenneth E. Bencala
Jeremy B. Jones, Patrick J. Mulholland, editor(s)
2000, Book chapter, Streams and ground waters
Emergent biological patterns and surface-subsurface interactions at landscape scales
C. M. Pringle, F.J. Triska
Jeremy B. Jones, Patrick J. Mulholland, editor(s)
2000, Book chapter, Streams and ground waters
In this chapter, we focus on emergent biological patterns in riverine ecosystems at landscape scales resulting from surface-subsurface water interaction. Our objectives are to examine (1) how the balance of physical and chemical factors on the "natural" geologic template affects biological patterns, (2) how natural hydrothermal systems can be used...
Vegetation and soils
M.K. Burke, S.L. King, M.H. Eisenbies, D. Gartner
2000, Book chapter, The Coosawhatchie Bottomland Ecosystem Study: a report on the development of a reference wetland
haracterization of bottomland hardwood vegetation in relatively undisturbed forests can provide critical information for developing effective wetland creation and restoration techniques and for assessing the impacts of management and development. Classification is a useful technique in characterizing vegetation because it summarizes complex data sets, assists in hypothesis generation about factors...
Condition bias of hunter-shot ring-necked ducks exposed to lead
K. G. McCracken, A. D. Afton, M.S. Peters
2000, Journal of Wildlife Management (64) 584-590
We evaluated the condition bias hypothesis for ring-necked ducks (Aythya collaris) exposed to lead by testing the null hypothesis that ducks shot by hunters do not differ in physiological condition from those collected randomly from the same location. After adjusting for structural body size and log(e) concentration of blood lead,...
Estimating formation properties from early-time oscillatory water levels in a pumped well
A.M. Shapiro, D.S. Oki
2000, Journal of Hydrology (236) 91-108
Hydrologists often attempt to estimate formation properties from aquifer tests for which only the hydraulic responses in a pumped well are available. Borehole storage, turbulent head losses, and borehole skin, however, can mask the hydraulic behavior of the formation inferred from the water level in the pumped well. Also, in...
Septicemic pasteurellosis in free-ranging neonatal pronghorn in Oregon
Michael R. Dunbar, Mark J. Wolcott, R.B. Rimler, Brenda M. Berlowski
2000, Journal of Wildlife Diseases (36) 383-388
As part of a study to determine the cause(s) of population decline and low survival of pronghorn (Antilocapra americana) neonates on Hart Mountain National Antelope Refuge (HMNAR), Oregon (USA), 55 of 104 neonates captured during May 1996 and 1997 were necropsied (n = 28, 1996; n = 27, 1997) to...
Strain accumulation along the Cascadia subduction zone
M.H. Murray, M. Lisowski
2000, Geophysical Research Letters (27) 3631-3634
We combine triangulation, trilateration, and GPS observations to determine horizontal strain rates along the Cascadia subduction zone from Cape Mendocino to the Strait of Juan de Fuca. Shear-strain rates are significantly greater than zero (95% confidence) in all forearc regions (26-167 nanoradians/yr), and are not significant in the arc and...
