Geologic time
William L. Newman
2000, Report
The Earth is very old 4 1/2 billion years or more according to recent estimates. This vast span of time, called geologic time by earth scientists, is difficult to comprehend in the familiar time units of months and years, or even centuries. How then do scientists reckon geologic time, and...
Prodigious polyphyly in imperilled freshwater pearly-mussels (Bivalvia: Unionidae): a phylogenetic test of species and generic designations
Charles Lydeard, Russell L. Minton, James D. Williams
2000, Geological Society Special Publication (177) 145-158
Unionid bivalves or freshwater pearly-mussels (Unionoidea: Unionidae) serve as an exemplary system for examining many of the problems facing systematists and conservation biologists today. Most of the species and genera were described in the late 1800s and early 1900s, but few phylogenetic studies have been conducted to test conventional views...
Superposed fold-thrust events at the Nevada Test Site
Patricia H. Cashman, J. C. Cole, James H. Trexler Jr.
2000, GSA Field Guides (2) 337-354
The Nevada Test Site (NTS), in southern Nye County, Nevada, straddles significant pre-Tertiary structural and stratigraphic boundaries. Detailed stratigraphy and biostratigraphy of the Upper Paleozoic section delineates the regional trust sheets and constrains their burial histories. The Paleozoic rocks record three phases of contractional deformation, overprinted by strike-slip faulting. These...
Nitrogen biogeochemistry and surface-subsurface exchange in streams
John H. Duff, Frank J. Triska
Jeremy B. Jones, Patrick J. Mulholland, editor(s)
2000, Book chapter, Streams and ground waters
No abstract available. ...
Regional versus floodplain perspectives on flood management in the Upper Mississippi River Basin
Gary E. Freeman, Ann G. Frazier, John A. Kelmelis
2000, Book chapter, Selected studies on natural and human factors related to flood management in the Upper Mississippi River Basin
No abstract available....
Can contaminant transport models predict breakthrough?
Wei-Shyuan Peng, Duane R. Hampton, Leonard F. Konikow, Kiran Kambham, Jeffery J. Benegar
2000, Groundwater Monitoring & Remediation (20) 104-113
A solute breakthrough curve measured during a two-well tracer test was successfully predicted in 1986 using specialized contaminant transport models. Water was injected into a confined, unconsolidated sand aquifer and pumped out 125 feet (38.3 m) away at the same steady rate. The injected water was spiked with bromide for...
Remote sensing for site characterization
Friedrich Kuehn, Trude V. King, Bernhard Hoerig, Douglas C. Peters
Friedrich Kuehn, Trude V. King, Bernhard Hoerig, Douglas C. Peters, editor(s)
2000, Book, Methods in environmental geology
This volume, Remote Sensing for Site Characterization, describes the feasibility of aircraft- and satellite-based methods of revealing environmental-geological problems. A balanced ratio between explanations of the methodological/technical side and presentations of case studies is maintained. The comparison of case studies from North America and Germany show how the respective territorial...
Selected studies on natural and human factors related to flood management in the Upper Mississippi River Basin
Ann G. Frazier, Gary E. Freeman
2000, Book, Science for floodplain management into the 21st century
No abstract available....
Late Cenozoic crustal extension and magmatism, southern Death Valley region, California
J.P. Calzia, O.T. Ramo
2000, GSA Field Guides (2) 135-164
The late Cenozoic geologic history of the southern Death Valley region is characterized by coeval crustal extension and magamatism. Crustal extension is accommodated by numerous listric and planar normal faults as well as right- and left-lateral strike slip faults. The normal faults sip 30°-50° near the surface and flatten and...
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...
Paleozoic subduction complex and Paleozoic-Mesozoic island-arc volcano-plutonic assemblages in the northern Sierra terrane
Richard E. Hanson, Gary H. Girty, David S. Harwood, Richard A. Schweickert
2000, GSA Field Guides (2) 255-277
This field trip provides an overview of the stratigraphic and structural evolution of the northern Sierra terrane, which forms a significant part of the wall rocks on the western side of the later Mesozoic Sierra Nevada batholith in California. The terrane consists of a pre-Late Devonian subduction complex (Shoo Fly...
TES observations of the martian surface and atmosphere
P. R. Christensen, H. H. Kieffer, J.C. Pearl, B. Conrath, M. C. Malin, R.C. Clark, R.V. Morris, J.L. Banfield, M. D. Lane, M. D. Smith, V.E. Hamilton, R.O. Kuzmin
2000, Book, Second International Conference on Mars Polar Science and Exploration
The TES instrument is a Fourier transform Michelson interferometer operating with 10 or 5 cm-1 sampling int he thermal infared spectral region from 1700 to 200 cm-1 (~6 to 50 μm) where virtually all minerals have characteristic fundamental vibrational absorption bands (1, 2, 3, 4, 5, 6, 7, 8). The...
The value of long-term streamflow records
J. M. Norris
2000, Water Resources Impact (2) 11-14
No abstract available....
An elevational gradient in snowpack chemical loading at Glacier National Park, Montana: implications for ecosystem processes
Daniel Fagre, Kathy Tonnessen, Kristi Morris, George Ingersoll, Lisa McKeon, Karen Holzer
2000, Conference Paper, Proceedings of the 2000 International Snow Science Workshop
The accumulation and melting of mountain snowpacks are major drivers of ecosystem processes in the Rocky Mountains. These include the influence of snow water equivalent (SWE) timing and amount of release on soil moisture for annual tree growth, and alpine stream discharge and temperature that control aquatic biota life histories....
Data for Quaternary faults in western Montana
Kathleen M. Haller, Richard L. Dart, Michael N. Machette, Michael C. Stickney
2000, Open-File Report 2000-411
The "World Map of Major Active Faults" Task Group is compiling published fault data, developing a digital database of the fault data, and preparing a series of maps for the United States and other countries in the western Hemisphere. The data is intended to portray the locations, ages, and activity rates of...
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...
A preliminary re-evaluation of the stratigraphy of the Roubidoux Formation of Missouri and correlative Lower Ordovician units in the southern midcontinent
J.E. Repetski, James D. Loch, Raymond L. Ethington, R.I. Dresbach
2000, Book, Platform carbonates in the southern midcontinent, 1996 symposium: proceedings of a symposium held March 26-27, 1996, in Oklahoma City
No abstract available....
Central San Juan caldera cluster: Regional volcanic framework
Peter W. Lipman
2000, GSA Special Papers (346) 9-69
Eruption of at least 8800 km3 of dacitic-rhyolitic magma as 9 major ash-slow sheets (individually 150-5000 km3) was accompanied by recurrent caldera subsidence between 28.3 and about 26.5 Ma in the central San Juan Mountains, Colorado. Voluminous andesitic-decitic lavas and breccias were erupted from central volcanoes prior to the ash-flow...
Flow of nitrogen into Mississippi Basin believed to cause Gulf hypoxia
Donald A. Goolsby
2000, Earth in Space (13) 6-10
No abstract available....
Near surface infiltration monitoring neutron moisture logging, Yucca Mountain, Nevada
A. L. Flint, L. E. Flint
2000, Book chapter, Vadose zone science and technology solutions
No abstract available....
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...
The Edwards Aquifer Authority and U.S. Geological Survey Water Resources Program Quarterly Report- 04/01/2000 to 07/31/2000
2000, Report
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...
IFR enroute low altitude
United States.
2000, Report
No abstract available....
