Ge/Si and 87Sr/86Sr tracers of weathering reactions and hydrologic pathways in a tropical granitoid system
L.A. Derry, J. C. Pett-Ridge, A.C. Kurtz, J.W. Troester
2006, Journal of Geochemical Exploration (88) 271-274
Ge/Si and 87Sr/86Sr data from primary and secondary minerals, soil waters, and stream waters in a tropical granitoid catchment quantitatively reflect mineral alteration reactions that occur at different levels within the bedrock-saprolite-soil zone. Near the bedrock-saprolite interface, plagioclase to kaolinite reaction yields low Ge/Si and 87Sr/86Sr. Higher in the regolith...
Effect of H2 and redox condition on biotic and abiotic MTBE transformation
P. M. Bradley, F. H. Chapelle, J. E. Landmeyer
2006, Ground Water Monitoring and Remediation (26) 74-81
Laboratory studies conducted with surface water sediment from a methyl tert-butyl ether (MTBE)-contaminated site in South Carolina demonstrated that, under methanogenic conditions, [U-14C] MTBE was transformed to 14C tert-butyl alcohol (TBA) with no measurable production of 14CO2. Production of TBA was not attributed to the activity of methanogenic microorganisms, however,...
Inverse modeling for seawater intrusion in coastal aquifers: Insights about parameter sensitivities, variances, correlations and estimation procedures derived from the Henry problem
E. Sanz, C.I. Voss
2006, Advances in Water Resources (29) 439-457
Inverse modeling studies employing data collected from the classic Henry seawater intrusion problem give insight into several important aspects of inverse modeling of seawater intrusion problems and effective measurement strategies for estimation of parameters for seawater intrusion. Despite the simplicity of the Henry problem, it embodies the behavior of a...
Recharge processes drive sulfate reduction in an alluvial aquifer contaminated with landfill leachate
M. A. Scholl, I.M. Cozzarelli, S. C. Christenson
2006, Journal of Contaminant Hydrology (86) 239-261
Natural attenuation of contaminants in groundwater depends on an adequate supply of electron acceptors to stimulate biodegradation. In an alluvial aquifer contaminated with leachate from an unlined municipal landfill, the mechanism of recharge infiltration was investigated as a source of electron acceptors. Water samples were collected monthly at closely spaced intervals...
Effects of permafrost melting on CO2 and CH4 exchange of a poorly drained black spruce lowland
K.P. Wickland, Robert G. Striegl, J. C. Neff, T. Sachs
2006, Journal of Geophysical Research G: Biogeosciences (111)
[1] Permafrost melting is occurring in areas of the boreal forest region where large amounts of carbon (C) are stored in organic soils. We measured soil respiration, net CO2 flux, and net CH4 flux during May–September 2003 and March 2004 in a black spruce lowland in interior Alaska to...
From agricultural geology to hydropedology: Forging links within the twenty-first-century geoscience community
E. R. Landa
Frossard E.Blum W.E.H.Warkentin B.P., editor(s)
2006, Geological Society Special Publication 133-140
Despite historical linkages, the fields of geology and soil science have developed along largely divergent paths in the United States during much of the mid- to late-twentieth century. The shift in recent decades within both disciplines, towards greater emphasis on environmental-quality issues and a systems approach, has created new opportunities...
Water-quality characteristics and contaminants in the rural karst-dominated Spring Mill Lake watershed, southern Indiana
N.R. Hasenmueller, M.A. Buehler, N.C. Krothe, J.B. Comer, T.D. Branam, M.V. Ennis, R.T. Smith, D.D. Zamani, L. Hahn, J.P. Rybarczyk
2006, Special Paper of the Geological Society of America 153-167
The Spring Mill Lake watershed is located in the Mitchell Plateau, a karst area that developed on Mississippian carbonates in southern Indiana. Spring Mill Lake is a reservoir built in the late 1930s and is located in Spring Mill State Park. Within the park, groundwater from subsurface conduits issues as...
Geology of the Yucca Mountain region
J. S. Stuckless, Dennis W. O’Leary
2006, Memoir of the Geological Society of America (199) 9-50
Yucca Mountain has been proposed as the site for the nation's first geologic repository for high-level radioactive waste. This chapter provides the geologic framework for the Yucca Mountain region. The regional geologic units range in age from late Precambrian through Holocene, and these are described briefly. Yucca Mountain is composed...
Enantiomeric separation of metolachlor and its metabolites using LC-MS and CZE
C. John Klein, R.J. Schneider, M. T. Meyer, D.S. Aga
2006, Chemosphere (62) 1591-1599
The stereoisomers of metolachlor and its two polar metabolites [ethane sulfonic acid (ESA) and oxanilic acid (OXA)] were separated using liquid chromatography–mass spectrometry (LC–MS) and capillary zone electrophoresis (CZE), respectively. The separation of metolachlor enantiomers was achieved using a LC–MS equipped with a...
Kinetics of sorption and abiotic oxidation of arsenic(III) by aquifer materials
A. Amirbahman, D.B. Kent, G.P. Curtis, J.A. Davis
2006, Geochimica et Cosmochimica Acta (70) 533-547
The fate of arsenic in groundwater depends largely on its interaction with mineral surfaces. We investigated the kinetics of As(III) oxidation by aquifer materials collected from the USGS research site at Cape Cod, MA, USA, by conducting laboratory experiments. Five different solid samples with similar specific surface areas (0.6–0.9 m2 g−1) and...
Towards sustainable management of Louisiana's coastal wetland forests: Problems, constraints, and a new beginning
J. L. Chambers, W.H. Conner, R.F. Keim, S.P. Faulkner, J.W. Day, E.S. Gardiner, M.S. Hughes, S.L. King, K.W. McLeod, C.A. Miller, J.A. Nyman, G.P. Shaffer
2006, Conference Paper, Hydrology and management of forested wetlands - Proceeding of the international conference
Over 345,000 ha of forested swamps occur throughout the Mississippi River Deltaic Plain. Natural and anthropogenic changes in hydrology and geomorphology at local and landscape levels have reduced the productivity in many of these coastal wetland forests areas and have caused the complete loss of forest cover in some places....
Measuring permanence of CO2 storage in saline formations: The Frio experiment
Susan D. Hovorka, Sally M. Benson, Christine Doughty, Barry M. Freifeild, Shinichi Sakurai, Thomas M. Daley, Yousif K. Kharaka, Mark H. Holtz, Robert C. Trautz, H. Seay Nance, Larry R. Myer, Kevin G. Knauss
2006, Environmental Geosciences (13) 105-121
If CO2 released from fossil fuel during energy production is returned to the subsurface, will it be retained for periods of time significant enough to benefit the atmosphere? Can trapping be assured in saline formations where there is no history of hydrocarbon accumulation? The Frio experiment in Texas was...
Increasing streamflow and baseflow in Mississippi River since the 1940 s: Effect of land use change
Y.-K. Zhang, K. E. Schilling
2006, Journal of Hydrology (324) 412-422
A trend of increasing streamflow has been observed in the Mississippi River (MR) basin since the 1940 s as a result of increased precipitation. Herein we show that increasing MR flow is mainly in its baseflow as a result of land use change and accompanying agricultural activities that occurred in...
Geochemistry of low-temperature springs northwest of Yellowstone caldera: Seeking the link between seismicity, deformation, and fluid flow
William C. Evans, Deborah Bergfeld, Matthias C. van Soest, Mark Huebner, John Fitzpatrick, Kinga M. Revesz
2006, Journal of Volcanology and Geothermal Research (154) 169-180
A comprehensive geochemical survey of springs outside the northwest margin of the Yellowstone caldera was undertaken in 2003 and 2004. This survey was designed to detect: (1) active leakage from a huge reservoir of CO2 gas recently postulated to extend from beneath the caldera into this area; and (2) lingering evidence...
Effects of long-term water table drawdown on evapotranspiration and vegetation in an arid region phreatophyte community
D.J. Cooper, J.S. Sanderson, D.I. Stannard, D.P. Groeneveld
2006, Journal of Hydrology (325) 21-34
Evapotranspiration rates and the ground water component of evapotranspiration at a site in Colorado's San Luis Valley that is dominated by shrubby phreatophytes (greasewood and rabbitbrush) were compared before and after a water table drawdown. Evapotranspiration (ET) rates at the site were first measured in 1985-1987 (pre-drawdown) when the mean...
A 16-year record of eolian dust in Southern Nevada and California, USA: Controls on dust generation and accumulation
M.C. Reheis
2006, Journal of Arid Environments (67) 487-520
An ongoing project monitors modern dust accumulation in the arid southwestern United States to (1) determine the rate and composition of dust inputs to soils and (2) relate dust accumulation to weather patterns to help predict the effects of climate change on dust production and accumulation. The 16-year records of...
Use of borehole radar tomography to monitor steam injection in fractured limestone
C. Gregoire, P. K. Joesten
2006, Near Surface Geophysics (4) 355-365
Borehole radar tomography was used as part of a pilot study to monitor steam‐enhanced remediation of a fractured limestone contaminated with volatile organic compounds at the former Loring Air Force Base, Maine, USA. Radar tomography data were collected using 100‐MHz electric‐dipole antennae before and during steam injection to evaluate whether...
Testing of stack-unit/aquifer sensitivity analysis using contaminant plume distribution in the subsurface of Savannah River Site, South Carolina, USA
J.M. Rine, J.M. Shafer, E. Covington, R. C. Berg
2006, Hydrogeology Journal (14) 1620-1634
Published information on the correlation and field-testing of the technique of stack-unit/aquifer sensitivity mapping with documented subsurface contaminant plumes is rare. The inherent characteristic of stack-unit mapping, which makes it a superior technique to other analyses that amalgamate data, is the ability to deconstruct the sensitivity analysis on a unit-by-unit...
Modeling the influence of river rehabilitation scenarios on bed material sediment flux in a large river over decadal timescales
Michael B. Singer, Thomas Dunne
2006, Water Resources Research (42)
A stochastic flood generator and calibrated sediment transport formulae were used to assess the decadal impact of major river rehabilitation strategies on two fraction bed material sediment flux and net storage, first‐order indicators of aquatic riverine habitat, in a large river system. Model boundary conditions were modified to reflect the...
Hyporheic exchange and fulvic acid redox reactions in an alpine stream/wetland ecosystem, Colorado front range
Matthew P. Miller, Diane M. McKnight, R.M. Cory, Mark W. Williams, Robert L. Runkel
2006, Environmental Science & Technology (40) 5943-5949
The influence of hyporheic zone interactions on the redox state of fulvic acids and other redox active species was investigated in an alpine stream and adjacent wetland, which is a more reducing environment. A tracer injection experiment using bromide (Br-) was conducted in the stream system. Simulations...
Late Holocene lake-level fluctuations in Walker Lake, Nevada, USA
F. Yuan, B.K. Linsley, S. S. Howe, S.P. Lund, J. P. McGeehin
2006, Palaeogeography, Palaeoclimatology, Palaeoecology (240) 497-507
Walker Lake, a hydrologically closed, saline, and alkaline lake, is situated along the western margin of the Great Basin in Nevada of the western United States. Analyses of the magnetic susceptibility (??), total inorganic carbon (TIC), and oxygen isotopic composition (??18O) of carbonate sediments including ostracode shells (Limnocythere ceriotuberosa) from...
Possible linkages between lignite aquifers, pathogenic microbes, and renal pelvic cancer in northwestern Louisiana, USA
J.E. Bunnell, C. A. Tatu, R.N. Bushon, D. M. Stoeckel, A.M.G. Brady, M. Beck, H.E. Lerch, B. McGee, B.C. Hanson, R. Shi, W. H. Orem
2006, Environmental Geochemistry and Health (28) 577-587
In May and September, 2002, 14 private residential drinking water wells, one dewatering well at a lignite mine, eight surface water sites, and lignite from an active coal mine were sampled in five Parishes of northwestern Louisiana, USA. Using a geographic information system (GIS), wells were selected that were likely...
The hydrology of northern peatlands as affected by biogenic gas: Current developments and research needs
D.O. Rosenberry, P.H. Glaser, D. I. Siegel
2006, Hydrological Processes (20) 3601-3610
Recent research indicates that accumulation and release of biogenic gas from northern peatlands may substantially affect future climate. Sudden release of free-phase gas bubbles into the atmosphere may preclude the conversion of methane to carbon dioxide in the uppermost oxic layer of the peat, resulting in greater contribution of methane...
Translating CFC-based piston ages into probability density functions of ground-water age in karst
Andrew J. Long, L.D. Putnam
2006, Journal of Hydrology (330) 735-747
Temporal age distributions are equivalent to probability density functions (PDFs) of transit time. The type and shape of a PDF provides important information related to ground-water mixing at the well or spring and the complex nature of flow networks in karst aquifers. Chlorofluorocarbon (CFC) concentrations measured for samples from 12...
Michigan Water Year 2005
S. P. Blumer, C.R. Whited, J.M. Ellis, R. J. Minnerick, R.L. LeuVoy
2006, Water Resources Data MI-05-1
This volume of the annual hydrologic data report of Michigan is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey's surface- and ground-water data-collection networks in each state, Puerto Rico, and the Trust Territories. These records of streamflow, ground-water levels, and quality...
