Application of ground-penetrating radar, digital optical borehole images, and cores for characterization of porosity hydraulic conductivity and paleokarst in the Biscayne aquifer, southeastern Florida, USA
K.J. Cunningham
2004, Journal of Applied Geophysics (55) 61-76
This paper presents examples of ground-penetrating radar (GPR) data from two study sites in southeastern Florida where karstic Pleistocene platform carbonates that comprise the unconfined Biscayne aquifer were imaged. Important features shown on resultant GPR profiles include: (1) upward and lateral qualitative interpretative distribution of porosity and hydraulic conductivity; (2)...
Carbonate sediment deposits on the reef front around Oahu, Hawaii
M. A. Hampton, C.T. Blay, C.J. Murray
2004, Marine Georesources and Geotechnology (22) 65-102
Large sediment deposits on the reff front around Oahu are a possible resource for replenishing eroded beaches. High-resolution subbottom profiles clearly depict the deposits in three study areas: Kailua Bay off the windward coast, Makua to Kahe Point off the leeward coast, and Camp Erdman to Waimea off the north...
Isotopic, geochemical, and temporal characterization of Proterozoic basement rocks in the Quitovac region, northwestern Sonora, Mexico: Implications for the reconstruction of the southwestern margin of Laurentia
A. Iriondo, W. R. Premo, Luis M. Martinez-Torres, J. R. Budahn, William W. Atkinson Jr., D. F. Siems, B. Guaras-Gonzalez
2004, Geological Society of America Bulletin (116) 154-170
A detailed geochemical characterization of 19 representative Proterozoic basement rocks in the Quitovac region in northwestern Sonora, Mexico, has identified two distinct Paleoproterozoic basement blocks that coincide spatially with the previously proposed Caborca and "North America" blocks. New U-Pb zircon geochronology revises their age ranges, the Caborca (1.78-1.69 Ga) and...
Oxidized sulfur-rich mafic magma at Mount Pinatubo, Philippines
J.C.M. de Hoog, K.H. Hattori, R. Hoblitt
2004, Contributions to Mineralogy and Petrology (146) 750-761
Basaltic fragments enclosed in andesitic dome lavas and pyroclastic flows erupted during the early stages of the 1991 eruption of Mount Pinatubo, Philippines, contain amphiboles that crystallized during the injection of mafic magma into a dacitic magma body. The amphiboles contain abundant melt inclusions, which recorded the mixing of andesitic...
Influence of natural organic matter source on copper speciation as demonstrated by Cu binding to fish gills, by ion selective electrode, and by DGT gel sampler
C.D. Luider, John Crusius, R.C. Playle, P.J. Curtis
2004, Environmental Science & Technology (38) 2865-2872
Rainbow trout (Oncorhynchus mykiss, 2 g) were exposed to 0−5 μM total copper in ion-poor water for 3 h in the presence or absence of 10 mg C/L of qualitatively different natural organic matter (NOM) derived from water spanning a large gradient in hydrologic residence time. Accumulation of Cu by...
Delineation of tectonic provinces of New York state as a component of seismic-hazard evaluation
R.H. Fakundiny
2004, Northeastern Geology and Environmental Sciences (26) 142-173
Seismic-hazard evaluations in the eastern United States must be based on interpretations of the composition and form of Proterozoic basement-rock terranes and overlying Paleozoic strata, and on factors that can cause relative movements among their units, rather than Phanerozoic orogenic structures, which may be independent of modern tectonics. The tectonic-province...
Transient Analysis of the Source of Water to Wells: Cape Cod, Massachusetts
John P. Masterson, D. A. Walter, D.R. LeBlanc
2004, Ground Water (42) 126-134
A transient flow modeling analysis for potential public-supply wells on western Cape Cod, Massachusetts, demonstrates the difference between transient and steady-state recharge areas can have important implications for wellhead protection. An example of a single pumping well illustrates that commonly, used steady-state time-related capture areas do not represent the recharge...
Comparison of USGS and DLR topographic models of Comet Borrelly and photometric applications
Randolph L. Kirk, Elpitha Howington-Kraus, Laurence A. Soderblom, Bernd Giese, Jurgen Oberst
2004, Icarus (167) 54-69
Stereo analysis of images obtained during the 2001 flyby of Comet Borrelly by NASA's Deep Space 1 (DS1) probe allows us to quantify the shape and photometric behavior of the nucleus. The shape is complex, with planar facets corresponding to the dark, mottled regions of the surface whereas the bright, smooth regions are convexly curved. The...
Comparison of some sediment-hosted, stratiform barite deposits in China, the United States, and India
S. H. B. Clark, F. G. Poole, Z. Wang
2004, Ore Geology Reviews (24) 85-101
Shifts in world barite production since the 1980s have resulted in China becoming the world's largest barite-producing country followed by the US and India. Most barite produced for use in drilling fluids is derived from black shale- and chert-hosted, stratiform marine deposits. In China, Late Proterozoic to Early Cambrian marine...
Acute salt marsh dieback in the Mississippi River deltaic plain: A drought-induced phenomenon?
K.L. McKee, I.A. Mendelssohn, M.D. Materne
2004, Global Ecology and Biogeography (13) 65-73
Aims Extensive dieback of salt marsh dominated by the perennial grass Spartina alterniflora occurred throughout the Mississippi River deltaic plain during 2000. More than 100,000 ha were affected, with 43,000 ha severely damaged. The aim of this work was to determine if sudden dieback could have been caused by a...
Reconstruction of the Upper Jurassic Morrison Formation extinct ecosystem - A synthesis
C.E. Turner, F. Peterson
2004, Sedimentary Geology (167) 309-355
A synthesis of recent and previous studies of the Morrison Formation and related beds, in the context of a conceptual climatic/hydrologic framework, permits reconstruction of the Late Jurassic dinosaurian ecosystem throughout the Western Interior of the United States and Canada. Climate models and geologic evidence indicate that a dry climate...
Marine-target craters on Mars? An assessment study
J. Ormo, J. M. Dohm, J.C. Ferris, A. Lepinette, A.G. Fairen
2004, Meteoritics and Planetary Science (39) 333-346
Observations of impact craters on Earth show that a water column at the target strongly influences lithology and morphology of the resultant crater. The degree of influence varies with the target water depth and impactor diameter. Morphological features detectable in satellite imagery include a concentric shape with an inner crater...
Observed and simulated ground motions in the San Bernardino basin region for the Hector Mine, California, earthquake
R.W. Graves, D.J. Wald
2004, Bulletin of the Seismological Society of America (94) 131-146
During the MW 7.1 Hector Mine earthquake, peak ground velocities recorded at sites in the central San Bernardino basin region were up to 2 times larger and had significantly longer durations of strong shaking than sites just outside the basin. To better understand the effects of 3D structure on the...
Revisiting the 23 February 1892 Laguna Salada earthquake
S. E. Hough, A. Elliot
2004, Bulletin of the Seismological Society of America (94) 1571-1578
According to some compilations, the Laguna Salada, Baja California, earthquake of 23 February 1892 ranks among the largest earthquakes in California and Baja California in historic times. Although surface rupture was not documented at the time of the earthquake, recent geologic investigations have identified and mapped a rupture on the...
A unique approach to estimating lateral anisotropy in complex geohydrologic environments
K. J. Halford, B. Campbell
2004, Journal of Hydraulic Research (42) 77-81
Aquifers in fractured rock or karstic settings are likely to have anisotropic transmissivity distributions. Aquifer tests that are performed in these settings also are frequently affected by leakage from adjacent confining units. Finite-difference models such as MODFLOW are convenient tools for estimating the hydraulic characteristics of the stressed aquifer and...
Late Quaternary stratigraphy and geochronology of the western Killpecker Dunes, Wyoming, USA
J. H. Mayer, S. A. Mahan
2004, Quaternary Research (61) 72-84
New stratigraphic and geochronologic data from the Killpecker Dunes in southwestern Wyoming facilitate a more precise understanding of the dune field's history. Prior investigations suggested that evidence for late Pleistocene eolian activity in the dune field was lacking. However, luminescence ages from eolian sand of ???15,000 yr, as well as...
A Complex Systems Model Approach to Quantified Mineral Resource Appraisal
M. E. Gettings, M.W. Bultman, F. S. Fisher
2004, Environmental Management (33) 87-98
For federal and state land management agencies, mineral resource appraisal has evolved from value-based to outcome-based procedures wherein the consequences of resource development are compared with those of other management options. Complex systems modeling is proposed as a general framework in which to build models that can evaluate outcomes. Three...
Characterization and origin of polar dissolved organic matter from the Great Salt Lake
J.A. Leenheer, T.I. Noyes, C.E. Rostad, M.L. Davisson
2004, Biogeochemistry (69) 125-141
Polar dissolved organic matter (DOM) was isolated from a surface-water sample from the Great Salt Lake by separating it from colloidal organic matter by membrane dialysis, from less-polar DOM fractions by resin sorbents, and from inorganic salts by a combination of sodium cation exchange followed by precipitation of sodium salts...
Active shortening of the Cascadia forearc and implications for seismic hazards of the Puget Lowland
S. Y. Johnson, R.J. Blakely, W. J. Stephenson, S. V. Dadisman, M. A. Fisher
2004, Tectonics (23)
Margin-parallel shortening of the Cascadia forearc is a consequence of oblique subduction of the Juan de Fuca plate beneath North America. Strike-slip, thrust, and oblique crustal faults beneath the densely populated Puget Lowland accommodate much of this north-south compression, resulting in large crustal earthquakes. To better understand this forearc deformation...
Stratovolcano stability assessment methods and results from Citlaltepetl, Mexico
D. R. Zimbelman, R.J. Watters, I.R. Firth, G. N. Breit, Gerardo Carrasco-Nunez
2004, Bulletin of Volcanology (66) 66-79
Citlaltépetl volcano is the easternmost stratovolcano in the Trans-Mexican Volcanic Belt. Situated within 110 km of Veracruz, it has experienced two major collapse events and, subsequent to its last collapse, rebuilt a massive, symmetrical summit cone. To enhance hazard mitigation efforts we assess the stability of Citlaltépetl's summit cone, the area...
The Hurricane-flood-landslide continuum-forecasting Hurricane effects at landfall
A. J. Negri, J. H. Golden, R. G. Updike
2004, Conference Paper, Bulletin of the American Meteorological Society
The integration of remote-sensing and in-situ observations, and assimilation of these observations into high-resolution mesoscale models was described. It was observed that the greatest loss of life and property is the direct result of the storm because of the high winds and heavy rain. The research were conducted to develop...
Water table fluctuations near an incised stream, Walnut Creek, Iowa
K. E. Schilling, Y.-K. Zhang, P. Drobney
2004, Journal of Hydrology (286) 236-248
Incised channels are common features in many agricultural watersheds, but the effects of channel incision on riparian water table conditions have been poorly documented. In this study, we evaluate the water table fluctuations in the floodplain near an incised stream (Walnut Creek, Iowa) and investigate the roles that channel incision...
Carnivore re-colonisation: Reality, possibility and a non-equilibrium century for grizzly bears in the southern Yellowstone ecosystem
Sanjay Pyare, S. Cain, D. Moody, C. Schwartz, J. Berger
2004, Animal Conservation (7) 71-77
Most large native carnivores have experienced range contractions due to conflicts with humans, although neither rates of spatial collapse nor expansion have been well characterised. In North America, the grizzly bear (Ursus arctos) once ranged from Mexico northward to Alaska, however its range in the continental USA has been reduced...
Fast ground-water mixing and basal recharge in an unconfined, alluvial aquifer, Konza LTER Site, Northeastern Kansas
G.L. Macpherson, M. Sophocleous
2004, Journal of Hydrology (286) 271-299
Ground-water chemistry and water levels at three levels in a well nest were monitored biweekly for two and a half years in a shallow unconfined floodplain aquifer in order to study the dynamics of such shallow aquifers. The aquifer, in northeastern Kansas, consists of high porosity, low hydraulic conductivity fine-grained...
Methods for estimating adsorbed uranium(VI) and distribution coefficients of contaminated sediments
M. Kohler, G.P. Curtis, D.E. Meece, J.A. Davis
2004, Environmental Science & Technology (38) 240-247
Assessing the quantity of U(VI) that participates in sorption/desorption processes in a contaminated aquifer is an important task when investigating U migration behavior. U-contaminated aquifer sediments were obtained from 16 different locations at a former U mill tailings site at Naturita, CO (U.S.A.) and were extracted with an artificial groundwater,...
