The Spirit Rover's Athena science investigation at Gusev crater, Mars
S. W. Squyres, R. E. Arvidson, J.F. Bell III, J. Bruckner, N.A. Cabrol, W. Calvin, M. H. Carr, P. R. Christensen, B. C. Clark, L. Crumpler, D.J. Des Marais, C. D'Uston, T. Economou, J. Farmer, W. Farrand, W. Folkner, M. Golombek, S. Gorevan, J. A. Grant, R. Greeley, J. Grotzinger, L. Haskin, Kenneth E. Herkenhoff, S. Hviid, J. Johnson, G. Klingelhofer, A. Knoll, G. Landis, M. Lemmon, R. Li, M.B. Madsen, M. C. Malin, S. M. McLennan, H.Y. McSween, D. W. Ming, J. Moersch, R.V. Morris, T. Parker, J. W. Rice Jr., L. Richter, R. Rieder, M. Sims, M. Smith, P. Smith, Laurence A. Soderblom, R. Sullivan, H. Wanke, T. Wdowiak, M. Wolff, A. Yen
2004, Science (305) 794-799
The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. Gusev is hypothesized to be the site of a former take, but no clear evidence for lacustrine sedimentation has been found to date. Instead, the dominant lithology is basalt,...
Isotopic evidence bearing on Late Triassic extinction events, Queen Charlotte Islands, British Columbia, and implications for the duration and cause of the Triassic/Jurassic mass extinction
P.D. Ward, G.H. Garrison, J.W. Haggart, D.A. Kring, M.J. Beattie
2004, Earth and Planetary Science Letters (224) 589-600
Stable isotope analyses of Late Triassic to earliest Jurassic strata from Kennecott Point in the Queen Charlotte Islands, British Columbia, Canada shows the presence of two distinct and different organic carbon isotope anomalies at the Norian/Rhaetian and Rhaetian/Hettangian (=Triassic/Jurassic) stage boundaries. At the older of these boundaries, which is marked...
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,...
Development of an AMS method to study oceanic circulation characteristics using cosmogenic 39Ar
P.H. Collon, M. Bichler, J. Caggiano, L.D. Cecil, Masri Y. El, R. Golser, C.L. Jiang, A. Heinz, D. Henderson, W. Kutschera, B.E. Lehmann, P. Leleux, H.H. Loosli, R.C. Pardo, M. Paul, K.E. Rehm, P. Schlosser, R.H. Scott, W.M. Smethie Jr., R. Vondrasek
2004, Conference Paper, Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Initial experiments at the ATLAS facility [Nucl. Instr. and Meth. B 92 (1994) 241] resulted in a clear detection of cosmogenic 39Ar signal at the natural level. The present paper summarizes the recent developments of 39Ar AMS measurements at ATLAS: the use of an electron cyclotron resonance (ECR) positive ion...
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...
Formation of a paleothermal anomaly and disseminated gold deposits associated with the Bingham Canyon porphyry Cu-Au-Mo system, Utah
C. G. Cunningham, G.W. Austin, C. W. Naeser, R. O. Rye, G.H. Ballantyne, R.G. Stamm, C.E. Barker
2004, Economic Geology (99) 789-806
The thermal history of the Oquirrh Mountains, Utah, indicates that hydrothermal fluids associated with emplacement of the 37 Ma Bingham Canyon porphyry Cu-Au-Mo deposit extended at least 10 km north of the Bingham pit. An associated paleothermal anomaly enclosed the Barneys Canyon and Melco disseminated gold deposits and several smaller...
Formation of jets in Comet 19P/Borrelly by subsurface geysers
R.V. Yelle, L.A. Soderblom, J.R. Jokipii
2004, Icarus (167) 30-36
Observations of the inner coma of Comet 19P/Borrelly with the camera on the Deep Space 1 spacecraft revealed several highly collimated dust jets emanating from the nucleus. The observed jets can be produced by acceleration of evolved gas from a subsurface cavity through a narrow orifice to the surface. As...
Glacial-interglacial organic carbon record from the Makassar Strait, Indonesia: Implications for regional changes in continental vegetation
K. Visser, R. Thunell, M.A. Goni
2004, Quaternary Science Reviews (23) 17-27
Recent studies convincingly show that climate in the Western Pacific Warm Pool and other equatorial/tropical regions was significantly colder (by ???3-4??C) during glacial periods, prompting a reexamination of the late Pleistocene paleoenvironments of these regions. This study examines changes in continental vegetation during the last two deglaciations (Terminations I and...
Combination of LC/TOF-MS and LC/Ion Trap MS/MS for the Identification of Diphenhydramine in Sediment Samples
I. Ferrer, C.E. Heine, E.M. Thurman
2004, Analytical Chemistry (76) 1437-1444
Diphenhydramine (Benadryl) is a popular over-the-counter antihistaminic medication used for the treatment of allergies. After consumption, excretion, and subsequent discharge from wastewater treatment plants, it is possible that diphenhydramine will be found in environmental sediments due to its hydrophobicity (log P = 3.27). This work describes a methodology for the...
Influence of near-surface stratigraphy on coastal landslides at Sleeping Bear Dunes National Lakeshore, Lake Michigan, USA
W. A. Barnhardt, B. E. Jaffe, R. E. Kayen, G.R. Cochrane
2004, Journal of Coastal Research (20) 510-522
Lake-level change and landslides are primary controls on the development of coastal environments along the coast of northeastern Lake Michigan. The late Quaternary geology of Sleeping Bear Dunes National Lakeshore was examined with high-resolution seismic reflection profiles, ground-penetrating radar (GPR), and boreholes. Based on sequence-stratigraphic principles, this study recognizes ten...
Geographic structure of adelie penguin populations: overlap in colony-specific foraging areas
D. G. Ainley, C. A. Ribic, G. Ballard, S. Heath, I. Gaffney, B. J. Karl, K. J. Barton, P. R. Wilson, S. Webb
2004, Ecological Monographs (74) 159-178
In an investigation of the factors leading to geographic structuring among Ade??lie Penguin (Pygoscelis adeliae) populations, we studied the size and overlap of colony-specific foraging areas within an isolated cluster of colonies. The study area, in the southwestern Ross Sea, included one large and three smaller colonies, ranging in size...
EXAFS study of mercury(II) sorption to Fe- and Al-(hydr)oxides: I. Effects of pH
C.S. Kim, J. J. Rytuba, Gordon E. Brown Jr.
2004, Journal of Colloid and Interface Science (271) 1-15
The study of mercury sorption products in model systems using appropriate in situ molecular-scale probes can provide detailed information on the modes of sorption at mineral/water interfaces. Such studies are essential for assessing the influence of sorption processes on the transport of Hg in contaminated natural systems. Macroscopic uptake of...
Rhyodacites of Kulshan caldera, North Cascades of Washington: Postcaldera lavas that span the Jaramillo
W. Hildreth, M. A. Lanphere, D.E. Champion, J. Fierstein
2004, Journal of Volcanology and Geothermal Research (130) 227-264
Kulshan caldera (4.5×8 km), at the northeast foot of Mount Baker, is filled with rhyodacite ignimbrite (1.15 Ma) and postcaldera lavas and is only the third Quaternary caldera identified in the Cascade arc. A gravity traverse across the caldera yields a steep-sided, symmetrical, complete Bouguer anomaly of −16 mGal centered...
Identification of spectrally similar materials using the USGS Tetracorder algorithm: The calcite-epidote-chlorite problem
J.B. Dalton, D. J. Bove, C.S. Mladinich, B.W. Rockwell
2004, Remote Sensing of Environment (89) 455-466
A scheme to discriminate and identify materials having overlapping spectral absorption features has been developed and tested based on the U.S. Geological Survey (USGS) Tetracorder system. The scheme has been applied to remotely sensed imaging spectroscopy data acquired by the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS) instrument. This approach...
Sources of osmium to the modern oceans: New evidence from the 190Pt-186Os system
D.K. McDaniel, R.J. Walker, S. R. Hemming, M.F. Horan, H. Becker, R. I. Grauch
2004, Geochimica et Cosmochimica Acta (68) 1243-1252
High precision Os isotope analysis of young marine manganese nodules indicate that whereas the composition of modern seawater is radiogenic with respect to 187Os/188Os, it has 186Os/188Os that is within uncertainty of the chondritic value. Marine Mn nodule compositions thus indicate that the average continental source of Os to modern...
Occurrence of riverine wetlands on floodplains along a climatic gradient
D.E. Kroes, M.M. Brinson
2004, Wetlands (24) 167-177
The relation between the occurrence of riverine wetlands in floodplains along a humid to semi-arid climatic continuum was studied in two regions. The first included 36 mid-reach streams from Colorado to Iowa, USA, a region with a broad range of PET ratios (potential evapotranspiration/precipitation) from 0.70 to 1.75. The second...
Quarry expansion - Sustainable management of natural aggregate
W. H. Langer, M. L. Tucker
2004, Mining Engineering (56) 23-28
[No abstract available]...
Geochemical models of metasomatism in ultramafic systems: Serpentinization, rodingitization, and sea floor carbonate chimney precipitation
J.L. Palandri, M.H. Reed
2004, Geochimica et Cosmochimica Acta (68) 1115-1133
In a series of water-rock reaction simulations, we assess the processes of serpentinization of harzburgite and related calcium metasomatism resulting in rodingite-type alteration, and seafloor carbonate chimney precipitation. At temperatures from 25 to 300??C (P = 10 to 100 bar), using either fresh water or seawater, serpentinization simulations produce an...
An evaluation of multipass electrofishing for estimating the abundance of stream-dwelling salmonids
J.T. Peterson, R.F. Thurow, J.W. Guzevich
2004, Transactions of the American Fisheries Society (133) 462-475
Failure to estimate capture efficiency, defined as the probability of capturing individual fish, can introduce a systematic error or bias into estimates of fish abundance. We evaluated the efficacy of multipass electrofishing removal methods for estimating fish abundance by comparing estimates of capture efficiency from multipass removal estimates to capture...
Temporal scaling of hydraulic head and river base flow and its implication for groundwater recharge
You-Kuan Zhang, Keith Schilling
2004, Water Resources Research (40)
Spectral analyses were conducted for hourly hydraulic head (h) data observed over a 4‐year period at seven monitoring wells in the Walnut Creek watershed, Iowa. The log power spectral density of the hydraulic head fluctuations versus log frequency (f) at all seven wells is shown to have a distinct slope...
EXAFS study of mercury(II) sorption to Fe- and Al-(hydr)oxides - II. Effects of chloride and sulfate
C.S. Kim, J. J. Rytuba, Gordon E. Brown Jr.
2004, Journal of Colloid and Interface Science (270) 9-20
Common complexing ligands such as chloride and sulfate can significantly impact the sorption of Hg(II) to particle surfaces in aqueous environmental systems. To examine the effects of these ligands on Hg(II) sorption to mineral sorbents, macroscopic Hg(II) uptake measurements were conducted at pH 6 and [Hg]i=0.5 mM on goethite (??-FeOOH),...
Introduction to genetics of subpolar fish and invertebrates
A.J. Gharrett, S. Keller, R.G. Gustafson, P. Johnson, J.L. Nielsen, J.E. Seeb, Lisa W. Seeb, W.W. Smoker, G.H. Thorgaard, R.L. Wilmot
2004, Conference Paper, Environmental Biology of Fishes
[No abstract available]...
Assessing the record and causes of Late Triassic extinctions
L.H. Tanner, S. G. Lucas, M. G. Chapman
2004, Earth-Science Reviews (65) 103-139
Accelerated biotic turnover during the Late Triassic has led to the perception of an end-Triassic mass extinction event, now regarded as one of the "big five" extinctions. Close examination of the fossil record reveals that many groups thought to be affected severely by this event, such as ammonoids, bivalves and...
Drowning of the - 150 m reef off Hawaii: A casualty of global meltwater pulse 1A?
J.M. Webster, D.A. Clague, K. Riker-Coleman, C. Gallup, J.C. Braga, D. Potts, J.G. Moore, E.L. Winterer, C. K. Paull
2004, Geology (32) 249-252
We present evidence that the drowning of the - 150 m coral reef around Hawaii was caused by rapid sea-level rise associated with meltwater pulse 1A (MWP-1A) during the last deglaciation. New U/Th and 14C accelerator mass spectrometry dates, combined with reinterpretation of existing radiometric dates, constrain the age of...
A comparison of genetic ariation between an anadromous steelhead, Oncorhynchus mykiss, population and seven derived populations sequestered in freshwater for 70 years
Frank Thrower, Charles Guthrie III, Jennifer L. Nielsen, John Joyce
2004, Environmental Biology of Fishes (69) 111-125
In 1926 cannery workers from the Wakefield Fisheries Plant at Little Port Walter in Southeast Alaska captured small trout, Oncorhynchus mykiss, from a portion of Sashin Creek populated with a wild steelhead (anadromous O. mykiss) run. They planted them into Sashin Lake which had been fishless...
