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The alluvial aquifer in Fountain Creek Valley between Colorado Springs and Widefield is the source for several public water-supply systems. Since 1981, concentrations of dissolved nitrite plus nitrate as nitrogen (nitrate) have exceeded the drinking-water standard of 10 milligrams per liter in several areas of the aquifer. Water-quality data collected...

This Compact Disc-Read Only Memory (CD-ROM) contains a program illustrating the geology and mineral and energy resources of the Roswell Resource Area, an administrative unit of the U.S. Bureau of Land Management in east-central New Mexico. The program enables the user to access information on the geology, geochemistry, geophysics, mining...

No abstract available....

Synthetic schwertmannite samples with varying amounts of arsenate and selenate substituting for sulfate were examined by XAS methods in an attempt to characterize the location of the anion complexes. Selenate appears to both substitute directly for sulfate within tunnels in the structure, and sorb onto the outside of crystallites. No...

Firm stratigraphic correlations are needed to evaluate the global significance of unconformity bounded units (sequences). We correlate the well-developed uppermost Campanian and Maestrichtian sequences of the New Jersey Coastal Plain to the geomagnetic polarity time scale (GPTS) by integrating Sr-isotopic stratigraphy and biostratigraphy. To do this, we developed a Maestrichtian...

Since the turn of the century the well-developed Kenya rift has been a crucial location for studying the interrelationships between extension, uplift, and magmatism. In 1989–1990, an experiment conducted by the Kenya Rift International Seismic Project (KRISP) focused on the central and northern portions of Kenya (Figure 1) and provided...

Shear-wave splitting from local microearth-quakes recorded in The Geysers geothermal field shows that seismic anisotropy is distributed in a complex geographic pattern. At stations within about 2 km of northwest-striking regional faults, the fast polarization direction is parallel to those faults. The geothermal field, lying between two such faults, has...

Although the shorelines of Prince William Sound still bear traces of the 1989 Exxon Valdez oil spill, most of the flattened tar balls that can be found today on these shorelines are not residues of Exxon Valdez oil. Instead, the carbon-isotopic and hydrocarbonbiomarker signatures of 61 tar ball samples, collected...

A permanent Global Positioning System receiver at Casa Diablo Hot Springs, Long Valley Caldera, California was installed in January, 1993, and has operated almost continuously since then. The data have been transmitted daily to the Jet Propulsion Laboratory for routine analysis with data from the Fiducial Laboratories for an International...

No abstract available....

Comparison of ((234U)excess(238U)">234U) excess⁄(238U) and ((230Th232Th">230Th⁄232Th) activity ratios in oceanic Fe-Mn deposits provides a method for assessing the closed-system behaviour of 238U-234U-230Th, as well as variations in the initial uranium and thorium isotopic ratios of the precipitated metal oxides. This...

The geological evolution of the northern Peru convergent margin can be traced using samples collected during deep-sea dives of the submersible Nautile. In the Paita area (5°–6°S), the sedimentary sequence was intensively sampled along the main scarp of the middle slope area. It consists of Upper Miocene (7–9 Ma) to Pleistocene...

Detailed stratigraphy and isotopic dating of stratigraphic sections in the Colorado River extensional corridor support a regional correlation of highly faulted Tertiary stratigraphic sequences and provide a chronologic framework for interpreting the evolution of low-angle normal (detachment) faults. On the basis of this correlation, we define six tilting domains in...

The purpose of the National Oil and Gas Resource Assessment Project is to develop a set of scientifically based hypotheses concerning the quantities of oil and gas that could be added to the measured (proved) reserves of the United States. The word assessment sometimes has the connotation...

Laboratory experiments were used to identify and quantify processes having a significant effect on molybdate (MoO42−) adsorption in a shallow alluvial aquifer on Cape Cod, assachusetts. Aqueous chemistry in the aquifer changes as a result of treated sewage effluent mixing with groundwater. Molybdate adsorption decreased as pH, ionic strength, and the...

The distribution of microbially mediated terminal electron-accepting processes (TEAPs( was investigated in four hydrologically diverse groundwater systems by considering patterns of electron acceptor (nitrate, sulfate) consumption, intermediate product (hydrogen (H2)) concentrations, and final product (ferrous iron, sulfide, and methane) production. In each hydrologic system a determination of predominant TEAPs could...

Simulation of induced movement of air in the unsaturated zone provides a method to determine permeability and to design vapor extraction remediation systems. A previously published solution to the airflow equation for the case in which the unsaturated zone is separated from the atmosphere by a layer of lower permeability...

The occurrence of swollen or hyperostotic bones in skeletal preparations, preserved museum material or whole fresh specimens of marine teleost fishes was identified in 92 species belonging to 22 families. Patterns of hyperostotic skeletal growth were typically consistent and often species-specific in all individuals larger than a certain size. The...

This volume contains 67 extended abstracts that summarize some of the oral and poster presentations of the tenth annual V. E. McKelvey forum on mineral and energy resources, held in Washington, D.C., Feb. 13-17, 1995. The focus is on our energy resources and the environment, new research techniques, and cooperative...

No abstract available....

Similar successions of planktonic foraminifera, calcareous nannofossils, and bolboformids document coeval deposition of the Exmore impact breccia (Virginia Coastal Plain) and an impact ejecta layer at DSDP Site 612 (New Jersey Continental Slope). Both impactites accumulated in the late Eocene during the early part of biochrons P15 (planktonic foraminifera) and...

Sorption of thorium by pre-existing crystals of anglesite (PbSO4), apatite (Ca5(PO4)3(HO)), barite (BaSO4), bentonite (Na0.7Al3.3Mg0.7Si8O20(OH)4), celestite (SrSO4), fluorite (CaF2), galena (PbS), gypsum (CaSO4·2H2O), hematite (Fe2O3), jarosite (KFe3(SO4)2(OH)6), kaolinite (Al2O3·2SiO2·2H2O), quartz (SiO2) and sodium feldspar (NaAlSi3O8) was studied under conditions that simulate an acidic uranium mill effluent environment. Up to 100%...