Hydrogeologic Aspects of the International Hydrological Decade     

W. C. Walton Member NWWA 《Ground water》1966,4(4):36-47

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Holocene Climate in the Northern Great Plains Inferred from Sediment Stratigraphy, Stable Isotopes, Carbonate Geochemistry, Diatoms, and Pollen at Moon Lake, North Dakota     

Blas L. Valero-Garcés  Kathleen R. Laird  Sherilyn C. Fritz  Kerry Kelts  Emi Ito  Eric C. Grimm 《Quaternary Research》1997,48(3):359-369

Seismic stratigraphy, sedimentary facies, pollen stratigraphy, diatom-inferred salinity, stable isotope (δ¹⁸O and δ¹³C), and chemical composition (Sr/Ca and Mg/Ca) of authigenic carbonates from Moon Lake cores provide a congruent Holocene record of effective moisture for the eastern Northern Great Plains. Between 11,700 and 9500¹⁴C yr B.P., the climate was cool and moist. A gradual decrease in effective moisture occurred between 9500 and 7100¹⁴C yr B.P. A change at about 7100¹⁴C yr B.P. inaugurated the most arid period during the Holocene. Between 7100 and 4000¹⁴C yr B.P., three arid phases occurred at 6600–6200¹⁴C yr B.P., 5400–5200¹⁴C yr B.P., and 4800–4600¹⁴C yr B.P. Effective moisture generally increased after 4000¹⁴C yr B.P., but periods of low effective moisture occurred between 2900–2800¹⁴C yr B.P. and 1200–800¹⁴C yr B.P. The data also suggest high climatic variability during the last few centuries. Despite the overall congruence, the biological (diatom), sedimentological, isotopic, and chemical proxies were occassionally out of phase. At these times the evaporative process was not the only control of lake-water chemical and isotopic composition.  相似文献   

The effects of a gas well blow out on groundwater chemistry     

Walton Ross Kelly  Gerald Matisoff  J. Berton Fisher 《Environmental Geology》1985,7(4):205-213

Water wells were sampled near North Madison, Ohio, following a gas well blow out that injected large amounts of CH₄ into near-surface groundwater Chemical analyses showed elevated levels of Fe⁺², Mn⁺², Ca⁺², sulfide, alkalinity, and pH, and low levels of dissolved oxygen, SO₄ ⁻², and NO₃ ⁻ in CH₄-affected wells compared to unaffected wells. Sulfate reduction is quantitatively the most important vehicle for CH₄ oxidation Equilibrium thermodynamic computer models were used to simulate groundwaters from the North Madison area Model results showed that CH₄ is oxidized to HCO₃ ⁻, SO₄ ⁻² is reduced, iron and manganese oxides are reduced and dissolved, and pH increases These simulations are in excellent agreement with trends observed in the field data A laboratory experiment was designed to simulate CH₄ ⁻ perturbed groundwater in the methane-perturbed system, sulfide increased significantly, providing direct evidence for methane oxidation by sulfate reduction Although suitable anaerobic methane-oxidizing bacteria have not been isolated from groundwater aquifers, the combination of field data, laboratory experiment, and computer simulation form a convincing argument that CH₄ perturbation of aquifers can and does affect groundwater chemistry  相似文献   

Pollution control and recession     

Timothy O&#x;Riordan  R.Kerry Turner 《Marine pollution bulletin》1984,15(1):5-11

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Bayesian Mixture Modelling in Geochronology via Markov Chain Monte Carlo     

Ajay Jasra  David A. Stephens  Kerry Gallagher  Christopher C. Holmes 《Mathematical Geology》2006,38(3):269-300

In this paper we develop a generalized statistical methodology for characterizing geochronological data, represented by a distribution of single mineral ages. The main characteristics of such data are the heterogeneity and error associated with its collection. The former property means that mixture models are often appropriate for their analysis, in order to identify discrete age components in the overall distribution. We demonstrate that current methods (e.g., Sambridge and Compston, 1994) for analyzing such problems are not always suitable due to the restriction of the class of component densities that may be fitted to the data. This is of importance, when modelling geochronological data, as it is often the case that skewed and heavy tailed distributions will fit the data well. We concentrate on developing (Bayesian) mixture models with flexibility in the class of component densities, using Markov chain Monte Carlo (MCMC) methods to fit the models. Our method allows us to use any component density to fit the data, as well as returning a probability distribution for the number of components. Furthermore, rather than dealing with the observed ages, as in previous approaches, we make the inferences of components from the “true” ages, i.e., the ages had we been able to observe them without measurement error. We demonstrate our approach on two data sets: uranium-lead (U-Pb) zircon ages from the Khorat basin of northern Thailand and the Carrickalinga Head formation of southern Australia.  相似文献   

Lessons learned in remediation and restoration in the Oklahoma prairie: A review     

Kerry L. Sublette  J. Bryan Tapp  J. Berton Fisher  Eleanor Jennings  Kathleen Duncan  Greg Thoma  Josh Brokaw  Tim Todd 《Applied Geochemistry》2007

For almost a decade the Tallgrass Prairie Preserve in Oklahoma has been used as a field laboratory for the investigation of aspects of the remediation and restoration of oil and brine spills. Objectives of this work have included: (1) simplification of the remediation process and lowering the cost of remediation; (2) the development of methods to accelerate or jump-start the restoration process; and (3) determining appropriate metrics for assessing the status of soil ecosystem recovery. This research has resulted in a number of lessons learned that will be presented here which can be exported to other exploration and production sites, especially sites located in sensitive ecosystems. Key observations have included the role of a fertilizer amendment in linking the remediation and restoration process at an oil-impacted site, the use of nematodes as ecological indicators in the restoration of oil- and brine-impacted sites, and the development of a two-stage process for remediation of brine impacted sites that does not include significant use of gypsum.  相似文献   

Quantifying contributions to stream salinity using electromagnetic induction and hydrochemistry in a small Texas coastal-plain basin     

Jeffrey G. Paine  H.S. Nance  Edward W. Collins  Kerry L. Niemann 《Applied Geochemistry》2007

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Effect of plant growth on Pb and Zn geoaccumulation in 300-year-old mine tailings of Zacatecas,México     

Juan Armando Flores de la Torre  Kerry Mitchell  Magdalena Samantha Ramos Gómez  Alma Lilian Guerrero Barrera  Laura Yamamoto Flores  Francisco Javier Avelar González 《Environmental Earth Sciences》2018,77(10):386

Concentrations of Pb and Zn, plant uptake of these metals, the influence of the plants’ growth on the physicochemical properties and metal concentrations in the tailings of an abandoned 300-year-old mine tailing dam in Zacatecas, Mexico were investigated. Tailings were found to be heavily contaminated, with average levels of 2621 ± 53 and 3827 ± 83 mg/kg for Pb and Zn, respectively (maximum concentrations of 8466 ± 116 and 12,475 ± 324 mg/kg, respectively), exceeding international standards. Though physico-chemical conditions (pH, conductivity, redox potential, moisture, organic matter, nitrate, nitrite, ammonium nitrogen, total nitrogen, phosphorus and sulfates) do not favor the development of vegetation, some plants have adapted to these adverse conditions. Moreover, there was a significant reduction of Pb and Zn concentration in the rhizosphere (between 10–78% for Pb and 18–62% for Zn, depending on plant species). Sporobolus airoides showed average biomass concentrations of 173 ± 2 and 313 ± 6 mg/kg, for Pb and Zn, respectively; which implies a risk for mobility and possible incorporation into the food chain. Barcleyanthus salicifolius, Asclepsias linaria and Cortaderia selloana on the other hand, showed average biomass concentrations of 28 ± 3 and 121 ± 5 mg/kg of Pb and Zn, respectively, thus representing a lower biomagnification risk. The effect of these plants to reduce metal concentrations in the rhizosphere, improve physico-chemical conditions in metal polluted substrates, but with limited metal accumulation in biomass, suggests that they can be evaluated for use in stabilizing metal polluted tailings.  相似文献   

Joint effects of storm surge and sea-level rise on US Coasts: new economic estimates of impacts,adaptation, and benefits of mitigation policy     

James E. Neumann  Kerry Emanuel  Sai Ravela  Lindsay Ludwig  Paul Kirshen  Kirk Bosma  Jeremy Martinich 《Climatic change》2015,129(1-2):337-349

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Sensitivity Testing of the Newly Developed Elliptical Fitting Method for the Measurement of Convergence in Tunnels and Shafts   总被引：1，自引：1，他引：0  

Danielle Delaloye  Mark S. Diederichs  Gabriel Walton  Jean Hutchinson 《Rock Mechanics and Rock Engineering》2015,48(2):651-667

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