Despite a richly-documented history of metallurgy following Hispanic conquest of the Inca, little is known concerning the loci and intensities of earlier metallurgical activities. Lake sediments offer one strategy to reconstruct this history because the deposition of trace elements associated with smelting form a continuous archive that can be assessed in the context of regional archaeology. To reconstruct regional histories of late Holocene atmospheric pollution, two lake sediment cores were collected from mining areas in the central Peruvian Andes. Lake sediment stratigraphies of elemental concentrations and isotopic ratios preserve a regional record of pre-Incan, Incan, and Colonial smelting practices. Our records provide the first evidence for intensive, pre-Colonial smelting in the central Peruvian Andes, and corroborate earlier findings from Bolivia. Surprisingly, smelting appears to have operated independent of oversight from the Wari (500 to 1000 AD) or Inca (1460 to 1532 AD) Empires. With Spanish arrival, smelting activity increased dramatically, only to be superseded by post-industrial pollution. The two central Andean records were compared to two Bolivian records of atmospheric pollution. Initial Pb enrichment in Bolivia occurs contemporaneously with records from Peru ca. 400 AD. In Bolivia, this coincides with the expansion of the Tiwanaku Empire (ca. 400 to 1000 AD). Inca expansion across both Peru and Bolivia (~1450 AD) led to increased metallurgical activity at all four study sites. Our findings demonstrate the usefulness of paleolimnological methods for reconstructing the timing and magnitude of smelting activity throughout the New World, and thus contribute directly to a fragmentary archaeological record.

Production of methane from thick, extensive coalbeds in the Powder River Basin of Wyoming has created water management issues. More than 4.1 billion barrels of water have been produced with coalbed natural gas (CBNG) since 1997. Infiltration impoundments, which are the principal method used to dispose CBNG water, contribute to the recharge of underlying aquifers. Airborne electromagnetic surveys of an alluvial aquifer that has been receiving CBNG water effluent through infiltration impoundments since 2001 reveal produced water plumes within these aquifers and also provide insight into geomorphologic controls on resultant salinity levels. Geochemical data from the same aquifer reveal that CBNG water enriched in sodium and bicarbonate infiltrates and mixes with sodium-calcium-sulfate type alluvial groundwater, which subsequently may have migrated into the Powder River. The highly sodic produced water undergoes cation exchange reactions with native alluvial sediments as it infiltrates, exchanging sodium from solution for calcium and magnesium on montmorillonite clays. The reaction may ultimately reduce sediment permeability by clay dispersion. Strontium isotope data from CBNG wells discharging water into these impoundments indicate that the Anderson coalbed of the Fort Union Formation is dewatered due to production. Geophysical methods provide a broad-scale tool to monitor CBNG water disposal especially in areas where field based investigations are logistically prohibitive, but geochemical data are needed to reveal subsurface processes undetectable by geophysical techniques. The results of this research show that: (1) CBNG impoundments should not be located near streams because they can alter the surrounding hydraulic potential field forcing saline alluvial groundwater and eventually CBNG water into the stream, (2) point bars are poor impoundment locations because they are essentially in direct hydraulic communication with the associated stream and because plants readily transpire shallow groundwater within them creating vadose zone salt accumulations that will be dissolved by infiltrating CBNG water, and (3) cation exchange reactions in vadose zone sediments may reduce soil permeability beneath infiltration impoundments through clay dispersion lowering their designed disposal capacity.

Concern for environmental degradation in response to recent warming trends is highly relevant for modern Mongolian society. A general lack of high-resolution, long-term information on regional environmental history however, limits any thorough understanding of the potential rate and extent of such ecosystem alteration. Paleoenvironmental methods are thereby required to assess baseline conditions within sensitive ecosystems and thereby evaluate past climate and environmental changes. Here, a detailed paleolimnological study of northern Mongolian lakes is presented in an effort to examine the response of sensitive lake systems to climatic variation during the Holocene. More specifically, eight high-alpine lakes with the Baroon Taiga Mountains of northern Mongolia were identified and studied as part of a broad survey of north/central Mongolian lake systems. The application of diffuse reflectance spectroscopy and standard loss-on-ignition techniques to radiocarbon-dated sediment core samples provides a high-resolution history of late Holocene algal productivity within the basins of Sanjin, Asgat and Ganbold Nuur, and a low-resolution full-Holocene paleoproductivity history for Mustei Nuur. Evidence for a long-term decrease in production rates in response to orbital forcing from 8000 cal yr B.P. is provided by the Mustei Nuur record. Inter-core comparison of high-resolution records provides evidence for regional growing season temperature variations as the dominant mechanism controlling higher frequency aquatic productivity variations during the late Holocene period. Diminished regional aquatic productivity trends are observed during the Little Ice Age (300 100 cal yr B.P.). Increased productivity is noted between 900 and 1100 cal yr B.P. (coincident with the so-called Medieval Climatic Anomaly) and from ~ 100 cal yr B.P. to the present, likely in response to 20th century warming trends. A direct comparison of the Sanjin and Ganbold Nuur aquatic productivity records to nearby tree-ring based temperature reconstructions supports the hypothesis that the high-frequency aquatic productivity changes reflect regional temperature variations, and thereby extend the regional temperature reconstructions to 3000 cal yr B.P.

Southern Nevada is geologically and structurally complex. Detailed geologic mapping is critical to the understanding of the geologic history and groundwater flow within the region. The Las Vegas Valley shear zone (LVVSZ) is a strike-slips fault along which approximately 50 km of right-lateral movement took place between about 15-10 Ma. The shear zone extends northwestward about 100 km from Las Vegas to Mercury, Nevada. Folded Miocene strata record contraction west of Mercury where the LVVSZ is inferred to bend westward beneath the southern Specter Range creating a positive flower structure in response to transpression. Geologic mapping southwest of Mercury shows that Neoproterozoic and Early Paleozoic carbonate and clastic strata comprise a thick section of rocks deformed by multiple gently dipping faults along which units are detached. The footwalls and hanging walls adjacent to the fault surfaces are generally marked by pebbly cataclastic breccia or less commonly by foliation in fine-grained rocks. The detachments, which commonly crop out in the northernmost Spring Mountains, dip gently north toward the Specter Range. Rare kinematic indicators record south-directed transport. A principal hanging wall of the fault zone is composed of brecciated Late Cambrian Nopah Formation. Detachment breccias show significant secondary porosity and permeability, which may control groundwater flow between the Spotted Range and Specter Range. Adjacent to the detachment about 1.4 to 3 kilometers of strata are missing between Nopah beds and fault slices of much lower Early Cambrian Wood Canyon Formation. The footwall of the Nopah detachment comprises two parts: 1) Neoproterozoic and Cambrian strata folded about north-trending hinges and 2) an adjacent basin. Brecciated Nopah Formation and underlying fault rocks rest upon the folded strata of the footwall, and breccia also crops out in an adjacent former lake where they are recorded by crudely tabular masses of breccia intercalated with bodies of carbonate-clast conglomerate. The detachment fault zone is a contractional feature that is compatible with transpression expected along the left-step restraining bend in the LVVSZ.

Coal combustion for energy generation creates large quantities of solid coal utilization by-products (CUB), including fly ash, bottom ash, and flue gas desulfurization products. These materials are either used in environmental and industrial applications or stored adjacent to power plants. The development of new techniques to track and understand the behavior of CUB in the environment is essential to the safe utilization of coal. In this research, sequential leaching techniques are coupled with strontium (Sr) isotope analysis to investigate the influence of coal type and combustion process on the geochemical characteristics of CUB. Sequential leaches of water, acetic acid, and hydrochloric acid were carried out on a variety of CUB types. Systematic differences in 87Sr/86Sr ratios were observed (1) among different types of CUB, and (2) between leachates and their corresponding bulk CUB values. These differences can help elucidate the origins of the inorganic components of coal, as well as the transformations that occur during combustion. In addition, this study demonstrates for the first time that there are multiple sources of Sr in coal that remain isotopically distinct during combustion. The degree of isotopic homogenization induced during the formation of CUB appears to be controlled by the feed coal chemistry and the particular combustion technology used. The Sr isotope data, when combined with major and trace element results, suggest that a greater fraction of Sr is bound in detrital minerals in higher-rank coals, while authigenic minerals and organic complexes comprise the dominant form of Sr in lower-rank coals. Investigation of CUB produced from fluidized bed combustion (FBC) also demonstrates that the combustion process can strongly impact the behavior of the inorganic components of coal during utilization. The association of potentially toxic trace elements with certain soluble Sr-bearing phases in CUB make Sr isotopes a promising tool to trace the release of these species during interactions with water. Application of Sr isotopes to studies of coal and CUB could facilitate the development of better disposal techniques by serving as a robust tracer of CUB in the environment.

Paleosols, or fossil soils, document past atmospheric composition, climate, and terrestrial landscapes and are key to understanding the composition and evolution of the Earths atmosphere and the environments in which life developed and evolved. Micromorphological, geochemical and isotopic studies of two Precambrian weathering profiles (Steep Rock, Canada and Hokkalampi, Finland) place constraints on the age of soil formation, document pedogenic processes and post-pedogenic alteration and metamorphism, and yield information about the terrestrial environment at a critical time in Earth history. The textures and geochemistry of the Early Proterozoic Hokkalampi paleosol and the Archean Steep Rock paleosol are consistent with in situ, subaerial weathering under varying soil redox conditions. The upper portion of both profiles have lost greater than 40% of their iron relative to the parent material, similar to Phanerozoic vertisols, while retaining Fe3+/Fe2+ ratios greater than 1. Redistribution of phosphorus in the Steep Rock profile and thorium in some Hokkalampi profiles suggests that organic ligands could have enhanced the mobility of redox-sensitive elements. In addition, copper mobility in the Steep Rock profile could indicate the presence of oxygen in the soil. Loss of base cations in both paleosols is similar to modern ultisols or oxisols, which form in warm, moist environments. Whole rock Rb-Sr isochrons indicate that post-pedogenic potassium metasomatism affected both weathering profiles, and the apparent ages are consistent with the timing of regional greenschist metamorphic events. Whole rock Sm-Nd isotope data demonstrate that rare earth element (REE) systematics were largely unaffected by metamorphism, and that the observed mobility and fractionation of REE could represent a record of Precambrian weathering processes. In the Hokkalampi profiles, Sm-Nd isotope data suggest that pedogenesis took place 2.35±0.19 Ga; this also places a minimum age for Huronian glaciation in the area. The Sm-Nd age of 3.02±0.09 Ga for the Steep Rock paleosol suggests that pedogenesis occurred very soon (less than 60 Ma) after emplacement and erosional uplift of the parent granitoid. This study demonstrates that Rb-Sr and Sm-Nd analysis combined with geochemical, field, and microscopic examination of Precambrian paleosols can help constrain the nature and timing of ancient Earth-surface processes.

Two research projects by the Water and Energy Team of the National Energy Technology Laboratory were carried out in collaboration between the US Department of Energy and the University of Pittsburgh. Both projects are related to investigating current and potential impacts of abandoned coal mines on the adjacent populated regions. The first project was carried out in West Virginia over 14 active and abandoned coal slurry impoundments (Appendix A) in order to remotely investigate their current condition and potential hazards related to the mine-waste pools. Three main scenarios of impoundment failure are overtopping of the impoundment, internal erosion (piping) and entry of unconsolidated material into adjacent mine voids due to subsidence. To characterize these potential hazards, helicopter-mounted electromagnetic (HEM) surveys were completed to identify fluid saturated zones within coal waste and to delineate the paths of filtrate fluid flow. Attempts were also made to identify flooded mine workings underlying the impoundment areas. A total of 431 flight lines were processed, each from 2 to over 4 km in length, in total more than 1300 line-kilometers of HEM survey. Follow-up, ground-based resistivity surveys verified the results of the HEM investigations. The HEM and ground-based geophysical surveys proved to be effective in delineating the phreatic surface, determining seep locations, imaging areas of unconsolidated slurry, locating areas where process water has invaded adjacent aquifers, potentially depicting the possible location of flooded underground mine workings and locating infiltration zones. The second project took place in southwestern Pennsylvania. In order to image beneath the surface and identify zones of possible gas accumulation and migration routes, reflection seismic surveys were completed in this area. Seismic imaging was successful in identifying regions of subsurface gas accumulation. Because of the urban nature of the survey, it was very challenging to collect and process seismic reflection data.

Mount Edziza Volcanic Complex (MEVC) lies within the Northern Cordilleran Volcanic Province (NCVP), in northwest British Columbia, Canada. The eruption products have been emplaced in a variety of subaerial, sub-ice and subaqueous environments from about 8Ma to less than 2000 y.b.p. (Souther, 1992). Ice Peak Formation (IPF) trachyte lava flows of approximately 1Ma age (Souther, 1992) are exposed at Ornostay Bluff (OB) and Koosick Bluff (KB). These flows comprise basal flow breccias overlain by massive conchoidally-fractured lava with large, poorly-developed columns, and local flow banding. Edziza Formation (EF) approximately 1Ma (Souther, 1992) phonolite is exposed at Triangle Dome (TD). TD can broadly be divided into an upper and lower zone. The upper zone comprises poorly-developed columns in addition to prominent jointing. In the lower zone the columns are planar and 75cm-3m-wide in the interior of the complex grading into fan-like and curved subhorizontal columns <75cm-wide in the outer margins of the lower zone. The upper zone is interpreted as an entablature where slow cooling was overprinted by joints formed during abrupt cooling due to water ingress. Local areas with well-developed columnar jointing in the upper zone may reflect endogenous growth by late-stage intrusive emplacement, or areas where water ingress was less efficient. The lower zone is interpreted as a lower colonnade with slower cooling and less water ingress during cooling. The fan-like columns in the outer margins of the lower zone reflect cooling by direct contact with curved margins of the ice cavity. The estimated minimum thickness of the ice-contact zone is ~60m reflected by the thickness of the lower zone. Identifying ice-contact structures in trachytic-phonolitic lavas is difficult, especially in glacially eroded examples such as OB and KB, where marginal cooling-columns and structures caused by direct contact with ice have been eroded. Trachyte lavas display a wide range of viscosities, flow thicknesses, and aspect ratios therefore caution is required in interpreting overthick flows as having formed by confinement by former ice. Studies that focus on comparisons of estimated flow velocities and rates of ice melting are useful, though there are numerous unaccounted for variables in these models.

In this thesis, hydrologic mapping and modeling of valley networks using Landsat 7 resolution images and SRTM (Shuttle Radar Topography Mission) derived topographic data are used to quantitatively characterize surface fluvial systems. These stream network models are then used to analyze the role of water in the evolution of the Kuwait region. SRTM-derived Digital Elevation Models (DEM) were combined to build a regional DEM mosaic for the Kuwait region, which was the basis for this analysis. This dataset was analyzed using surface hydrological analysis tools within ArcGIS 9.1 to calculate and model drainage basin geometry and surface stream networks in order to determine basin and network parameters for this region. Stream Order was determined for our stream network model using the Strahler method of ordering. In the study region, a well developed stream network ranging from first to fifth Strahler orders was identified and modeled, defining regions for future investigation of paleochannels created during a paleo climatic wetter period. This model indicates spatial regions within which further research and field investigation are required to analyze the sedimentary deposits in these modeled streams to identify the mechanism and environment of formation.

Bezymianny (55.98°N, 160.59°E) is a Holocene andesitic composite volcano with a summit elevation of approximately 2,900 m and is located on the Kamchatka Peninsula, eastern Russia. Previously inactive for about 1,000 years, Bezymianny reactivated in 1955, culminating in a cataclysmic eruption on 30 March 1956. This directed blast generated a 1.3 km (northsouth) by 2.8 km (eastwest) horseshoe shaped crater opening to the east, similar in morphology and activity to Mt. St. Helens (USA). During the last 30 years Bezymianny has been regularly active, erupting one to two times per year on average. This work focuses on field-based and remote sensing observations of explosive eruptions and their products at Bezymianny, concentrating on the pyroclastic flow (PF) deposits on the southeast flank. The events of March 2000, January 2005, December 2006, May 2007 and October 2007 were focused on to elucidate information on the pyroclastic flow (PF) deposits that were emplaced. Two principal themes were addressed: (1) A thermal infrared (TIR) investigation of the eruptive events and products. This encompassed ground-based field work, Forward Looking Infrared Radiometer (FLIR) image data, and spaceborne data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). (2) A micrometer-scale textural investigation of vesicular block and ash samples collected in the field on the pyroclastic flow deposits. Scanning Electron Microscope (SEM) images were used to generate micron-scale digital elevation models (DEM) for the surfaces of each volcanic sample collected. These were compared to TIR emission spectra that were deconvolved to estimate surface vesicularity. This work demonstrates the utility of TIR observations from satellite, aerial, and ground-based data that, in combination with standard geological mapping, provide timely, accurate, and quantitative remote sensing data to assist in the prediction and monitoring of explosive volcanoes.