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A Geomorphological Assessment of Armored Deposits Along the Southern Flanks of Grand Mesa, CO, USABrunk, Timothy J. 2010 May 1900 (has links)
A series of deposits, located along the southern flanks of Grand Mesa, Colorado, and extending to the south, are problematic, and the processes related to emplacement are not understood. The overall area is dominated by two landform systems, Grand Mesa, which supported a Pleistocene ice cap, and the North Fork Gunnison River drainage. Thus, one has to ask: Are these deposits the result of the melting of the ice cap or are they fluvial terraces associated with the evolution of the ancestral Gunnison River? The goal of this research was to map the areal extent of the deposits and to interpret the formation and climatic significance in understanding the evolution of the Pleistocene landscape in the region.
An extensive exposure, parallel to State Highway 65 near Cory Grade, was used for detailed description and sampling. Three additional exposures, ~10 to 20 km (~6 to 12 mi) were used to extend the areal extent of sampling. The study area was mapped using aerial photography and traditional field mapping aided by GPS. From the field work, a detailed stratigraphic column, including lithology and erodability, was constructed. Vertical exposures of the deposits were described, mapped, and recorded in the field and using detailed photo mosaics. Samples were collected from each stratum of the deposits for grain-size, shape, and sorting analyses. Five distinct depositional facies were identified.
Sieve analysis on collected samples shows that four distinct grain-sizes occur in the outcrops; coarse sand, very-coarse sand, granule, and pebble and boulder. Mean grain-sizes range from 0.0722 to 0.9617, -0.0948 to -0.9456, -1.0566 to -1.9053, and -2.0050 to -3.4643, respectively.
Glacio-fluvial depositional environments were identified and supported with observations of sedimentary structures and clast composition. Two major environments of deposition are recorded in the deposits; fluvial deposits from glacial outburst floods, and debris flow deposits. Imbrication of clasts in the strata suggests the flow came from the direction of Grand Mesa to the north. Facies and subsequent sequences were constructed to portray evidence that supports the glacio-fluvial mode of deposition.
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Petroleum Releases from Underground Storage Tanks in Northwest Indiana: Successful Remediation Techniques and Implications of Cost EffectivenessLenz, Richard Jason 13 December 2014 (has links)
Prior to the passage of the 1976 Resource Conservation and Recovery Act (RCRA) 1.6 million bare steel Underground Storage Tanks (UST) were in use in the United States. Many of them were leaking. In Indiana approximately 13,000 UST remain but have been upgraded to meet current industry and regulatory standards. Cleaning up the petroleum releases from leaking UST has continued since it became evident that bare steel underground tanks leaked. In Northwest Indiana glacial moraine and outwash deposits from the Wisconsin Ice Age that retreated 10,000 years ago left 200 feet of glacial till above the underlying bedrock. Soil Vapor Extraction (SVE) and Air Sparging (AS) have proven to be effective and provide significant cost savings for remediation in the glacial deposits in Northwest Indiana. Indiana also has the Excess Liability Trust Fund (ELTF) to help pay for and to expedite clean-up of releases from registered UST. Cleaning up petroleum releases requires the appropriate technology for the localized geology, adequate funding, and appropriate guidance from state and federal regulations. This study discusses these issues at three sites in Northwest Indiana to demonstrate how technology, funding, and regulatory compliance must collaborate to work in the field.
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