MX Siting Investigation, Gravity Survey - Dugway Valley, Utah.
ERTEC WESTERN INC LONG BEACH CA
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The interpretation of the gravity survey in Dugway Valley indicates two distinct basins separated by a small, shallow, buried ridge. The northern basin is an asymmetrical tilt block which is approximately 1800 feet 549 m deep. The block is bounded on the west by a major north-south normal fault system near the base of the Dugway Range. The southern basin is interpreted to partly comprise a collapsed, highly fractured, Tertiary caldera complex. The gravity indicates the caldera volcanics are accumulated to a thickness of about 3500 feet 1067 m thick in a northwesterly trending trough. This caldera complex is transected by later Basin and Range, north-south trending faults systems. A narrow bedrock ridge or horst extends south from the Keg Mountains at a depth of about 2000 feet 610 m. This ridge could restrict groundwater movement between southern Dugway Valley and Sevier Desert Valley. An average density contrast of -0.40 gcu cm between the alluvium-volcanic fill material and the Paleozoic carbonate bedrock was used to calculate the Valley depth.
- Geology, Geochemistry and Mineralogy