The Geologic History of the Black HillsJ. P. GriesE. TullisNorth Dakota Geological Society
Australia - Geologic History: The earliest known manifestations of the geologic record of the Australian continent are 4.4-billion-year-old detrital grains of zircon in metasedimentary rocks that were deposited from 3.7 to 3.3 billion years ago. Based on
I’ve long been drawn to Death Valley. As a geologist, I can’t think of a better place to witness the incredible geologic history that shaped western North America –and as a photographer, I can’t think of a better place to capture images of what’s a mind-boggling array of geologic...
I don’t know the history of this place, but it must have been 1950s swanky in its heyday!… There was also a mountain lion living under the hotel. It startled me. The road forks, and I head West along Elko County Road 746 (the Charleston-Mountain City Road). It’s like any ...
From then until nearly the present, the history of the state was one of erosion. The Pleistocene ice ages brought deep glaciers to the whole state. A surface geologic map, showing the glacial deposits and landforms, would look very different from this one. I have two apologies. First, I...
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GEOLOGIC MAP OF THE BLACKHAWK QUADRANGLE, BLACK HILLS OF SOUTH DAKOTA (1:24,000-SCALE)Urban development is currently covering numerous deposits of sand and gravel, limestone, gypsum, and sandstone. The value of such commodities, and the effect of their long-term loss on the local economy, is...
EDMAP-SPONSORED GEOLOGIC MAPPING IN THE BLACK HILLS DEVELOPMENT CORRIDOR, SOUTH DAKOTAAs a group, these quadrangles are underlain by complexly deformed Proterozoic metamorphic and igneous rocks, a gently east-dipping section of Cambrian through Cretaceous continental and marine strata (deformed by Lara...
The northeast striking faults parallel the Colorado Lineament and underlying Precambrian trends. Other fault orientations parallel a Black Hills trend. Subsequent research and analysis should help reconstruct the deformation events and place them into the geological history of the region and help document...
On-going hydrologic studies in the central Black Hills (funded by the West Dakota Water Development District) are examining individual 7.5 minute quadrangles in order to create an atlas of aquifer characteristics for sedimentary and crystalline rocks. The first step in this effort is the creation ...