OF-22-16D Digital Compilation of Surficial and Bedrock Geology of the Montrose 30x60 Minute Quadrangle General, Geology, Publications March 30, 2023 New Colorado 30×60 minute quadrangle datasets Underwritten with special supplemental funding though the US Geological Survey (USGS) STATEMAP Program, we digitized, re-compiled, and quality-controlled several previously-published 30×60-minute geologic map quadrangles as GIS data packages. In addition to the information the original 1:100,000-scale maps, data from more recent 1:24,000-scale (7.5 minute) CGS quadrangle mapping was merged…
Munroe Quarry near Livermore Geology, Hazards April 11, 2022 Case Study: Lykins Formation Small but significant areas of Colorado are underlain by bedrock that is composed of evaporative minerals. These are salts and sulfates that precipitate out of salt-concentrated surface waters. In the geologic past these minerals were deposited in shallow seas within closed or restricted basins where…
West view of the 2003 sinkhole showing proximity to campus buildings. Sunlight Ski Area is on the left horizon. Roaring Fork River valley is in left middle background below the ski area and in front of first row of ridges. Photo credit: Jon White for the CGS.|South close-up view of sinkhole wall showing uniform silt sediments derived from windblown deposits (loess). CMC maintenance staff had started to fill the sinkhole with broken road-pavement waste. Photo credit: Jon White for the CGS.|Sample of the loess from the wall of the sinkhole. Photo credit: Jon White for the CGS.|The sinkhole site Geology, Hazards February 4, 2003 Case Study: Colorado Mountain College, Spring Valley In early February of 2003, a 24-foot-wide (7.5 m) sinkhole spontaneously opened on a soccer field at the Colorado Mountain College (CMC) – Spring Valley campus, about 10 miles (16 km) southeast of Glenwood Springs in Garfield County. The CMC physical plant maintenance staff back-filled the hole with road pavement…