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Bedrock topography of northwest Iowa Bedrock topography of northwest Iowa
Bedrock in Iowa (Hershey, 1969) generally is overlain by deposits of glacial drive and alluvium. The drift, consisting of glacial till and glacial outwash, ranges in thickness from zero to more than 500 feet in western Iowa; the alluvium in stream valleys ranges in thickness from less than 1 foot to more than 70 feet. The configuration of the bedrock surface is the result of a complex...
Bedrock topography of west-central Iowa Bedrock topography of west-central Iowa
Bedrock in Iowa (Hershey 1969) generally is overlain by deposits of glacial drift and alluvium. The drift, consisting of glacial till and glacial outwash, ranges in thickness from zero to more than 500 feet in western Iowa; the alluvium in stream valleys ranges in thickness from less than 1 to more than 70 feet. The configuration of the bedrock surface is the result of a long period of...
Complete Bouguer gravity and aeromagnetic maps of the Rattlesnake Roadless Area, Missoula County, Montana Complete Bouguer gravity and aeromagnetic maps of the Rattlesnake Roadless Area, Missoula County, Montana
The Rattlesnake Roadless Area was identified by the U.S. Forest Service as a possible addition to the Wilderness System. This 120 square mile area is north of Missoula, Mont. (see index map); Rattlesnake Creek forms the major drainage to the south. The rocks in the study area consist mainly of the Helena Formation and the Missoula Group of the Belt Supergroup (Proterozoic Y). Rock units...