Early Miocene mammals

31 p. : ill., maps ; 24 cm.Includes bibliographical references (p. 29-31)."Fossil mammals of early Miocene age have been found in strata composing Darton's Bluff on the crest of the Bighorn Mountains in the Hazelton Peak Quadrangle, Johnson County, Wyoming. Dating the host strata provides a reference datum for the reconstruction of regional sedimentation during early Miocene time and for determination of the maximum age of epeirogenic uplift. As a result of regional aggradation, the Bighorn Basin was filled with sediments. These buried the rugged peaks and canyons of the Bighorn Mountains up to a level corresponding to the present 9000-foot altitude during early Miocene time. The lower Miocene and older rocks are beveled by the subsummit surface, a remarkably flat and even surface of Miocene or Pliocene age. Excavation of the Bighorn and Powder River basins and exhumation of the Bighorn Mountains must have been accomplished during the relatively short interval of late Cenozoic time after the subsummit surface was cut"--P. [1]

Norfolk folio, Virginia-North Carolina

Norfolk folio, Virginia-North Carolin

Geology and underground waters of the Arkansas Valley in eastern Colorado,

Mode of access: Internet

Deming folio, New Mexico

Deming folio, New Mexic

Syracuse-Lakin folio, Kansas

Syracuse-Lakin folio, Kansa

Guidebook of the Western United States. Part F: The Southern Pacific Lines, New Orleans to Los Angeles

Bulletin 845. Col. Ill. Maps. Includes bibliographic references. Index of place names follows

Oelrichs folio, South Dakota-Nebraska

Oelrichs folio, South Dakota-Nebrask

Scotts Bluff folio, Nebraska

Scotts Bluff folio, Nebrask

Belle Fourche folio, South Dakota

Belle Fourche folio, South Dakot

Passaic folio, New Jersey--New York

Passaic folio, New Jersey--New Yor