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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 51 (1967)

Issue: 9. (September)

First Page: 1904

Last Page: 1904

Title: Permian System of Southern Rocky Mountains and Surrounding Provinces: ABSTRACT

Author(s): James A. Momper

Article Type: Meeting abstract


The Permian Period lasted approximately 50 m.y., beginning 275 m.y. ago. The sedimentary rocks of this system have been divided into four series in the western United States. Despite the scarcity of datable fossils, series correlations generally are reliable except in the piedmont and intermontane redbed facies.

The basal Wolfcamp Series is more extensive and thicker, on the average, than any of the other series. The Ochoa Series, the youngest, essentially is confined to the Permian basin, the Anadarko-Hugoton area and the Great Basin. The Guadalupe Series extends well beyond the erosional limits of the underlying Leonard Series in the northern Great Plains but is absent on much of the Colorado Plateau where the Leonard is well preserved.

A regional unconformity, usually of low Previous HitangleNext Hit, separates Permian rocks from the Pennsylvanian System, even where the Virgil Series of Late Pennsylvanian age underlies the Wolfcamp. It is believed that late Virgilian-early Wolfcampian time is not represented in most of the region. The Triassic System also is separated from the Permian by a regional low-Previous HitangleNext Hit unconformity. Rocks of Early Triassic age are missing by nondeposition or erosion in part all of the southern structural provinces where the Ochoa is present.

Detailed studies also indicate the presence of interseries unconformities of regional extent. Lower Leonard, lower Guadalupe, and lower Ochoa rocks have limited areal distribution.

Permian depositional environments ranged from terrestrial-piedmont to deep-marine-basinal. Shelf-marine carbonates generally decrease in importance upward through the system whereas evaporite deposits, including halite, are more Previous HitcommonTop and more widespread.

Permian rocks are the source of considerable mineral wealth including, in addition to petroleum, potash, phosphate, sulfur, and helium. Carbonate and sandstone reservoir rocks of Guadalupian, Leonardian, and Wolfcampian ages have yielded vast quantities of oil and gas, especially in the central Rockies, Great Plains, and Permian basin. Permian source shales in western Wyoming and in the Permian basin were major oil contributors.

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Copyright 1997 American Association of Petroleum Geologists