About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 40 (1956)

Issue: 4. (April)

First Page: 562

Last Page: 599

Title: Marine Jurassic Exposed in Bighorn Basin, Pryor Mountains, and Northern Bighorn Mountains, Wyoming and Montana

Author(s): Ralph W. Imlay (2)


The marine Jurassic rocks exposed in the Bighorn Basin in north-central Wyoming and in adjoining parts of Montana are, for purposes of this paper, divided into three major units, of which those in Wyoming are the approximate lithic and time equivalents of those in Montana. The lowest is of Middle Jurassic age, the middle of early Callovian age, and the upper of Oxfordian age. These units, according to the writer's interpretation, represent three distinct marine invasions that are separated by intervals of erosion during late Bathonian and late Callovian time. Evidence for erosion is particularly well shown in exposures along the east side of the Bighorn Basin. An upwarp in the vicinity of Tensleep influenced sedimentation during Callovian and Oxfordian time and apparently rose above the sea as a low island near the beginning of Callovian time.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].