Submission Title

356— Conodonts, Microtektites, and Thermal Alteration, of the Jefferson Formation, Upper Devonian, Wyoming

Submission Type

Poster

Start Date

April 2021

Abstract

The Jefferson Formation, composed of two members, a limestone and dolomite dominated layer called the lower member, and the dolomite-dominated Birdbear Member, is distributed throughout southern Montana and northern Wyoming. Samples were taken from multiple levels within the Birdbear Member, dissolved in buffered 10% formic acid, and the insoluble residue separated using heavy liquid. The heavy fraction was searched for conodonts and microtektites. Conodonts indicate the Middle Frasnian stage of the Upper Devonian and thermal heating of less than 80 degrees Celsius. Microtektites, speculated to occur in the interval corresponding to the Alamo Impact in Nevada, were not found.

Comments

Sponsored by D. Jeffrey Over and Dori Farthing.

https://docs.google.com/presentation/d/11tiymvu8JZ0rViyaanz2EjLIRPgCQQyG4sS829HXzig/edit#slide=id.p1

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COinS
 
Apr 26th, 12:00 AM

356— Conodonts, Microtektites, and Thermal Alteration, of the Jefferson Formation, Upper Devonian, Wyoming

The Jefferson Formation, composed of two members, a limestone and dolomite dominated layer called the lower member, and the dolomite-dominated Birdbear Member, is distributed throughout southern Montana and northern Wyoming. Samples were taken from multiple levels within the Birdbear Member, dissolved in buffered 10% formic acid, and the insoluble residue separated using heavy liquid. The heavy fraction was searched for conodonts and microtektites. Conodonts indicate the Middle Frasnian stage of the Upper Devonian and thermal heating of less than 80 degrees Celsius. Microtektites, speculated to occur in the interval corresponding to the Alamo Impact in Nevada, were not found.