Graduation Year


Date of Thesis Acceptance

Fall 5-11-2011

Major Department or Program



Kevin Pogue


The Bighorn Mountains of north central Wyoming are a basement-cored arch formed during the Laramide Orogeny. Working in association with the Bighorn Arch Seismic Experiment, the Keck Bighorns project seeks to understand the structures within the crystalline basement and sedimentary cover rocks during formation of the arch. Little is known of the origin of the brittle structures within the crystalline rocks at the core of the arch, and distinguishing Laramide-related faults and folds from Precambrian structures is not an easy task. Erosion of these structures has produced topographic lineaments throughout the range. Combined field measurements and GIS-based topographic lineament analysis of outcrop-scale brittle fractures in the crystalline basement and the Edelman Creek and North Paint Rock Creek regional-scale lineaments in the Bighorn Mountains shows that the Edelman and North Paint Rock Creek zones were reactivated as a conjugate strike slip pair of faults under Laramide principal stress. Other topographic lineaments correspond to fracture orientations that may have functioned as subsidiary arrays for these major fault zones. Field data and kinematic and microstructural analyses show that both the Edelman and North Paint Rock Creek zones, and many m- to km-scale faults, are Precambrian structures that were reactivated by Laramide compression. Many Precambrian events that have created these fractures, including the Trans-Hudsonian, Big Sky, and Medicine Bow Orogenies of the Wyoming Province, all of which occurred at about 1.8 Ga.

Page Count


Subject Headings

Topography, Rocks -- Fracture, Sedimentary rocks -- Analysis, Wyoming -- North Paint Rock Creek, Wyoming - Edelman Creek, Bighorn Mountains (Wyo. and Mont.), Faults (Geology), Crystalline rocks, Arches -- Bighorn Arch, Anisotropy, Cloud Peak Wilderness (Wyo.), Outcrops (Geology), Whitman College -- Dissertation collection 2011 -- Geology Department

Permanent URL

Document Type

Public Accessible Thesis

Terms of Use

If you have questions about permitted uses of this content, please contact the ARMINDA administrator

Included in

Geology Commons



Rights Statement

Rights Statement

In Copyright. URI:
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).