The Wyoming Transect: What, Where, How, and Why

Donald S. Stone
Independent, Littleton, CO

The Wyoming Transect is a detailed structural cross section across the state of Wyoming, originally drawn at a scale of 1: 24,000 (1in = 2000 ft). It begins at the South Dakota-Wyoming border and extends southwest some 400 miles to the Idaho border, traversing the northern Black Hills, Powder River, Big Horn, Wind River, and Green River basins and the intervening mountain ranges, ending in the Wyoming thrust belt. An extensive data base was used in construction, including published geologic and commercial photogeological mapping, data from 150 deep wells, and considerable proprietary seismic data through critical parts of the basins and across the thrusted mountain fronts. The Transect provides a foundation for analyzing structural relationships on both a regional and local scale.

In this presentation I will review the elements of the “basement-involved thrust-generated fold” model that is incorporated in Transect construction and briefly discuss the geology of the oil and gas fields and thrusted mountain uplifts along the line of section.

The 15 individual segments of the original colored Transect have been digitally scanned and saved on two DVDs, copies of which are packaged together with a pre-folded, colored hard copy of the full-length Transect at a scale of 1: 96,000 (1in = 8000 ft). Also on the DVDs is a description of the method of construction and the data base (including a well list), a topographic strip map along the bottom of each Segment showing the exact line of section, and relevant well locations, a Stratigraphic Legend, and a list of References for each Segment. Transect sales are handled by the Rocky Mountain Association of Geologists and all net proceeds are funding the newly established Stone/Hollberg Graduate Scholarship in Structural Geology, to be administered by the RMAG Foundation

AAPG Search and Discovery Article #90092©2009 AAPG Rocky Mountain Section, July 9-11, 2008, Denver, Colorado