Year of Award
Master of Science (MS)
Department or School/College
Department of Geosciences
Marc Hendrix, Michael Hofmann, Micahel DeGrandpre
Frontier Formation, Wall Creek Member, Powder River Basin, Tisdale Anticline, Lateral Heterogeneity
University of Montana
Geology | Sedimentology | Stratigraphy
The Upper Turonian Wall Creek Member (WCM) of the Frontier Formation is part of a series of marine sandstones that were deposited on the western flank of the Cretaceous Western Interior Seaway (KWIS). The KWIS was a low accommodation shallow-marine foreland basin system that included many large deltaic complexes on its western margin. Deposition of WCM deltaic deposits was strongly influenced by fourthorder glacioeustatic cycles, oceanographic circulation patterns, and tectonics related to the active Sevier fold and thrust belt to the west. An in-depth field study of the WCM was performed on the western flank of the Powder River Basin (PRB), WY, in exposures forming the eastern flank of the Tisdale Anticline, a Laramide structure. The goal of the field study is to document the lateral and vertical heterogeneities within the WCM sandstone, its architectural elements, and its stratigraphic surfaces and use these to develop a sequence stratigraphic framework. Results of this study improve the understanding of depositional processes of the WCM and its characterization as a petroleum reservoir within ~30km of active drilling and production of the WCM in the PRB. This study describes 8 facies: 1) laminated mudstone 2) interbedded siltstone and sandstone 3) hummocky cross-stratification 4) low-angle stratified sandstone 5) thinly interbedded sandstone and siltstone 6) heterolithic cross-bedded sandstone 7) mediumgrained heterolithic cross-bedded sandstone and 8) trough cross-bedded sandstone. These facies are consolidated into 4 facies associations: FA1) prodelta FA2) distal delta front FA3) middle delta front FA4) tidal bars/shoals. Facies characteristics, facies stacking patterns, and architectural surfaces/elements indicate two primary deltaic influences: 1) storm/wave dominated deltas and 2) tidally dominated deltas. Three incomplete stratigraphic sequences are observed from facies stacking patterns and stratal geometries. Sequence 1) transgressive systems tract 1 (TST1), highstand systems tract 1 (HST1), and falling stage systems tract 1 (FSST1); Sequence 2) transgressive systems tract 2 (TST2) and highstand systems tract 2 (HST2); Sequence 3) lowstand systems tract 1 (LST1).
Zupanic, John, "LATERAL HETEROGENEITY AND ARCHITECTURAL ANALYSIS OF THE WALL CREEK MEMBER OF THE UPPER CRETACEOUS (TURONIAN) FRONTIER FORMATION" (2017). Graduate Student Theses, Dissertations, & Professional Papers. 11033.
© Copyright 2017 John Zupanic