Linkage of Laramide Depositional and Deformational Histories of the Sweetwater Arch and Adjacent Parts of the Hanna Basin, Wyoming

University Of Wyoming, Laramie WY

Investigators

Abstract

Linkage of Laramide depositional and deformational histories of the Sweetwater arch and adjacent parts of the Hanna Basin, Wyoming Jason A. Lillegraven and Arthur W. Snoke, Co-Principal Investigators This is a renewal grant to integrate evidence from paleontological and surface-structural studies along margins of the Hanna Basin of south-central Wyoming. Key goals are to explore geometric and temporal relationships between oppositely directed thrust systems and to test structural models of linkage and interaction between basement-involved uplifts and thin-skinned, out-of-the-basin faulting. This Group Grant is collaborative among the University of Wyoming (J. A. Lillegraven, A. W. Snoke, W. S. Holbrook, and their students), American Museum of Natural History (M. C. McKenna), University of Colorado (J. G. Honey), and the petroleum industry (geologists and geophysicists at Marathon Oil Company). New elements are integration of seismic-lines from industry across various structurally complex margins of the Hanna Basin. Integration of seismic-reflection data, we believe, represents the only satisfactory means to grasping details of the nature of basement-involvement (within uplifts and at the floor of a deep basin) in evolution of Laramide basin-uplift interfaces. We suggest that this tiny part of the Rocky Mountains provides an excellent setting in which to study fundamentally important crustal-scale processes that occurred during regional contraction, including greater appreciation for the influence and magnitude of basement-involved blind thrusting. Vertebrate biostratigraphy, linked to continued surface mapping, is seminal to constraining timing of steps within Laramide basinal subdivision and associated deformation.