Date Thesis Awarded

7-2012

Access Type

Honors Thesis -- Access Restricted On-Campus Only

Degree Name

Bachelors of Science (BS)

Department

Geology

Advisor

Christopher M. Bailey

Committee Members

R. Heather Macdonald

Jes Therkelsen

Abstract

The Scottsville Basin in central Virginia is one of the westernmost Mesozoic sedimentary basins formed by continental extension during Pangaean rifting in eastern North America. Structural, stratigraphic, and aeromagnetic data are used to understand the structural geometry of the Scottsville Basin. The basin is developed across the Paleozoic Bowens Creek/Mountain Run fault zones that form the boundary between the Western Piedmont and eastern Blue Ridge. This small basin is a 130 km2 half-graben structure bounded in the west by a segmented normal fault. The eastern boundary, previously interpreted as a shallow displacement normal fault, is an unconformable contact with prerift Paleozoic metamorphic rock. The basin is bounded at its northern and southern extent by a distinct "fish mouth" geometry that is likely related to normal faults that cut into the basin. Strata within the basin are tilted perpendicular to the western boundary fault, broadly increasing in dip angle from west to east. This trend suggests syndepositional rifting. A suite of north-northwest striking Jurassic diabase dikes cross-cut the region and are subparallel to the dominant extensional fracture set that cuts basin sedimentary rocks. The orientation of maximum extension appears to have rotated by as much as sixty degrees between basin formation in the Triassic and dike emplacement in the early Jurassic. Although several Mesozoic basins of the central Atlantic margin were tectonically inverted, structural and stratigraphic features in the Scottsville Basin are inconsistent with contractional inversion. It is possible that the magnitude of early Jurassic compressional stress waned from east to west, affecting the Scottsville Basin less than basins further east.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.

Comments

Thesis is part of Honors ETD pilot project, 2008-2013. Migrated from Dspace in 2016.

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