Date Thesis Awarded

4-2010

Document Type

Honors Thesis

Degree Name

Bachelors of Science (BS)

Department

Geology

Advisor

Christopher M. Bailey

Committee Member

Ryan Thigpen

Committee Member

Michael Kordosky

Abstract

The tectonic processes of supercontinent breakup create rift structures that are often preserved along the passive margin of continents. The resultant structures and rocks are the foundation from which collisional orogenic structures are eventually created. At Sugar Hollow, 15km northwest of Charlottesville, Virginia, ancient Iapetan rift structures are preserved on the eastern margin of Laurentia in the Virginia Blue Ridge. This location preserves a ~10km2 eastward-thickening graben complex consisting of 8 originally-normal faults that reaches a maximum thickness of ~300m. Some of the 8 faults were reactivated past the null point during the Paleozoic producing apparent thrust geometry. To better understand the original structures that accommodated the opening of the Iapetan Ocean at the close of the Neoproterozoic, the basin was restored to its post-rift state using Midland Valley's Move software. During this process, layers were unfolded and fault blocks were restored to their maximum extensional state, revealing ~12% shortening. However, penetrative ductile deformation was not accounted for during this restoration. Therefore, strain and vorticity analysis were used to better understand the intensity and geometry of ductile deformation across the basin. Using this data, a fully restored 3D model of the Sugar Hollow basin was created. This model revealed additional shortening of ~13%, suggesting that penetrative strain may be at least as important of a restoration consideration as faulting and folding. Consequently, strain and vorticity analysis should be integrated into cross section restoration whenever possible.

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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