Electronic Theses and Dissertations

Date

2021

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Earth Sciences

Committee Chair

Christine Powell A Powell

Committee Member

Randel T Cox

Committee Member

Chris Cramer

Committee Member

Mitch Withers

Committee Member

Eunsoe Choi

Abstract

We apply multiple filters to aeromagnetic intensity data to visualize the magnetic signature of eastern Reelfoot rift margin basement rocks. We interpret the eastern Reelfoot rift margin to be segmented into nine intersecting faults. We calculate the moment magnitude potential of each fault based on the estimated fault length. The minimum moment magnitude potential is 6.0, and the maximum is 7.0.The Crittenden County fault zone is a potentially active fault zone located within 25 km of Memphis, Tennessee, and poses a significant seismic hazard to the region. To improve our understanding of the structure of both fault systems in this region, we apply two processing techniques to gridded aeromagnetic data. We use the horizontal gradient method on reduction-to-pole magnetic data to detect magnetic contacts associated with faults. For depth to basement estimations, we use the analytic signal. We suggest that the Crittenden County fault zone extends approximately 16 km further to the southwest than previously mapped and may be composed of three independent faults as opposed to a continuous structure. To the northeast, we interpreted two possible faults associated with the eastern Reelfoot rift margin that intersect the Crittenden County fault zone, one of which has been previously mapped as the Meeman-Shelby Fault. If the Crittenden County fault zone and the eastern rift margin are composed of isolated fault segments, the maximum magnitude earthquake that each fault segment may generate significantly lowers the existing seismic hazard assessment of both fault systems with respect to Memphis, Tennessee. We generate a depth to basement map of the southcentral United States to better understand the basement structures and geologic history of the region. We use two depth estimation techniques on reduced-to-pole magnetic data, the tilt-derivative, and special functions. We identify the Rough Creek graben, the Reelfoot rift, and the Eastern Embayment graben, a previously unidentified graben, from our map. Within both the Reelfoot and Eastern Embayment graben, we classify northwest-trending domain boundaries that may be the crustal boundary between the Eastern Granite Rhyolite Province and the Southern Granite Rhyolite Province.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest

Notes

Open Access

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