Quaternary Faulting beneath Memphis, Tennessee

Abstract

Other| September 01, 2005 Quaternary Faulting beneath Memphis, Tennessee Maria Velasco; Maria Velasco Department of Earth Sciences University of Memphis Memphis, Tennessee 38152 +1-901-678-2177 Fax +1-901-678-2178 rvanrsdl@memphis.edu 1Department of Earth Sciences, University of Memphis Search for other works by this author on: GSW Google Scholar Roy Van Arsdale; Roy Van Arsdale * Department of Earth Sciences University of Memphis Memphis, Tennessee 38152 +1-901-678-2177 Fax +1-901-678-2178 rvanrsdl@memphis.edu 1Department of Earth Sciences, University of Memphis * Corresponding author Search for other works by this author on: GSW Google Scholar Brian Waldron; Brian Waldron Department of Earth Sciences University of Memphis Memphis, Tennessee 38152 +1-901-678-2177 Fax +1-901-678-2178 rvanrsdl@memphis.edu 2Ground Water Institute, University of Memphis Search for other works by this author on: GSW Google Scholar James Harris; James Harris Department of Earth Sciences University of Memphis Memphis, Tennessee 38152 +1-901-678-2177 Fax +1-901-678-2178 rvanrsdl@memphis.edu 3Geology Department, Millsaps College Search for other works by this author on: GSW Google Scholar Randel Cox Randel Cox Department of Earth Sciences University of Memphis Memphis, Tennessee 38152 +1-901-678-2177 Fax +1-901-678-2178 rvanrsdl@memphis.edu 1Department of Earth Sciences, University of Memphis Search for other works by this author on: GSW Google Scholar Seismological Research Letters (2005) 76 (5): 598–614. https://doi.org/10.1785/gssrl.76.5.598 Article history first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Maria Velasco, Roy Van Arsdale, Brian Waldron, James Harris, Randel Cox; Quaternary Faulting beneath Memphis, Tennessee. Seismological Research Letters 2005;; 76 (5): 598–614. doi: https://doi.org/10.1785/gssrl.76.5.598 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySeismological Research Letters Search Advanced Search Abstract A geologic investigation of the city of Memphis and southern Shelby County, Tennessee reveals Quaternary faulting. Structure contour maps and cross-sections of the top of the Pliocene-Pleistocene Upland Complex (Lafayette gravel), Eocene Upper Claiborne Group, and Eocene Lower Claiborne Group reveal two 20-m down-to-the-northwest faults that strike approximately N30°E The western fault is herein called the Memphis Fault and the eastern, the Ellendale Fault.The Ellendale Fault is projected to pass beneath the Wolf River flood plain in east Memphis. At this location, a cut bank exposes flood-plain sands that are folded into an anticline with a wavelength of ∼ 100 m, an amplitude of ∼4 m, and a hinge oriented 10°N7°W. The folded sands are truncated by overlying, flat-lying, clayey silt overbank sediments. A 1-m-wide earthquake liquefaction sand dike was found above the crest of the anticline, in the overbank sediments. 14C dates reveal that the folding occurred between A.D. 390 and 450, and the liquefaction occurred post A.D. 450. Seismic-reflection lines indicate that the fold extends to more than 60 m depth into the Lower Claiborne Group, has a length of more than 1 km, and is thus tectonic in origin. The reflection lines also reveal a N25°E down-to-the-west fault with 5 m of displacement in the Upper Claiborne Group that we believe is within the Ellendale Fault zone. We believe the anticline formed during ∼5 m of Quaternary right-lateral strike-slip movement on the N25°E-trending fault. Based on these observations, we also believe that the Ellendale Fault, and perhaps the Memphis Fault, may pose seismic threats to the city of Memphis and Shelby County, Tennessee. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.