A contrast in anisotropy across mid-lithospheric discontinuities beneath the central United States—A relic of craton formation

Research Article| October 01, 2014 A contrast in anisotropy across mid-lithospheric discontinuities beneath the central United States—A relic of craton formation Erin A. Wirth; Erin A. Wirth * Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06511, USA *E-mail: erin.wirth@yale.edu. Search for other works by this author on: GSW Google Scholar Maureen D. Long Maureen D. Long Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06511, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Erin A. Wirth * Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06511, USA Maureen D. Long Department of Geology and Geophysics, Yale University, New Haven, Connecticut 06511, USA *E-mail: erin.wirth@yale.edu. Publisher: Geological Society of America Received: 24 Apr 2014 Revision Received: 14 Jul 2014 Accepted: 16 Jul 2014 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2014 Geological Society of America Geology (2014) 42 (10): 851–854. https://doi.org/10.1130/G35804.1 Article history Received: 24 Apr 2014 Revision Received: 14 Jul 2014 Accepted: 16 Jul 2014 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Erin A. Wirth, Maureen D. Long; A contrast in anisotropy across mid-lithospheric discontinuities beneath the central United States—A relic of craton formation. Geology 2014;; 42 (10): 851–854. doi: https://doi.org/10.1130/G35804.1 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 SocietyGeology Search Advanced Search Abstract The mid-lithospheric discontinuity (MLD) is a seemingly sharp decrease in seismic velocity at depths internal to the lithosphere and appears to be a pervasive feature beneath continental interiors. Its presence within cratons, which have remained relatively stable since formation, suggests that the MLD may result from processes associated with continent formation. We use P- to S-wave receiver functions to interrogate seismic anisotropy across the MLD within the ca. 1.35–1.55 Ga Granite-Rhyolite Province of the central United States. Our analysis reveals strong evidence for sharp changes in the orientation of anisotropy across multiple MLDs, with an approximately north to northwest fast orientation of anisotropy in the upper lithosphere. The consistency of this signature over a large region suggests that the observed anisotropy is a relic of North American craton formation. In addition, the presence of several distinct anisotropic layers within the cratonic lithosphere supports models for craton formation via stacked subducted slabs or a series of underthrusting events. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.