Kinematics and geometry of active detachment faulting beneath the Trans-Atlantic Geotraverse (TAG) hydrothermal field on the Mid-Atlantic Ridge

Abstract

Research Article| August 01, 2007 Kinematics and geometry of active detachment faulting beneath the Trans-Atlantic Geotraverse (TAG) hydrothermal field on the Mid-Atlantic Ridge Brian J. deMartin; Brian J. deMartin 1Massachusetts Institute of Technology–Woods Hole Oceanographic Institution Joint Program in Oceanography, Cambridge, Massachusetts 02139, USA Search for other works by this author on: GSW Google Scholar Robert A. Sohn; Robert A. Sohn 2Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA Search for other works by this author on: GSW Google Scholar Juan Pablo Canales; Juan Pablo Canales 2Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA Search for other works by this author on: GSW Google Scholar Susan E. Humphris Susan E. Humphris 2Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Brian J. deMartin 1Massachusetts Institute of Technology–Woods Hole Oceanographic Institution Joint Program in Oceanography, Cambridge, Massachusetts 02139, USA Robert A. Sohn 2Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA Juan Pablo Canales 2Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA Susan E. Humphris 2Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA Publisher: Geological Society of America Received: 21 Nov 2006 Revision Received: 05 Mar 2007 Accepted: 23 Mar 2007 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2007) 35 (8): 711–714. https://doi.org/10.1130/G23718A.1 Article history Received: 21 Nov 2006 Revision Received: 05 Mar 2007 Accepted: 23 Mar 2007 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Brian J. deMartin, Robert A. Sohn, Juan Pablo Canales, Susan E. Humphris; Kinematics and geometry of active detachment faulting beneath the Trans-Atlantic Geotraverse (TAG) hydrothermal field on the Mid-Atlantic Ridge. Geology 2007;; 35 (8): 711–714. doi: https://doi.org/10.1130/G23718A.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 Newly acquired seismic refraction and microearthquake data from the Trans-Atlantic Geotraverse (TAG) segment of the Mid-Atlantic Ridge at 26°N reveal for the first time the geometry and seismic character of an active oceanic detachment fault. Hypocenters from 19,232 microearthquakes observed during an eight month ocean bottom seismometer deployment form an ∼15-km-long, dome-shaped fault surface that penetrates to depths >7 km below the seafloor on a steeply dipping (∼70°) interface. A tomographic model of compressional-wave velocities demonstrates that lower crustal rocks are being exhumed in the detachment footwall, which appears to roll over to a shallow dip of 20° ± 5° and become aseismic at a depth of ∼3 km. Outboard of the detachment the exhumed lithosphere is deformed by ridge-parallel, antithetical normal faulting. Our results suggest that hydrothermal fluids at the TAG field exploit the detachment fault to extract heat from a region near the crust-mantle interface over long periods of time. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.