Width of mantle deformation across a continental transform: Evidence from upper mantle (Pn) seismic anisotropy measurements

Research Article| September 01, 2005 Width of mantle deformation across a continental transform: Evidence from upper mantle (Pn) seismic anisotropy measurements Guy Baldock; Guy Baldock 1Institute of Geophysics and School of Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6001, New Zealand Search for other works by this author on: GSW Google Scholar Tim Stern Tim Stern 1Institute of Geophysics and School of Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6001, New Zealand Search for other works by this author on: GSW Google Scholar Author and Article Information Guy Baldock 1Institute of Geophysics and School of Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6001, New Zealand Tim Stern 1Institute of Geophysics and School of Earth Sciences, Victoria University of Wellington, P.O. Box 600, Wellington 6001, New Zealand Publisher: Geological Society of America Received: 09 Feb 2005 Revision Received: 10 May 2005 Accepted: 25 May 2005 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2005) 33 (9): 741–744. https://doi.org/10.1130/G21605.1 Article history Received: 09 Feb 2005 Revision Received: 10 May 2005 Accepted: 25 May 2005 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Guy Baldock, Tim Stern; Width of mantle deformation across a continental transform: Evidence from upper mantle (Pn) seismic anisotropy measurements. Geology 2005;; 33 (9): 741–744. doi: https://doi.org/10.1130/G21605.1 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 Seismic anisotropy (δVp) of at least 6.5% ± 2.5% in the upper mantle (Pn phase) is reported 200 km east of the Alpine fault in South Island, New Zealand. When these new data are combined with a previous Pn study and published SKS splitting results, two distinct domains of mantle deformation are inferred within South Island. In southern South Island, the deforming zone in the mantle lithosphere is as wide as 335 km, whereas in mid–South Island the deforming zone narrows to ∼200 km. Both regions display wider zones of seismic anisotropy than found at other continental transforms of the world. The width and orientation of mantle anisotropy in southern South Island are consistent with a model of simple shear in a zone that has undergone ∼800 ± 200 km of right-lateral shear displacement—a value close to that predicted by geological reconstructions. Hence displacement can be accommodated by distributed shear without faulting being required in the mantle. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.