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Australian-Antarctic discordance

1991; Geological Society of America; Volume: 19; Issue: 5 Linguagem: Inglês

10.1130/0091-7613(1991)019 2.3.co;2

1943-2682

Jean‐Christophe Sempéré, Jeb Palmer, David M. Christie, Jason Phipps Morgan, Alexander Shor,

Methane Hydrates and Related Phenomena

Research Article| May 01, 1991 Australian-Antarctic discordance Jean-Christophe Sempeéreé; Jean-Christophe Sempeéreé 1School of Oceanography, University of Washington, Seattle, Washington 98195 Search for other works by this author on: GSW Google Scholar Jeb Palmer; Jeb Palmer 1School of Oceanography, University of Washington, Seattle, Washington 98195 Search for other works by this author on: GSW Google Scholar David M. Christie; David M. Christie 2College of Oceanography, Oregon State University, Corvallis, Oregon 97331-5503 Search for other works by this author on: GSW Google Scholar Jason Phipps Morgan; Jason Phipps Morgan 3Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge Massachusetts 02139 Search for other works by this author on: GSW Google Scholar Alexander N. Shor Alexander N. Shor 4Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 96822 Search for other works by this author on: GSW Google Scholar Geology (1991) 19 (5): 429–432. https://doi.org/10.1130/0091-7613(1991)019 2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jean-Christophe Sempeéreé, Jeb Palmer, David M. Christie, Jason Phipps Morgan, Alexander N. Shor; Australian-Antarctic discordance. Geology 1991;; 19 (5): 429–432. doi: https://doi.org/10.1130/0091-7613(1991)019 2.3.CO;2 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 Australian-Antarctic discordance is a region of anomalous geophysical and geochemical properties along the mid-ocean ridge system. It includes the isotopic boundary between Pacific Ocean and Indian Ocean basalts. Its lavas have compositions consistent with low mantle temperatures and a relatively low overall extent of melting. These characteristics have been attributed to downward flow in the underlying mantle. New bathymetric and side-scan sonar data show that (1) the spreading axis within the discordance is predominantly characterized by a broad rift valley and segmentation characteristics typical of slow-spreading centers, (2) the isotopic boundary appears to be associated with unusual, chaotic sea floor, and (3) the spreading axis east of the discordance is characterized by an axial ridge typical of fast-spreading centers. These extreme variations, at an essentially constant (intermediate) spreading rate are consistent with differences in melt supply and mantle properties along the spreading axis within and east of the discordance, as suggested in previous studies. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.