Evidence from ophiolites, blueschists, and ultrahigh-pressure metamorphic terranes that the modern episode of subduction tectonics began in Neoproterozoic time

Abstract

Research Article| July 01, 2005 Evidence from ophiolites, blueschists, and ultrahigh-pressure metamorphic terranes that the modern episode of subduction tectonics began in Neoproterozoic time Robert J. Stern Robert J. Stern 1University of Texas, Dallas, Geosciences Department, P.O. Box 830688, 2601 North Floyd Road, Richardson, Texas 75083-0688, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Robert J. Stern 1University of Texas, Dallas, Geosciences Department, P.O. Box 830688, 2601 North Floyd Road, Richardson, Texas 75083-0688, USA Publisher: Geological Society of America Received: 16 Nov 2004 Revision Received: 31 Jan 2005 Accepted: 04 Feb 2005 First Online: 02 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2005) 33 (7): 557–560. https://doi.org/10.1130/G21365.1 Article history Received: 16 Nov 2004 Revision Received: 31 Jan 2005 Accepted: 04 Feb 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 Robert J. Stern; Evidence from ophiolites, blueschists, and ultrahigh-pressure metamorphic terranes that the modern episode of subduction tectonics began in Neoproterozoic time. Geology 2005;; 33 (7): 557–560. doi: https://doi.org/10.1130/G21365.1 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 Earth is the only known planet with subduction zones and plate tectonics, and this fact demonstrates that special conditions are required for this mode of planetary heat loss. Sinking of cold, dense lithosphere in subduction zones is the principal plate-driving force, so plate tectonics could not have begun until Earth cooled sufficiently to allow lithosphere to collapse into the underlying asthenosphere. Direct geologic evidence for when the modern episode of subduction tectonics began focuses on the first appearance of ophiolitic graveyards, blueschist facies metamorphic rocks, and ultrahigh-pressure metamorphic terranes. Ophiolites manifest two modes of lithospheric motion expected from subduction tectonics: seafloor spreading and obduction. High-pressure, low-temperature metamorphic blueschists and ultrahigh-pressure terranes indicate subduction and exhumation of oceanic and continental crust, respectively. These lines of evidence indicate that the modern style of subduction tectonics began in Neoproterozoic time. This revolution in the functioning of the solid Earth may have driven wild fluctuations in Earth's climate, described under the "snowball Earth" hypothesis. These conclusions may be controversial, but suggest fruitful avenues for research in geodynamics and paleoclimate. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.