Hot orogens, tectonic switching, and creation of continental crust

Abstract

Research Article| June 01, 2002 Hot orogens, tectonic switching, and creation of continental crust W.J. Collins W.J. Collins 1Department of Geology, School of Geosciences, University of Newcastle, Newcastle, New South Wales 2308, Australia Search for other works by this author on: GSW Google Scholar Author and Article Information W.J. Collins 1Department of Geology, School of Geosciences, University of Newcastle, Newcastle, New South Wales 2308, Australia Publisher: Geological Society of America Received: 02 Nov 2001 Revision Received: 05 Mar 2002 Accepted: 06 Mar 2002 First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2002) 30 (6): 535–538. https://doi.org/10.1130/0091-7613(2002)030<0535:HOTSAC>2.0.CO;2 Article history Received: 02 Nov 2001 Revision Received: 05 Mar 2002 Accepted: 06 Mar 2002 First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation W.J. Collins; Hot orogens, tectonic switching, and creation of continental crust. Geology 2002;; 30 (6): 535–538. doi: https://doi.org/10.1130/0091-7613(2002)030<0535:HOTSAC>2.0.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 Many granulite terrains were too hot to have formed during continental collision. Rather, along with many high-grade metamorphic terrains that typify continental crust, most formed in accretionary orogens during tectonic switching, when prolonged lithospheric extension was interrupted by intermittent, transient contraction. Based on modern and ancient examples, tectonic switching occurs when slab retreat induces upper plate extension, causing arc splitting, formation of microcontinent slivers, and backarc basins; then intermittent arrival of buoyant oceanic plateaus induces transient flat subduction (or slab flip) and crustal thickening. During slab retreat, basaltic magmas produced from decompressed asthenosphere advect into the extending orogen, causing granulite facies metamorphism and granite generation, but subsequent thickening during flat subduction cools the region. Thickening is focused in the thermally softened backarc region and, if sediment filled, a hot, short-lived (∼10 m.y.), narrow (50– 100 km) orogenic belt forms. Such thickening is often misleadingly ascribed to arc or microcontinent collision. Once slab-retreat mode is reestablished, lithospheric extension recommences and a new arc-backarc system forms, generally outboard. Arrival of another plateau will reverse the procedure, and another short-lived, hot orogen will form within the orogenic system. Cycles of tectonic switching efficiently produce continental crust. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.