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The importance of blueschist → eclogite dehydration reactions in subducting oceanic crust

1993; Geological Society of America; Volume: 105; Issue: 5 Linguagem: Inglês

10.1130/0016-7606(1993)105 2.3.co;2

1943-2674

Simon M. Peacock,

Geochemistry and Geologic Mapping

Research Article| May 01, 1993 The importance of blueschist → eclogite dehydration reactions in subducting oceanic crust SIMON M. PEACOCK SIMON M. PEACOCK 1Department of Geology, Arizona State University, Tempe, Arizona 85287-14042Institut für Mineralogie und Petrographie, ETH Zentrum, CH-8092 Zürich, Switzerland Search for other works by this author on: GSW Google Scholar GSA Bulletin (1993) 105 (5): 684–694. https://doi.org/10.1130/0016-7606(1993)105 2.3.CO;2 Article history first online: 01 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 SIMON M. PEACOCK; The importance of blueschist → eclogite dehydration reactions in subducting oceanic crust. GSA Bulletin 1993;; 105 (5): 684–694. doi: https://doi.org/10.1130/0016-7606(1993)105 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 SocietyGSA Bulletin Search Advanced Search Abstract The metamorphic evolution and dehydration of subducting oceanic crust may be predicted by combining calculated pressure-temperature (P-T) paths with a model of metabasalt phase equilibria. In steady-state subduction zones with high rates of shear heating, the upper parts of the subducting oceanic crust progress through the greenschist → amphibolite → granulite → eclogite facies, whereas lower parts of the subducting oceanic crust progress through the blueschist → eclogite facies. In steady-state subduction zones with moderate rates of shear heating, most of the subducting oceanic crust passes through the blueschist → eclogite transition. In steady-state subduction zones with low rates of shear heating, the entire subducting oceanic crust lies within the blueschist facies to depths greater than 70 km. For oceanic crust containing 1-2 wt% H2O, dehydration will not begin until the onset of eclogite- or amphibolite-facies metamorphism, depending on the P-T path. For many subduction zones, the most important dehydration reactions in the subducting oceanic crust occur at the blueschist → eclogite facies transition associated with the breakdown of lawsonite (or clinozoisite), glaucophane, and chlorite. Large amounts of H2O released by blueschist → eclogite dehydration reactions could trigger partial melting in the overlying mantle wedge and may play a crucial role in the generation of arc magmas. 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.