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Research Article| August 01, 2010 Mesoarchean subduction processes: 2.87 Ga eclogites from the Kola Peninsula, Russia M.V. Mints; M.V. Mints 1Geological Institute of Russian Academy of Sciences, Moscow 119017, Russia Search for other works by this author on: GSW Google Scholar E.A. Belousova; E.A. Belousova 2GEMOC ARC National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, NSW 2109, Australia Search for other works by this author on: GSW Google Scholar A.N. Konilov; A.N. Konilov 1Geological Institute of Russian Academy of Sciences, Moscow 119017, Russia Search for other works by this author on: GSW Google Scholar L.M. Natapov; L.M. Natapov 2GEMOC ARC National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, NSW 2109, Australia Search for other works by this author on: GSW Google Scholar A.A. Shchipansky; A.A. Shchipansky 1Geological Institute of Russian Academy of Sciences, Moscow 119017, Russia Search for other works by this author on: GSW Google Scholar W.L. Griffin; W.L. Griffin 2GEMOC ARC National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, NSW 2109, Australia Search for other works by this author on: GSW Google Scholar S.Y. O'Reilly; S.Y. O'Reilly 2GEMOC ARC National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, NSW 2109, Australia Search for other works by this author on: GSW Google Scholar K.A. Dokukina; K.A. Dokukina 1Geological Institute of Russian Academy of Sciences, Moscow 119017, Russia Search for other works by this author on: GSW Google Scholar T.V. Kaulina T.V. Kaulina 3Geological Institute of the Kola Science Centre RAS, Apatity 184209, Russia Search for other works by this author on: GSW Google Scholar Geology (2010) 38 (8): 739–742. https://doi.org/10.1130/G31219.1 Article history received: 02 Nov 2009 rev-recd: 17 Mar 2010 accepted: 20 Mar 2010 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation M.V. Mints, E.A. Belousova, A.N. Konilov, L.M. Natapov, A.A. Shchipansky, W.L. Griffin, S.Y. O'Reilly, K.A. Dokukina, T.V. Kaulina; Mesoarchean subduction processes: 2.87 Ga eclogites from the Kola Peninsula, Russia. Geology 2010;; 38 (8): 739–742. doi: https://doi.org/10.1130/G31219.1 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 The nature of tectonic processes on the early Earth is still controversial. The scarcity of high-pressure metamorphic rocks such as eclogite (the high-pressure equivalent of basalt) in Archean cratons has been used to argue that plate tectonics did not operate until Earth had cooled to a critical point, perhaps around the 2.5 Ga Archean-Proterozoic transition. However, eclogites occur as meter- to kilometer-sized lenses enclosed in Archean gneisses of the Belomorian Province of the Fennoscandian shield. Geochemistry and internal features suggest that the protoliths of the eclogites were interlayered olivine gabbros, troctolites, and Fe-Ti oxide gabbros. Greenschist facies mineral parageneses are enclosed in prograde-zoned eclogite garnets, and peak metamorphic conditions define an apparent thermal gradient (12–15 °C/km), consistent with metamorphism in a warm Archean subduction zone. We show here that these eclogites represent the oldest known high-pressure metamorphic rocks. U-Pb dating and Hf isotope analyses of zircons from the eclogites and a crosscutting felsic vein define a minimum age of 2.87 Ga for the Uzkaya Salma eclogite; a 2.70 Ga age for the Shirokaya Salma eclogite is interpreted as the age of a granulite facies overprint. Thermal overprinting and growth of new zircon also occurred during the Svecofennian (1.9–1.8 Ga) orogeny. These new data imply that plate tectonic processes operated at least locally in late Mesoarchean time. The adakitic nature of the felsic vein suggests that partial melting of hydrated eclogites could produce Archean tonalite-trondhjemite-granodiorite–type magmas. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.