Discovery of Paleozoic Fe-Mg carpholite in Motalafjella, Svalbard Caledonides: A milestone for subduction-zone gradients

Research Article| October 01, 2005 Discovery of Paleozoic Fe-Mg carpholite in Motalafjella, Svalbard Caledonides: A milestone for subduction-zone gradients P. Agard; P. Agard 1 Laboratoire de Tectonique, Université Paris VI, Case 129, T46-0, 2E, 4 place Jussieu, 75252 Paris Cedex 5, France Search for other works by this author on: GSW Google Scholar L. Labrousse; L. Labrousse 1 Laboratoire de Tectonique, Université Paris VI, Case 129, T46-0, 2E, 4 place Jussieu, 75252 Paris Cedex 5, France Search for other works by this author on: GSW Google Scholar S. Elvevold; S. Elvevold 2Norwegian Polar Institute, 9296 Tromsø, Norway Search for other works by this author on: GSW Google Scholar C. Lepvrier C. Lepvrier 3Laboratoire de Tectonique, Université Paris VI, Case 129, T46-0, 2E, 4 place Jussieu, 75252 Paris Cedex 5, France Search for other works by this author on: GSW Google Scholar Author and Article Information P. Agard 1 Laboratoire de Tectonique, Université Paris VI, Case 129, T46-0, 2E, 4 place Jussieu, 75252 Paris Cedex 5, France L. Labrousse 1 Laboratoire de Tectonique, Université Paris VI, Case 129, T46-0, 2E, 4 place Jussieu, 75252 Paris Cedex 5, France S. Elvevold 2Norwegian Polar Institute, 9296 Tromsø, Norway C. Lepvrier 3Laboratoire de Tectonique, Université Paris VI, Case 129, T46-0, 2E, 4 place Jussieu, 75252 Paris Cedex 5, France Publisher: Geological Society of America Received: 07 Mar 2005 Revision Received: 30 May 2005 Accepted: 03 Jun 2005 First Online: 03 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (2005) 33 (10): 761–764. https://doi.org/10.1130/G21693.1 Article history Received: 07 Mar 2005 Revision Received: 30 May 2005 Accepted: 03 Jun 2005 First Online: 03 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 P. Agard, L. Labrousse, S. Elvevold, C. Lepvrier; Discovery of Paleozoic Fe-Mg carpholite in Motalafjella, Svalbard Caledonides: A milestone for subduction-zone gradients. Geology 2005;; 33 (10): 761–764. doi: https://doi.org/10.1130/G21693.1 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 Paleozoic blueschist facies rocks are relatively scarce on Earth due to warmer geothermal gradients at that time and/or later reequilibration. Ferro-magnesiocarpholite (Fe-Mg carpholite), the typical low-temperature blueschist facies index mineral in metapelites, was discovered 30 yr ago and is known only in Tethyan belts metamorphosed <80 m.y. ago. Herein we report the discovery of Paleozoic Fe-Mg carpholite in the ca. 470 Ma blueschists of Motalafjella, Svalbard Caledonides, the oldest known occurrence on Earth. The carpholite-bearing rocks reached pressure-temperature (P-T) conditions of 15–16 kbar and 380–400 °C and followed a nearly isothermal exhumation path. In the cooling Earth perspective, these P-T estimates for Motalafjella blueschists demonstrate the existence of cold subduction-zone gradients (∼7 °C/km) from the middle Paleozoic onward. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.