Early- to mid-Silurian extrusion wedge tectonics in the central Scandinavian Caledonides

Abstract

Research Article| April 01, 2015 Early- to mid-Silurian extrusion wedge tectonics in the central Scandinavian Caledonides Jens C. Grimmer; Jens C. Grimmer 1Institute of Applied Geosciences, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany Search for other works by this author on: GSW Google Scholar Johannes Glodny; Johannes Glodny 2Inorganic and Isotope Geochemistry Section, Chemistry of the Earth Department, GFZ German Research Centre for Geosciences, D-14473 Potsdam, Germany Search for other works by this author on: GSW Google Scholar Kirsten Drüppel; Kirsten Drüppel 1Institute of Applied Geosciences, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany Search for other works by this author on: GSW Google Scholar Reinhard O. Greiling; Reinhard O. Greiling 1Institute of Applied Geosciences, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany Search for other works by this author on: GSW Google Scholar Agnes Kontny Agnes Kontny 1Institute of Applied Geosciences, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany Search for other works by this author on: GSW Google Scholar Author and Article Information Jens C. Grimmer 1Institute of Applied Geosciences, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany Johannes Glodny 2Inorganic and Isotope Geochemistry Section, Chemistry of the Earth Department, GFZ German Research Centre for Geosciences, D-14473 Potsdam, Germany Kirsten Drüppel 1Institute of Applied Geosciences, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany Reinhard O. Greiling 1Institute of Applied Geosciences, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany Agnes Kontny 1Institute of Applied Geosciences, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe, Germany Publisher: Geological Society of America Received: 09 Nov 2014 Revision Received: 23 Jan 2015 Accepted: 27 Jan 2015 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2015 Geological Society of America Geology (2015) 43 (4): 347–350. https://doi.org/10.1130/G36433.1 Article history Received: 09 Nov 2014 Revision Received: 23 Jan 2015 Accepted: 27 Jan 2015 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 Jens C. Grimmer, Johannes Glodny, Kirsten Drüppel, Reinhard O. Greiling, Agnes Kontny; Early- to mid-Silurian extrusion wedge tectonics in the central Scandinavian Caledonides. Geology 2015;; 43 (4): 347–350. doi: https://doi.org/10.1130/G36433.1 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 We present evidence for an extrusion wedge in the Scandian fold-thrust belt of the central Scandinavian Caledonides (Seve nappe complex). Rb-Sr multimineral geochronology in synkinematic assemblages indicates simultaneous movements at the normal-sense roof shear zone and at the reverse-sense floor shear zone between 434 Ma and 429 Ma. A Sm-Nd age of 462 Ma from a mylonitic garnet mica schist documents prograde garnet growth and possible incipient subduction. Pressure-temperature pseudosection calculations provide evidence for eclogite facies metamorphic conditions and nearly isothermal decompression at ∼670 ± 50 °C from 17.5 to 14.5 kbar in garnet-kyanite mica schists during reverse-sense shearing, and from 15 to 11 kbar in garnet mica schists during normal-sense shearing. These data and the presence of decompression-related pegmatites dated at 434 Ma and 429 Ma indicate that the Seve nappes form a large-scale extrusion wedge. This wedge extends along strike for at least 150 km and marks an early stage of ultrahigh-pressure metamorphism, exhumation, and orogenic wedge formation in this part of the Scandinavian Caledonides predating the major, post–415 Ma ultrahigh-pressure exhumation processes in southwestern Norway. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.