Ordovician magmatism, deformation, and exhumation in the Caledonides of central Norway: An orphan of the Taconic orogeny?

Research Article| October 01, 2002 Ordovician magmatism, deformation, and exhumation in the Caledonides of central Norway: An orphan of the Taconic orogeny? Aaron S. Yoshinobu; Aaron S. Yoshinobu 1Department of Geosciences, Texas Tech University, Lubbock, Texas 79409, USA Search for other works by this author on: GSW Google Scholar Calvin G. Barnes; Calvin G. Barnes 1Department of Geosciences, Texas Tech University, Lubbock, Texas 79409, USA Search for other works by this author on: GSW Google Scholar Øystein Nordgulen; Øystein Nordgulen 2Norwegian Geological Survey, Leiv Eirikssons 39, 7491 Trondheim, Norway Search for other works by this author on: GSW Google Scholar Tore Prestvik; Tore Prestvik 3Department of Geology and Mineral Resources Engineering, Norwegian University of Science and Technology, N-7491 Trondheim, Norway Search for other works by this author on: GSW Google Scholar Mark Fanning; Mark Fanning 4Research School of Earth Sciences, Australian National University, Canberra ACT-0200, Australia Search for other works by this author on: GSW Google Scholar R.B. Pedersen R.B. Pedersen 5Geological Institute, University of Bergen, Allegaten 41, N-5007 Bergen, Norway Search for other works by this author on: GSW Google Scholar Geology (2002) 30 (10): 883–886. https://doi.org/10.1130/0091-7613(2002)030<0883:OMDAEI>2.0.CO;2 Article history received: 23 Mar 2002 rev-recd: 08 Jun 2002 accepted: 19 Jun 2002 first online: 02 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 Aaron S. Yoshinobu, Calvin G. Barnes, Øystein Nordgulen, Tore Prestvik, Mark Fanning, R.B. Pedersen; Ordovician magmatism, deformation, and exhumation in the Caledonides of central Norway: An orphan of the Taconic orogeny?. Geology 2002;; 30 (10): 883–886. doi: https://doi.org/10.1130/0091-7613(2002)030<0883:OMDAEI>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 Magmatism, contractional deformation, and extension associated with the exhumation of high-pressure rocks in the Scandinavian Caledonides are commonly attributed to the Silurian-Devonian Scandian orogeny, in which eastward thrusting of allochthonous terranes over Baltica was followed by extensional collapse and exhumation. New fieldwork and U-Pb geochronology coupled with recent pressure-temperature estimates within the highest thrust sequence of the Caledonian orogen indicate that an earlier phase of west-directed contractional deformation was punctuated by migmatite-producing events and voluminous magmatism ca. 477–466 Ma and ca. 447 Ma, followed by exhumation in the Late Ordovician. Al-in-hornblende and GASP thermobarometry indicate that emplacement of a suite of 448–445 Ma plutons caused partial migmatization at pressures of 700–800 MPa. Subsequent isothermal exhumation to pressures of 400 MPa occurred while the host rocks were still partially molten. Rates of exhumation may have ranged from 2 to 11 mm·yr−1 or greater. These data provide evidence for a previously unrecognized phase of exhumation in the Caledonides and for aerially extensive west-vergent deformation. Deformation and magmatism associated with these events may be related to Taconic-age orogenesis near Laurentia, where the highest nappe sequences of the Scandinavian Caledonides probably resided during early Paleozoic time. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.