The extent of juvenile crust in the Grenville Province: Nd isotope evidence

Abstract

Research Article| May 01, 2010 The extent of juvenile crust in the Grenville Province: Nd isotope evidence A.P. Dickin; A.P. Dickin † School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario L8S 4M1, Canada †E-mail: dickin@mcmaster.ca Search for other works by this author on: GSW Google Scholar R.H. McNutt; R.H. McNutt School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario L8S 4M1, Canada Search for other works by this author on: GSW Google Scholar C. Martin; C. Martin School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario L8S 4M1, Canada Search for other works by this author on: GSW Google Scholar A. Guo A. Guo * School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario L8S 4M1, Canada *Present address: State Key Laboratory of Continental Dynamics and Department of Geology, Northwest University, Xian 710069, China Search for other works by this author on: GSW Google Scholar Author and Article Information A.P. Dickin † School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario L8S 4M1, Canada R.H. McNutt School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario L8S 4M1, Canada C. Martin School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario L8S 4M1, Canada A. Guo * School of Geography and Earth Sciences, McMaster University, Hamilton, Ontario L8S 4M1, Canada †E-mail: dickin@mcmaster.ca *Present address: State Key Laboratory of Continental Dynamics and Department of Geology, Northwest University, Xian 710069, China Publisher: Geological Society of America Received: 02 Dec 2007 Revision Received: 04 May 2009 Accepted: 28 May 2009 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2010 Geological Society of America GSA Bulletin (2010) 122 (5-6): 870–883. https://doi.org/10.1130/B26381.1 Article history Received: 02 Dec 2007 Revision Received: 04 May 2009 Accepted: 28 May 2009 First Online: 08 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 A.P. Dickin, R.H. McNutt, C. Martin, A. Guo; The extent of juvenile crust in the Grenville Province: Nd isotope evidence. GSA Bulletin 2010;; 122 (5-6): 870–883. doi: https://doi.org/10.1130/B26381.1 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 SocietyGSA Bulletin Search Advanced Search Abstract A large Nd isotope data set is presented to generate a crustal formation age map for the southwest Grenville Province, placing it in the context of the province as a whole. Previous studies have shown that most crust in the central and eastern parts of the province is pre-Grenvillian, composed largely of juvenile 1.5, 1.7, 1.9, and 2.7 Ga arc terranes, partly reworked by later ensialic arcs and collision zones. In contrast, new Nd data reported here show that juvenile monocyclic crust is restricted to the SW Grenville Province, in part of the Central Metasedimentary Belt interpreted as a failed backarc rift zone. There is a clear isotopic distinction between this rift zone and the pre-Grenvillian crust on the flanks. On the flanks of the rift zone, there is evidence for two crust-forming events, comprising an earlier (1.5 Ga) juvenile Pinwarian event, and a later 1.4–1.3 Ga continental margin arc (the Elzevirian Orogeny). Based on the geographical distribution of Nd model ages in the SW Grenville Province, a revised tectonic model for the Grenville Orogeny is developed. In this model, backarc spreading created a rift zone behind a (pre-Grenvillian) Elzevirian subduction zone that obliquely straddled the edge of a Mesoproterozoic continental margin. As a result of this geometry, the rift zone died out to the north as it propagated into cold Archean crust. Elzevirian subduction was probably halted by the collision of the continental margin with an offshore arc, and later with a major continental block, giving rise respectively to the Shawinigan and the Ottawan orogenic events. These collisional events can be grouped as parts of the Grenville Orogenic Cycle. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.