U-PB SHRIMP ZIRCON DATING OF MESOPROTEROZOIC MAGMATIC ROCKS FROM THE SCOTTBURGH AREA, CENTRAL MZUMBE TERRANE, KWAZULU-NATAL, SOUTH AFRICA

Abstract

Research Article| September 01, 2010 U-PB SHRIMP ZIRCON DATING OF MESOPROTEROZOIC MAGMATIC ROCKS FROM THE SCOTTBURGH AREA, CENTRAL MZUMBE TERRANE, KWAZULU-NATAL, SOUTH AFRICA B.M. EGLINGTON; B.M. EGLINGTON University of Saskatchewan, Saskatoon, Canada, e-mail: bruce.eglington@usask.ca Search for other works by this author on: GSW Google Scholar R.J. THOMAS; R.J. THOMAS British Geological Survey, Keyworth, Notts, NG12 5GG, United Kingdom, e-mail: bthomas@bgs.ac.uk Search for other works by this author on: GSW Google Scholar R.A. ARMSTRONG R.A. ARMSTRONG Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia, e-mail: Richard.Armstrong@anu.edu.au Search for other works by this author on: GSW Google Scholar South African Journal of Geology (2010) 113 (2): 229–235. https://doi.org/10.2113/gssajg.113.2.229 Article history 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 B.M. EGLINGTON, R.J. THOMAS, R.A. ARMSTRONG; U-PB SHRIMP ZIRCON DATING OF MESOPROTEROZOIC MAGMATIC ROCKS FROM THE SCOTTBURGH AREA, CENTRAL MZUMBE TERRANE, KWAZULU-NATAL, SOUTH AFRICA. South African Journal of Geology 2010;; 113 (2): 229–235. doi: https://doi.org/10.2113/gssajg.113.2.229 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 SocietySouth African Journal of Geology Search Advanced Search Abstract New U-Pb zircon SHRIMP dates are presented for two critical meta-igneous rock units from the Scottburgh area, central Mzumbe Terrane, Natal Sector of the Namaqua-Natal Metamorphic Province (“Natal belt”). A sample of the oldest syntectonic granitic orthogneisses of the Mzumbe Terrane, the Mzimlilo Granite, gave a date of 1147 ± 8 Ma. This is interpreted to represent the crystallisation age and thus gives a reliable minimum estimate of the age of the first, collision-related tectono-metamorphic episode (D1) in the Mzumbe Terrane. The date is younger than the earliest foliation in the Tugela Terrane to the north, but is in accordance with previous Ar-Ar dating of shear zones in that terrane. This implies that the early fabrics in the Tugela Terrane were rejuvenated at this time. Magmatic zircons from melanorite of the Equeefa Suite provided a SHRIMP crystallisation date of 1083 ± 6 Ma. The Equeefa Suite comprises a large mafic-ultramafic body west of Scottburgh, associated with a swarm of deformed mafic (amphibolitic) dykes. The suite forms a valuable time marker, having been emplaced after D1 but during the early stages of the major, long-lived oblique sinistral shearing episode, which led to the final juxtaposition of the Mzumbe and Margate Terranes. This event has been dated between ca. 1.05 and 1.0 Ga from previous studies. The Equeefa date is thus consistent with the previous data and defines a period of possible crustal extension between the major tectono-thermal events. Both dates obtained provide important constraints on tectono-magmatic events in this part of the Natal belt and are consistent with previous data. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.