Folding of the Rustenburg layered suite adjacent to the Steelpoort pericline: implications for syn-Bushveld tectonism in the eastern Bushveld Complex

Abstract

Research Article| September 01, 2005 Folding of the Rustenburg layered suite adjacent to the Steelpoort pericline: implications for syn-Bushveld tectonism in the eastern Bushveld Complex Brendan M. Clarke; Brendan M. Clarke KwaZulu-Natal Unit, Council for Geoscience, P.O. Box 900, Pietermaritzburg, 3200, South Africa, School of Geological Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa, e-mail: bmclarke@mweb.co.za Search for other works by this author on: GSW Google Scholar Ron Uken; Ron Uken School of Geological Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa, e-mail: uken@ukzn.ac.za; watkeys@ukzn.ac.za; reinhardtj@ukzn.ac.za Search for other works by this author on: GSW Google Scholar Mike K. Watkeys; Mike K. Watkeys School of Geological Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa, e-mail: uken@ukzn.ac.za; watkeys@ukzn.ac.za; reinhardtj@ukzn.ac.za Search for other works by this author on: GSW Google Scholar Jürgen Reinhardt Jürgen Reinhardt School of Geological Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa, e-mail: uken@ukzn.ac.za; watkeys@ukzn.ac.za; reinhardtj@ukzn.ac.za Search for other works by this author on: GSW Google Scholar Author and Article Information Brendan M. Clarke KwaZulu-Natal Unit, Council for Geoscience, P.O. Box 900, Pietermaritzburg, 3200, South Africa, School of Geological Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa, e-mail: bmclarke@mweb.co.za Ron Uken School of Geological Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa, e-mail: uken@ukzn.ac.za; watkeys@ukzn.ac.za; reinhardtj@ukzn.ac.za Mike K. Watkeys School of Geological Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa, e-mail: uken@ukzn.ac.za; watkeys@ukzn.ac.za; reinhardtj@ukzn.ac.za Jürgen Reinhardt School of Geological Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa, e-mail: uken@ukzn.ac.za; watkeys@ukzn.ac.za; reinhardtj@ukzn.ac.za Publisher: Geological Society of South Africa First Online: 09 Mar 2017 Online ISSN: 1996-8590 Print ISSN: 1012-0750 © 2005 Geological Society of South Africa South African Journal of Geology (2005) 108 (3): 397–412. https://doi.org/10.2113/108.3.397 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 Brendan M. Clarke, Ron Uken, Mike K. Watkeys, Jürgen Reinhardt; Folding of the Rustenburg layered suite adjacent to the Steelpoort pericline: implications for syn-Bushveld tectonism in the eastern Bushveld Complex. South African Journal of Geology 2005;; 108 (3): 397–412. doi: https://doi.org/10.2113/108.3.397 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 The northeastern Bushveld Complex contact aureole is characterised by numerous, subequally-spaced, kilometre-scale metasedimentary Pretoria Group floor rock domes that penetrate the overlying Rustenburg Layered Suite to varying stratigraphic levels. The origin of these floor domes has been the subject of much debate, with both regional folding and diapiric models invoked as causal processes. Of late, however, the diapiric model of deformation has gained support and has been successfully thermomechanically modelled. Here the Rustenburg Layered Suite adjacent to one of these floor domes, the Steelpoort pericline, is examined and high-strain zones in the magmatic rocks in close spatial proximity to the pericline are described. On the northeastern flank of the pericline, the lower part of the Rustenburg Layered Suite is gently folded but discordant to the floor rock structure against which it abuts. The folds are characterised by their curvilinear axial traces that are parallel to the contact between the metasediments of the floor dome and the encircling igneous rocks. On the southwestern flank, high strain shear zones, characterised by sheath folds and strong tectonic fabrics, indicate shedding of igneous material off the flanks of the dome. These deformation zones adjacent to the Steelpoort pericline add independent support to the diapiric model of deformation proposed for the domal structures. The folding on the northeastern flank is readily attributable to diapir-induced drag and compression associated with diapiric growth. The sheath folds on the southwestern flank formed by the gravity-induced shedding of partially crystallised igneous material off the dome flanks during diapiric uplift. In addition, the numerous transgressive and onlapping relationships observed between units of the Rustenburg Layered Suite adjacent to the floor domes is compatible with diapiric deformation of the floor rocks. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.