Tectonic setting and terrane accretion of the Archean Zimbabwe craton

Research Article| February 01, 1998 Tectonic setting and terrane accretion of the Archean Zimbabwe craton T. M. Kusky T. M. Kusky 1Department of Earth Sciences, Boston University, Boston, Massachusetts 02215 Search for other works by this author on: GSW Google Scholar Geology (1998) 26 (2): 163–166. https://doi.org/10.1130/0091-7613(1998)026<0163:TSATAO>2.3.CO;2 Article history 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 T. M. Kusky; Tectonic setting and terrane accretion of the Archean Zimbabwe craton. Geology 1998;; 26 (2): 163–166. doi: https://doi.org/10.1130/0091-7613(1998)026<0163:TSATAO>2.3.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 The Archean Zimbabwe craton is made of a number of distinct tectonostratigraphic terranes assembled by plate tectonic processes. The central Tokwe terrane consists of 3.5–2.95 Ga gneissic rocks and structurally complex inliers of possibly older greenstone belts. These are overlain unconformably by a 2.9–2.8 Ga assemblage of mafic and felsic volcanic rocks and conglomerates, and a separate 3.0–2.7 Ga southeastward thickening platform sequence of sandstone, shale, and limestone. 2.7 Ga greenstone belts form two distinctly different domains flanking the central terrane. Northwest of the ancient gneissic terrane, ca. 2.7 Ga greenstone belts comprise a series of calc-alkaline lavas and intercalated sedimentary rocks intruded by syn-volcanic plutons. Southeast of the ancient gneissic complex, 2.7 Ga greenstone belts consist of thick piles of tholeiitic basalts overlying ultramafic lavas, resting allochthonously over the shallow-water platform sequence and older gneissic terrane. This division of the Zimbabwe craton is interpreted to show that the central Tokwe terrane had a continental magmatic arc built on its northwestern edge, as its southeastern margin rifted from another fragment, forming the Sea of Umtali. A passive-margin sedimentary wedge formed on the rifted southeastern edge of this ancient continent, and prograded onto the craton during sedimentary and tectonic loading of the craton margin. The southeastern greenstone belts formed as thick oceanic crust (oceanic plateau) in this back-arc basin, and were later obducted on to the rift and passive margin sequence as the Sea of Umtali closed ca. 2.7 Ga. This was followed by intrusion of granitic plutons of the Chilimanzi suite ca. 2.6 Ga in a tectonic regime of intracontinental strike-slip faulting, representing a response to the Zimbabwe-Kaapvaal continent-continent collision. Crustal and lithospheric thickening during intrusion of these late granites may have played a role in stabilizing the Zimbabwe craton and forming the lithospheric root. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.