Research Article| July 01, 2008 Ghosts of lithospheres past: Imaging an evolving lithospheric mantle in southern Africa Alan F. Kobussen; Alan F. Kobussen 1Geochemical Evolution and Metallogeny of Continents, Australian Research Council National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, Sydney, NSW 2109, Australia Search for other works by this author on: GSW Google Scholar William L. Griffin; William L. Griffin 1Geochemical Evolution and Metallogeny of Continents, Australian Research Council National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, Sydney, NSW 2109, Australia Search for other works by this author on: GSW Google Scholar Suzanne Y. O'Reilly; Suzanne Y. O'Reilly 1Geochemical Evolution and Metallogeny of Continents, Australian Research Council National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, Sydney, NSW 2109, Australia Search for other works by this author on: GSW Google Scholar Simon R. Shee Simon R. Shee 2Shee & Associates Pty. Ltd., Glen Iris, VIC 3146, Australia Search for other works by this author on: GSW Google Scholar Geology (2008) 36 (7): 515–518. https://doi.org/10.1130/G24868A.1 Article history rev-recd: 14 Feb 2008 accepted: 04 Mar 2008 received: 06 Aug 2008 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Alan F. Kobussen, William L. Griffin, Suzanne Y. O'Reilly, Simon R. Shee; Ghosts of lithospheres past: Imaging an evolving lithospheric mantle in southern Africa. Geology 2008;; 36 (7): 515–518. doi: https://doi.org/10.1130/G24868A.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 SocietyGeology Search Advanced Search Abstract Group II (143–117 Ma) and Group I kimberlites (108–74 Ma) intrude across the southwest boundary of the Kaapvaal craton, sampling the same volume of the subcontinental lithospheric mantle (SCLM) in two time slices. Major and trace element analyses of 3699 peridotitic garnet xenocrysts were used to construct paleogeotherms for 17 kimberlite localities, and to place each garnet at its depth of origin. The Ti contents of each garnet and the calculated XMg of its coexisting olivine were projected onto a southwest-northeast section across the craton boundary, and splines were used to interpolate between the virtual boreholes in each age group. The sections show that the cratonic SCLM extends at least 75 km southwest of the mapped craton boundary, suggesting a dipping contact. Marked differences between the time-slice sections show that between 117 and 108 Ma the SCLM on both sides of the craton boundary was heated and chemically refertilized by infiltrating asthenosphere-derived melts, thinning the depleted layer by ~40 km. The thermal and geochemical changes record a significant tectonothermal event that may be related to changes in the stress field associated with opening of the South Atlantic, or with mantle upwelling. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.