Magnetic anomaly near the center of the Vredefort structure: Implications for impact-related magnetic signatures

Research Article| March 01, 1995 Magnetic anomaly near the center of the Vredefort structure: Implications for impact-related magnetic signatures Rodger J. Hart; Rodger J. Hart 1Schonland Research Centre, University of the Witwatersrand, P.O. Box 3, Wits 2050, Johannesburg, South Africa Search for other works by this author on: GSW Google Scholar Robert B. Hargraves; Robert B. Hargraves 2Department of Geological and Geophysical Sciences, Princeton University, Princeton, New Jersey 08540 Search for other works by this author on: GSW Google Scholar Marco A. G. Andreoli; Marco A. G. Andreoli 3Atomic Energy Corporation of South Africa Ltd., P.O. Box 582, Pretoria, 0001, South Africa Search for other works by this author on: GSW Google Scholar Marian Tredoux; Marian Tredoux 4Department of Geological Sciences, University of Cape Town, Rondebosch 7700, South Africa Search for other works by this author on: GSW Google Scholar C. Moctar Doucouré C. Moctar Doucouré 5Bernard Price Institute for Geophysics, University of the Witwatersrand, P.O. Box 3, Wits 2050, Johannesburg, South Africa Search for other works by this author on: GSW Google Scholar Geology (1995) 23 (3): 277–280. https://doi.org/10.1130/0091-7613(1995)023<0277:MANTCO>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 Rodger J. Hart, Robert B. Hargraves, Marco A. G. Andreoli, Marian Tredoux, C. Moctar Doucouré; Magnetic anomaly near the center of the Vredefort structure: Implications for impact-related magnetic signatures. Geology 1995;; 23 (3): 277–280. doi: https://doi.org/10.1130/0091-7613(1995)023<0277:MANTCO>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 A strong magnetic anomaly near the center of the ancient and deeply eroded Vredefort structure is attributed to remanent magnetization caused by a large meteorite impact at ∼2.0 Ga. The rocks underlying the anomaly are Archean gneisses thought to represent mid-crustal depths that were uplifted to the surface during the postulated impact event. Measurements of the remanent magnetization of the basement rocks yielded consistent vectors of declination = 25° , inclination = 56° , k = 18, α = 16 that correspond to the paleomagnetic pole position at time of impact. Petrologic studies indicate that during impact, large volumes of rock were heated enough to cause thermal remagnetization in the ambient field. Thermal effects of all large impacts on cratons may induce a remanent magnetization of sufficient intensity to cause anomalies in the geomagnetic field that are detectable even by satellites. 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.