Asbestiform manjiroite and todorokite from the Kalahari manganese field, South Africa

Research Article| December 01, 2000 Asbestiform manjiroite and todorokite from the Kalahari manganese field, South Africa J. Gutzmer; J. Gutzmer Department of Geology, Rand Afrikaans University, P.O. Box 524, Auckland Park 2006, South Africa, e-mail: jg@na.rau.ac.za; njb@na.rau.ac.xa Search for other works by this author on: GSW Google Scholar Nicolas J. Beukes Nicolas J. Beukes Department of Geology, Rand Afrikaans University, P.O. Box 524, Auckland Park 2006, South Africa, e-mail: jg@na.rau.ac.za; njb@na.rau.ac.xa Search for other works by this author on: GSW Google Scholar Author and Article Information J. Gutzmer Department of Geology, Rand Afrikaans University, P.O. Box 524, Auckland Park 2006, South Africa, e-mail: jg@na.rau.ac.za; njb@na.rau.ac.xa Nicolas J. Beukes Department of Geology, Rand Afrikaans University, P.O. Box 524, Auckland Park 2006, South Africa, e-mail: jg@na.rau.ac.za; njb@na.rau.ac.xa Publisher: Geological Society of South Africa First Online: 07 Mar 2017 Online ISSN: 1996-8590 Print ISSN: 1012-0750 © 2000 Geological Society of South Africa South African Journal of Geology (2000) 103 (3-4): 163–174. https://doi.org/10.2113/1030163 Article history First Online: 07 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation J. Gutzmer, Nicolas J. Beukes; Asbestiform manjiroite and todorokite from the Kalahari manganese field, South Africa. South African Journal of Geology 2000;; 103 (3-4): 163–174. doi: https://doi.org/10.2113/1030163 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 Asbestiform manjiroite and todorokite occur as infill of bedding parallel extension veinlets in supergene altered braunite-kutnahorite lutite at the Smartt Mine in the Kalahari manganese field, South Africa. Geological evidence and preliminary geochronological studies suggest that hydraulic extension and formation of the asbestiform Mn oxihydroxides took place during Tertiary uplift and tilting of the South African Subcontinent. Careful chemical studies of both minerals confirm the role of Mg as a minor but essential constituent in the todorokite structure that is located on a distinct – but as yet undetermined – crystallographic site within the tunnels of the todorokite framework structure. This site is distinct from the one occupied by large cations such as Ca, Na and K. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.