stripes
Apart from Semarule (024-00-001) there are elsewhere within the Gaborone granite facies that are peralkaline, although the distribution of these rocks is not well known. The Kgale granite, for instance, particularly near its margins and in certain granophyric facies, contains aegirine-augite and riebeckite (Grobler, 1996). A group of peralkaline rhyolites forms part of the Kanye Formation which is distributed as a linear belt some 150 km long around the eastern and southern margins of the Gaborone granite. Smaller areas occur southwest and south of the granite. Some of these rhyolites contain aegirine. A small part of the Gaborone granite and part of the Kanye Formation, including the Vlakpan structure immediately to the north of Mafikeng, lie within South Africa. A general account of the distribution of these peralkaline rocks is given by Grobler (1996).
GROBLER, D.F. 1996. The geology, geochemistry and geochronology of the Gaborone granite suite and Kanye Formation north of Mafikeng, South Africa. PhD thesis, University of Witwatersrand, Johannesburg. 457 pp. (unpublished)
** GROBLER, D.F. & WALRAVEN, F. 1993. Geochronology of Gaborone Granite Complex extensions in the are north of Mafikeng, South Africa. Chemical Geology, 105, 4, 319-337 doi.org/10.1016/0009-2541(93)90134-5
** MOORE, M., DAVIS, D.W., ROBB, L.J., JACKSON, M.C., GROBLER, D.F. Archean Rapakivi granite-anorthosite-rhyolite complex in the Witwatersrand basin hinterland, southern Africa. Geology, 21, 11, 1031-1034, doi.org/10.1130/0091-7613(1993)021%3C1031:ARGARC%3E2.3.CO;2