...N.A. Vafeas; L.C. Blignaut; K.S. Viljoen; P. Le Roux Abstract The Paleoproterozoic Kalahari Manganese Field is the largest known land-based manganese (Mn) deposit on Earth and comprises five erosional relics of the iron- and manganese-rich Hotazel Formation. A total of 19 manganese ore samples from...

...Volker Lueders; Jens Gutzmer; Nicolas J. Beukes Abstract Fluid inclusions in hematite and hausmannite from high-grade Wessels-type ore from the Kalahari manganese field were studied using infrared microscopy. The data obtained suggest that both minerals were deposited cogenetically, along...

...H. Tsikos; J. M. Moore Abstract The origin of the giant manganese deposits of the Kalahari manganese field has been highly contentious for many years. Proposed models cover a diverse spectrum of genetic processes, from large-scale epigenetic replacement mechanisms, to submarine volcanogenic...

...Harilaos Tsikos; John M. Moore Abstract New data are presented concerning the petrography and geochemistry of the Paleoproterozoic Hotazel iron-formation of the Kalahari manganese field, South Africa. Mineralogically and texturally, the Hotazel iron-formation is very similar to Paleoproterozoic...

...J. Gutzmer; N. J. Beukes Abstract Low-grade Mamatwan-type sedimentary manganese ore has been upgraded to high-grade Wessels-type ore in the Kalahari manganese field. The alteration appears to be of hydrothermal (metasomatie) origin closely related to zones of ferruginization (hematitization...

...Takashi Miyano; Nicolas J. Beukes Abstract Physicochemical environments for the formation of quartz-free manganese oxide ores from the Hotazel Formation of the Kalahari manganese field, northern Cape Province, South Africa, are discussed quantitatively on the basis of the phase relations...

..., Kalahari manganese field, South Africa. Both minerals occur as brown radiating groups or aggregates of acicular or prismatic crystals, with individual crystals up to 0.15 × 0.04 × 0.02 mm for taniajacoite and 1.3 × 0.2 × 0.2 mm for strontioruizite. Minerals associated with taniajacoite include sugilite...

...M.O. De Kock; B.F. Monareng; L. Blignaut; A.J.B. Smith; N.J. Beukes Abstract A diabase sill intersected in drill core GHEX-59 from the Avontuur deposit of the Kalahari Manganese Field of South Africa displays an 8 m thick paleosaprolitic weathering profile developed below the regional unconformity...

... zircon age of 1.25 Ga for a felsic tuff in red beds of the Mapedi Formation in the Kalahari manganese field. The new tuff age shows that the Mapedi red beds east of the thrust were deposited >650 m.y. after the Mapedi Formation to the west, and therefore they are part of a distinct Mesoproterozoic...

.... (1993a) with the empirical formula (K 0.65 Na 0.31 )(Na 1.79 Li 0.21 )(Mg 2.13 Mn 3+ 1.43 Fe 3+ 0.52 Li 0.91 )Si 8 O 22 (OH) 2 . X-ray crystal-structure refinements of four crystals taken from the holotype material (Wessels Mine, Kalahari Manganese Field, South Africa) showed that this amphibole...

...Gerald Giester; Christian L. Lengauer; Helmut Pristacz; Branko Rieck; Dan Topa; Karl-Ludwig Von Bezing Abstract Cairncrossite is a new phyllosilicate species found in manganese ore on dumps of the Wessels Mine, Kalahari Manganese Field, South Africa. Associated minerals are richterite, sugilite...

...B. Rieck; H. Pristacz; G. Giester Abstract A new silicate, colinowensite, BaCuSi 2 O 6 , has been found in the Wessels mine, Kalahari Manganese Field, South Africa. It is associated with effenbergerite, wesselsite, lavinskyite, scottyite, diegogattaite, as well as with pectolite, quartz, aegirine...

...M. KUNZMANN; J. GUTZMER; N.J. BEUKES; G.P. HALVERSON Abstract The Paleoproterozoic Mooidraai Formation is an up to 220 m thick succession of marine carbonate rocks that caps the Fe- and Mn-bearing Hotazel Formation in the Kalahari Manganese Field, South Africa. Although it occupies an important...

... This is a stunningly beautiful book, one that is also packed with valuable information about manganese metallogenesis, and modestly priced. It’s a great value. The volume is, in one sense, a second edition of The Manganese Adventure , which came out in 1997, but the focus is entirely on the Kalahari deposits...

... differ in their behaviour upon heating, which can be “normal” if they collapse to form a 9 Å phase or “anomalous” if they preserve their original basal spacing. The “anomalous” thermal behaviour of tobermorite 11 Å from N’Chwaning II mine (Kalahari Manganese Field, Republic of South Africa), which does...

...Cristian Biagioni; Elena Bonaccorsi; Stefano Merlino; Danilo Bersani; Claudia Forte Abstract X-ray diffraction studies of “tobermorite 10 Å”, obtained through heating of the “anomalous” tobermorite 11 Å from N’Chwaning II mine (Kalahari Manganese Field, RSA), show the widespread structural disorder...

...Harilaos Tsikos; Nicolas J. Beukes; John M. Moore; Chris Harris Abstract The Kalahari manganese field in the Northern Cape province, South Africa, is a world-class manganese resource (ca. 8 billion tons at 20–48% Mn). It occurs within the Hotazel Formation in the uppermost Paleoproterozoic (2.65...

...D. A. D. Evans; J. Gutzmer; N. J. Beukes; J. L. Kirschvink Abstract We report paleomagnetic data from samples spanning several grades of enrichment in the Kalahari manganese field, South Africa, in order to assess mineralogical aspects of the ore-forming stages, and also to date these stages...