...A.R. CABRAL; J.M. MOORE† Abstract Otjosondu, a Neoproterozoic ferromanganese deposit located about 130 km north-east of Okahandja, Namibia, has a garnet-braunite-barite rock containing ~32 weight % barium. The garnet is intergrown with barite and has end-member proportions as follows: spessartine...

...A.R. CABRAL; J.M. MOORE; B.S. MAPANI; M. KOUBOVÁ; C.-D. SATTLER Abstract The stratigraphic position of the Otjosondu ferromanganese deposit in the Neoproterozoic Damara Supergroup in the Central Zone of the Pan-African Damara orogenic belt is uncertain. Comparison of the enclosing host rocks...

...Bernhard Buehn; Ian G. Stanistreet; Martin Okrusch Abstract The Otjosondu manganese mining area is located at the eastern exposed extent of the inland branch of the late Proterozoic Damara orogen. In spite of intense deformation and a high-grade metamorphic overprint, the sedimentological...

... and mineral compositions--mainly in jacobsites and garnets.The Koduru and Garbham deposits have remarkable mineralogical similarities with gonditic deposits in northern India and other stratified metasedimentary manganese deposits, such as the Otjosondu (S. W. Africa) and Franklin (U. S. A.) deposits...

... under the acronym “spandite” in old literature. Occurrences of spessartine-andradite have been described from high-pressure Fe-Mn-rich metasedimentary rocks in India (Katkamsandi, Netra), Namibia (Otjosondu, Gamsberg, Namaqualend), Greece (Andros Island), an iron formation in Canada (Wabush...

... contain complex intergrowths K-feldspar, albite and hyalophane. Barian assemblages were identified in four of the 80 Grenville marbles investigated by Rathmell (1993) . The Grenville rocks in this area of southern Ontario were metamorphosed around 1.17 Ga ago subsequent to deposition on a continental...

... of black shale deposits – a summary report . Economic Geology , 65 , 253 – 272 . Viswanathan , K. ( 1978 ) Intergrowth of Ba-rich and Bapoor phases in barium feldspar from Otjosondu, South-West Africa . Mineralogical Magazine , 42 , 294 . Viswanathan , K. and Kielhorn , H.-M...

... and iron deposits at Otjosondu (Namibia) related to Damara oceanic opening . Economic Geology , 87 , 1393 – 1411 . Burger , A.J. , Clifford , T.N. and Miller , R.McG. ( 1976 ). U-Pb ages of the Fransfontein granitic suite, northern South West Africa . Precambrian Research , 12...

...F ig . 1. Deposits mentioned in text: (1) Adilabad, (2) Cuyuna IF, (3) Groote Eylandt, (4) Jiaodingshan, (5) Kalahari, (6) Molango, (7) Nikopol’, (8) Noda-Tamagawa, (9) Nsuta, (10) Otjosondu, (11) Taojiang, Tanganshan, (12) Tiantaishan, (13) Urkút, (14) Urucum, (15) Usa, (16) Wafangzi. Size...

... Wales. Jour. Geol. Soc. Aust., v. 15, pp. 1-8. roE VILLIERS, J, E., (1951) The manganese ores of Otjosondu, S.W. Africa. Trans. Geol. Soc. South Africa, v. 54, pp. 89-98. IDoRR, 1. V. N., COELHO, 1. S. and HOREN, A., (1956) The manganese deposits of Minas Gerais, Brazil. 20th Int. Geol. Congress...

...Marcel Stalder; Abraham Rozendaal Abstract Calderite-rich garnet and franklinite–jacobsite-rich spinel occur in amphibolite-facies hydrothermal metasedimentary rocks that stratigraphically overlie the Proterozoic Gamsberg Zn–Pb deposit, South Africa. The minerals are restricted in occurrence...

... of the Mineralogical Society of America (see inside front cover of recent issue) for price information. Deposit items may also be available on the American Mineralogist web site ( http://www.minsocam.org or current web address). Chemical analyses were performed on a Cameca CAMEBAX 355 electron-microprobe system...

...-grained cryolite. Specimen size is 4.5 × 2 × 1.7 cm. From the type locality, Ivigtut Cryolite deposit, Ivittuut (Ivigtut), Kitaa, Greenland. Pavel M. Kartashov collection and photograph. ( c ) Grossular, end-member formula {Ca 3 }[Al 2 ](Si 3 )O 12 : a trapezohedron {211}, 3.5 cm across on the left...

... sediment, as observed in sedimentary cycles of the Paleoproterozoic Hotazel Formation (Mhlanga et al., 2023) and the Neoproterozoic Otjosondu Mn and Fe deposits in Namibia (Beukes et al., 2016). The second depositional scenario utilises the same redox relationship between Mn and Fe as described...

... Proterozoic outer shelf manganese and iron deposits of Otjosondu (Namibia) related to the Damara oceanic opening . Economic Geology , 87 , 1393 - 1411 . Buick , R. , Des Marais D.J. and Knoll , A.H. 1995 . Stable isotopic compositions of carbonates from the Mesoproterozoic Bangemall...

... that the occurrence of the SJ anomaly as a major uranium deposit is linked to the high H 2 O and total fluid contents. This study illustrates the usefulness of this technique to distinguish between economic mineralization and the sub-economic SH anomaly. © 2002 AAG/The Geological Society of London 2002 fluid...

... are typically associated with manganese–ferromanganese deposits (Viswanathan and Kielhorn, 1983 ; McSwiggen et al. , 1994 ), stratabound Ba-rich sulfide deposits (Fortey and Beddoe–Stephens, 1982 ; Chabu and Boulègue, 1992 ), baryte deposits (Moro et al. , 2001 ; Xia et al. , 2005 ; Han et al. , 2013...