Conglomerates uranium

Quartz crystals, growth of, 14 93, 94 Quartz-pebble conglomerate uranium deposits, 17 520... 

Quartz-pebble (Oligomictic) conglomerate uranium deposits... 

Thorium is widely but rather sparsely distributed and its only commercial sources are monazite sands (see p. 1229) and the mineral conglomerates of Ontario. The former are found in India, South Africa, Brazil, Australia and Malaysia, and in exceptional cases may contain up to 20% Th02 but more usually contain less than 10%. In the Canadian ores the thorium is present as uranothorite, a mixed Th,U silicate, which is accompanied by pitchblende. Even though present as only 0.4% Th02, the recovery of Th, as a co-product of the recovery of uranium, is viable. 

The fossil placer deposits are in fact gold-bearing conglomerates that carry small amounts of PGM, together with gold, uranium and other heavy minerals. However, studies conducted revealed that some of the fossil placer deposits contain about 22 PGM species, including Ir-Os-Ru alloys, sperrylite and isoferroplatinum. 

Uranium mineralization in the Windsor area is a typical sandstone roll-front type. The Green Street occurrence that is the focus of this study occurs in thick arkosic sandstones, siltstones, and pebbly conglomerates of the Cheverie Formation (Fig. 2). The occurrence is a remnant tail of a uranium roll front that has subsequently migrated down dip from the outcropping (Ryan O Beirne-Ryan 2007). 

Pyritic, uranium-bearing, quartz-pebble conglomerates have been found in Canada, in South Africa, in Brazil and in western Australia. The conglomerates are all of similar aspect and the minerals of interest are of similar character. 

Sedinientary rocks that contain potassium, as well as uranium and thorium and their respective radioactive daughters emit ganuna rays as the unstable atoms of these elements decay (Faure and Mensing 2005). Uranium and thorium occur in the heavy minerals that are included in sandstones and conglomerates at the time of deposition. In addition, uranium (but not thorium) may be deposited from groundwater in case the sediment contains organic matter that can reduce hexavalent uranyl ions to the tetravalent state... 

Paleo-placers Conglomerates of quartzite and mica in precambrian sedimentary rocks. May contain gold, silver, platinum and uranium The biggest gold producer in the world, Witivatersrand in South Africa has several mines with this ore type... 

Brannerite is the third most important reduced uranium mineral in that it occurs in many different types of deposits and is the chief uranium producer in the conglomerates of Blind River-Elliot Lake, Ontario, Canada. Although it has been found in pegmatites, hydrothermal and sedimentary deposits, it is always associated with uraninite and probably forms through reactions with uraninite and titanium phases that are also present. 

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