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Quartz-pebble conglomerate deposits

Quartz-Pebble Conglomerate Deposits. Known quartz-pebble conglomerate ores are restricted to a specific period of geologic time. These ore types occur in basal Lower Proterozoic beds unconformably situated above Archaean basement rocks composed of granitic and metamorphic strata. A number of commercial deposits are located in Canada and South Africa. Some subeconomic occurrences have been reported in Brazil and India... [Pg.184]

Quartz-pebble conglomerate Commercial deposits are available in Canada and South Africa, and... [Pg.73]

Quartz crystals, growth of, 14 93, 94 Quartz-pebble conglomerate uranium deposits, 17 520... [Pg.780]

Cyclical deposits of sandstone, shale and coal. Each cycle starts with a massive sandstone bed featuring large-scale trough cross-bedding and shale clasts at the base. Fossil leaves of Glossopteris and petrified tree trunks up to 60 cm in diameter are common, many are still upright. A quartz-pebble conglomerate occurs at the base of this formation Disconformity... [Pg.317]

The Queen Maud Formation is a coarse grained conglomeratic sandstone that lies unconformably on the rocks of the Weaver Formation. This unit is about 25 m thick and is equivalent to the basal quartz-pebble conglomerate of the Queen Maud Formation on Mt. Weaver. On Tillite Ridge in the Wisconsin Range the Queen Maud Formation is overlain by indurated till more than 30 m thick. This till is probably of Pleistocene or even of Pliocene age and thus is one of the many late Cenozoic glacial deposits in theTransantarctic Mountains that are collectively included in the Sirius Group. [Pg.319]

Palaeo-placer U,Ti,Au,Zr,C,S Pyritic quartz-pebble conglomerate in fluvial channel deposits, uraninite-brannerite as matrix grains age, restriction 2900-2200 m.y. Elliot Lake, Canada Witwatersrand, R.S.A. [Pg.90]

Early Proterozoic time was characterized throughout the world by the initial deposition of layered supracrustal sequences composed predominantly of basal subaerial quartz-pebble conglomerate, shallow to deep water marine carbonate and clastic sedimentary rocks, iron formation and mafic volcanic or intrusive rocks. The depositional environments ranged from subaerial (fluvial) to marine, and the pre-depositional land surface was extensively peneplaned and chemically weathered,... [Pg.91]

The bulk of the world s uranium has been produced historically from (1) lower Proterozoic uraninite placer deposits in quartz-pebble conglomerates, (2) epigenetic uranium deposits in sandstones located in many cases at, or near, groundwater oxidation-reduction interfaces and (3) hydrothermal vein uranium deposits. These three distinctly different geologic environments provided most of the uranium that was produced from the 1940s to the early 1970s and they continue to be important exploration targets in the search for new uranium deposits. [Pg.102]

Classic quartz-pebble conglomerate districts are the Blind River-Elliot Lake district, Canada, and the Witwatersrand, South Africa. Similar deposits are known in Australia, Brazil, Finland, Algeria, India, the U.S.S.R. and the U.S.A. [Pg.119]

Quartz-pebble (Oligomictic) conglomerate uranium deposits... [Pg.117]

See other pages where Quartz-pebble conglomerate deposits is mentioned: [Pg.314]    [Pg.322]    [Pg.23]    [Pg.96]    [Pg.314]    [Pg.322]    [Pg.23]    [Pg.96]    [Pg.74]    [Pg.499]    [Pg.366]    [Pg.496]    [Pg.497]    [Pg.121]    [Pg.7]    [Pg.92]    [Pg.92]    [Pg.106]    [Pg.119]    [Pg.120]    [Pg.128]    [Pg.2]    [Pg.313]    [Pg.313]    [Pg.297]    [Pg.118]    [Pg.191]    [Pg.124]   
See also in sourсe #XX -- [ Pg.322 ]



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Quartz-pebble conglomerates, uranium deposits

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