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1 edition of Geochemical aspects of the origin of detrital pyrite in Witwatersrand conglomerates. found in the catalog.

Geochemical aspects of the origin of detrital pyrite in Witwatersrand conglomerates.

Geochemical aspects of the origin of detrital pyrite in Witwatersrand conglomerates.

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Published by University of the Witwatersrand in Johannesburg .
Written in English

    Subjects:
  • Witwatersrand

  • Edition Notes

    11

    The Physical Object
    Pagination21 p.
    Number of Pages21
    ID Numbers
    Open LibraryOL22016508M

      OCLC Number: Description: approximately pages in various pagings: illustrations ; 29 cm: Contents: Frontispiece --Introduction / Frank C. Armstrong --History: A. Investigation of Witwatersrand uranium-bearing quartz-pebble conglomerates in / Weston Bourret --General: Precambrian development of an oxygenic atmosphere / J. William Schopf --C. .   Petrographic and sulphur isotope studies support the long‐held contention that rounded grains of pyrite in siliciclastic sequences of the Late Archaean Witwatersrand Supergroup originated as placer grains.

    Search the history of over billion web pages on the Internet. search Search the Wayback Machine. Featured texts All Books All Texts latest This Just In Full text of "The banket, a study of the auriferous conglomerates of the Witwatersrand and the associated rocks". Basin of South Africa, the world’s largest gold deposit. According to these authors, detrital pyrite is mainly derived from sedimentary sources and syn-sedimentary precipitates. Young has discussed the ice ages in earth history,“puzzling” paleolatitudes, and regional provenance of the ice sheets.

    S-isotope data from pyrite in the Boundary Ridge diamictites analyzed in this study and previous work (Williford et al., ) define multiple δ34S vs. δ33S arrays, linked to a source of detrital pyrite from the overlying Hamersley and Fortescue groups. However, the Precambrian quartz-pebble conglomerates of Colorado do not contain the key indicator minerals of primary detrital pyrite, uraninite, and other uranium mineral species. The absence of these minerals and the structural and stratigraphic relations of these two formations suggest that more» they were deposited between and


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Geochemical aspects of the origin of detrital pyrite in Witwatersrand conglomerates Download PDF EPUB FB2

Detrital pyrite is an accessory mineral in clastic sedimentary rocks deposited prior to c. It is a redox-sensitive mineral and an indicator of low oxygen levels prior to the rise of atmospheric oxygen in the early by: 1. This hypothesis arose from combining the widely held beliefs that the gold grains in the Witwatersrand conglomerates were detrital in origin, and that round uraninite and pyrite grains spatially associated with the gold probably had a similar origin.

Detrital pyrite is an accessory mineral in clastic sedimentary rocks deposited prior to c. It is a redox-sensitive mineral and an indicator of low oxygen levels prior to the rise of. Apart from gold, associated mineral phases that are key to any plausible interpretation of the Witwatersrand deposits are pyrite and uraninite.

Between andup to million tons (Mt) of U 3 O 8 were produced from Witwatersrand quartz pebble conglomerates at an average grade of ppm U 3 O 8. Iron oxides are conspicuously lacking. Pyrite is the most abundant ore mineral in gold-bearing quartz pebble conglomerates (QPCs) of the Witwatersrand Basin and similar Archaean sedimentary units.

Much of the pyrite in Archaean conglomerates is detrital in origin, implying that it survived weathering, transport, and reworking under anoxic by: 1. Geochemical Aspects of the Origin of Detrital Pyrite in Witwatersrand Conglomerates October,21pp.

Information Circular No. Womackand and A. Button. Bibliography and Subject-Index of Brazilian Geology (Languages Other Than Portuguese) October,33pp. Information Circular No. Button. • rounded pyrites are detrital in origin • Cheshire pyrites are derived from Manjeri massive sulphides • Witwatersrand pyrites have mixed provenance – some are igneous/ high-T hydrothermal (e.g.

Dominion Reef) • lack of NMDF signal, near crustal δ56Fe values (±‰) – most are sedimentary in origin. Köppel VH, Saager R () Lead isotope evidence on the detrital origin of Witwatersrand pyrites and its bearing on the provenance of the Witwatersrand gold. Econ Geol – Google Scholar Kositcin N, Krapez B () SHRIMP U-Pb detrital zircon geochronology of the Late Archaean Witwatersrand Basin of South Africa: relation between.

Minter WEL () Irrefutable detrital origin of Witwatersrand gold and evidence of eolian signatures. Econ Geol – CrossRef Google Scholar Minter WEL, Feather CE, Glathaar CW () Sedimentological and mineralogical aspects of the newly discovered Witwatersrand placer deposit that reflect Proterozoic weathering, Welkom gold field.

the Witwatersrand deposits in his book Les Richesses Minérales de l’Afrique, with some alterations to take into account more recent developments. In the hundred years since De Launay succinctly and objectively outlined the main theories for the origin of Witwatersrand gold, two rival positions have become entrenched - the Modified.

Goal: This project is divided into 4 aspects. The first aspect is on the geological, geochemical and geophysical characteristics of gold-bearing Black Reef deposit in the Carletonville goldfield. These structures are preserved in some of the minute detrital pyrite grains of the Elsburg A1 and A3 horizons occurring near the top of the Witwatersrand system, the deposition of which is.

Reddy & Hough Microstructural evolution of Witwatersrand Manuscript - 1 - Microstructural evolution and trace element mobility in Witwatersrand pyrite Steven M. Reddy1* & Robert M. Hough2 19 1The Institute for Geoscience Research and ARC COE in Core to Crust Fluid Systems, Department of Applied Geology, Curtin University of Technology, Perth, WA Detrital origin of the rounded pyrite is also indicated by its geochemical characteristics (SAAGER, ).

The detrital nature of the Witwatersrand uraninite has been confirmed by its uranium-lead age of m.y., exceeding the age of the Witwatersrand sedimentation by about m.y. (Burger et. Other articles where Detrital grain is discussed: geologic history of Earth: Formation of the secondary atmosphere: early atmosphere is provided by detrital uraninite and pyrite and by paleosols—i.e., fossil soils.

Detrital uraninite and pyrite are readily oxidized in the presence of oxygen and thus do not survive weathering processes during erosion, transport, and deposition in an.

Pyrite is the most abundant ore mineral in gold-bearing quartz pebble conglomerates (QPCs) of the Witwatersrand Basin and similar Archaean sedimentary units.

Much of the pyrite in Archaean conglomerates is detrital in origin, implying that it survived weathering, transport, and reworking under anoxic conditions.

Pyrite rims on the detrital pyrites in the Witwatersrand CLR, plot with the bulk of the other orogenic deposit data. However, there is a vertical trend of some data that plots above the gold saturation line (Figure 10B).

These represent analyses of rims on detrital pyrite that include micro-grains of free gold. Geochemical and SEM analysis of the uppermost conglomerate (CG 4) indicate the presence of uraninite and coffinite within the uppermost horizon as both fillings of voids within, and coatings on, detrital pyrite grains.

Palaeocurrent data indicate a likely source terrain for the detrital material to the west of the inlier. Pyrite Meaning - At Energy Muse, our crystals and stones such as the Pyrite have the ability to release mental, physical, and spiritual blockages.

Learn more about the Pyrite meaning here. The evolution of the atmosphere has been of interest to many scientists because it relates to the history of the ocean, the sedimentary cycle, the geochemical cycle of volatile elements, and the. Pyrite, a naturally occurring iron disulfide mineral.

The name comes from the Greek word pyr, ‘fire,’ because pyrite emits sparks when struck by metal. Pyrite is called fool’s gold; to the novice its color is deceptively similar to that of a gold nugget.Geochemical and ecological aspects of lower Frasnian pyrite-ammonoid level at Kostom³oty (Holy Cross Mountains, Poland) Grzegorz RACKI, Agnieszka PIECHOTA, David BOND and Paul B.

WIGNALL Racki G., Piechota A., Bond D. and Wignall P. B. () — Geochemicaland ecological aspects of lower Frasnian pyrite-goniatite level.Rapid erosion and redeposition of pyrite-bearing rocks has resulted in preservation of detrital pyrite in many of the fluvial sediments, especially the fan deposits on the margins of rising basement ranges [23,27,37].

This detrital pyrite includes liberated particles that are typically sand-sized, but is dominated by remnant metamorphic and.