|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 Centre for Strategic Mineral Deposits, Department of Geology and Geophysics, University of Western Australia, Nedlands, WA 6907, Australia
2 School of Geosciences, Edgeworth David Building FO5, University of Sydney, Sydney, NSW 2006, Australia
The presence of detrital uraninite and pyrite in fluvial placers of the Witwatersrand basin, South Africa, has been used to infer low levels of atmospheric oxygen during the Archean (>2500 Ma). However, recent studies advocate a hydrothermal origin for these minerals, thereby limiting their value as constraints on the composition of the early atmosphere. In contrast, ca. 3250–2750 Ma fluvial siliciclastic sediments from the Pilbara Craton in Australia have never undergone significant hydrothermal alteration, and their heavy minerals are of unequivocal detrital origin. These heavy minerals include the redox-sensitive phases pyrite, uraninite, and gersdorffite, along with more inert zircon, rutile, chromite, and monazite. Locally, siderite is a major constituent (to 90%) of the heavy mineral population, with grains displaying evidence for several episodes of erosion, rounding, and subsequent authigenic overgrowth. Detrital siderite is very rare in post-Archean sandstones, largely due to its instability in oxidizing environments. However, its frequent survival of prolonged transport in well-mixed and therefore well-aerated Archean river waters that contained little organic matter strongly implies that the contemporary atmosphere was indeed much less oxidizing than at present. Moreover, concentrations of reduced sulfur species must have been very low in surface fluids for siderite to survive repeated transportation events without pyritization.
This article has been cited by other articles:
|
|
 |
|
  R. M. Hazen, R. C. Ewing, and D. A. Sverjensky Evolution of uranium and thorium minerals American Mineralogist, October 1, 2009; 94(10): 1293 - 1311. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. W. Fischer and A. H. Knoll An iron shuttle for deepwater silica in Late Archean and early Paleoproterozoic iron formation Geological Society of America Bulletin, January 1, 2009; 121(1-2): 222 - 235. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Kendall, R. A. Creaser, and D. Selby 187Re-187Os geochronology of Precambrian organic-rich sedimentary rocks Geological Society, London, Special Publications, January 1, 2009; 326(1): 85 - 107. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. M. Hazen, D. Papineau, W. Bleeker, R. T. Downs, J. M. Ferry, T. J. McCoy, D. A. Sverjensky, and H. Yang Mineral evolution American Mineralogist, November 1, 2008; 93(11-12): 1693 - 1720. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Buick When did oxygenic photosynthesis evolve? Phil Trans R Soc B, August 27, 2008; 363(1504): 2731 - 2743. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J. Formolo and T. W. Lyons Accumulation and Preservation of Reworked Marine Pyrite Beneath an Oxygen-Rich Devonian Atmosphere: Constraints from Sulfur Isotopes and Framboid Textures Journal of Sedimentary Research, August 1, 2007; 77(8): 623 - 633. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Jiao and D. K. Newman The pio Operon Is Essential for Phototrophic Fe(II) Oxidation in Rhodopseudomonas palustris TIE-1 J. Bacteriol., March 1, 2007; 189(5): 1765 - 1773. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. E Summons, A. S Bradley, L. L Jahnke, and J. R Waldbauer Steroids, triterpenoids and molecular oxygen Phil Trans R Soc B, June 29, 2006; 361(1470): 951 - 968. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. E. L. Minter The sedimentary setting of Witwatersrand placer mineral deposits in an Archean atmosphere Geological Society of America Memoirs, January 1, 2006; 198(0): 105 - 119. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Law and N. Phillips Witwatersrand gold-pyrite-uraninite deposits do not support a reducing Archean atmosphere Geological Society of America Memoirs, January 1, 2006; 198(0): 121 - 141. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Rasmussen Evidence for pervasive petroleum generation and migration in 3.2 and 2.63 Ga shales Geology, June 1, 2005; 33(6): 497 - 500. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. I. Groves, R. M. Vielreicher, R. J. Goldfarb, and K. C. Condie Controls on the heterogeneous distribution of mineral deposits through time Geological Society, London, Special Publications, January 1, 2005; 248(1): 71 - 101. [Abstract] [PDF]
|
|
|
|
 |
|
 A. D. Anbar and A. H. Knoll Proterozoic Ocean Chemistry and Evolution: A Bioinorganic Bridge? Science, August 16, 2002; 297(5584): 1137 - 1142. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 References Geological Society, London, Memoirs, January 1, 2002; 24(1): 119 - 125. [PDF]
|
|
|
|
 |
|
 G. L. England, G. L. England, B. Rasmussen, B. Krapez, and D. I. Groves The Origin of Uraninite, Bitumen Nodules, and Carbon Seams in Witwatersrand Gold-Uranium-Pyrite Ore Deposits, Based on a Permo-Triassic Analogue Economic Geology, December 1, 2001; 96(8): 1907 - 1920. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. E. Canfield, K. S. Habicht, and B. Thamdrup The Archean Sulfur Cycle and the Early History of Atmospheric Oxygen Science, April 28, 2000; 288(5466): 658 - 661. [Abstract] [Full Text]
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
