Correlating Multiple Neoarchean-paleoproterozoic Impact Spherule Layers between South Africa and Western Australia
نویسندگان
چکیده
BETWEEN SOUTH AFRICA AND WESTERN AUSTRALIA. B. M. Simonson 1 , D. Y. Sumner 2 , N. J. Beukes 3 , S. Hassler 4 , I. Kohl 5 , S. Jones-Zimberlin 1 , S. Johnson 1 , A. Scally 1 , and J. Gutzmer 3 , 1 Geology Dept., Oberlin College, Oberlin, OH 44074 USA ([email protected]), 2 Geology Dept., Univ. of California, Davis, CA 95616 USA, 3 Dept. of Geology, Univ. of Johannesburg, Auckland Park 2006 South Africa, 4 J. F. Kennedy Univ., Pleasant Hill, CA 94523 USA, 5 Dept. Geol. and Geophys., Louisiana State Univ., Baton Rouge, LA 70803-4101 USA
منابع مشابه
Geochemistry and mineralogy of Early Archean spherule beds, Barberton Mountain Land, South Africa: evidence for origin by impact doubtful
Spherule layers in the ~ 3.4 Ga Barberton Greenstone Belt, South Africa, have been interpreted as being the result of large asteroid or comet impacts on the early earth. This interpretation was based, among other arguments, on the enr ichment of siderophile elements, especially the platinum group elements. We made a detailed mineralogical, petrological and geochemical study of spherule bed samp...
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We agree with Glikson [1] that the identification of Precambrian impact deposits is an important and largely unresolved problem, and thank him for providing us with an opportunity to further discuss our mineralogical and geochemical results [2] on the enigmatic spherule layers in the Barberton Mountain Land of South Africa. We note, however, that unfortunately Glikson has not been able to name ...
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The origin of multiple spherute-rich layers of millimeter to meter width, all occurring within the transition from the Fig Tree to the Onverwacht Group of the Barberton Greenstone Belt in South Africa, has been strongly debated during the last decade. One school subscribes to an origin by large meteorite impact, whereas others have preferred terrestrial processes. In particular, strong enrichme...
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This review of the current knowledge of impact spherule layers in the Barberton greenstone belt, together with new petrographic, geochemical, and field data on a number of impact and volcanic spherical particle horizons, highlight a number of problems with the proposition of frequent and large meteorite impacts during mid-Archean times. Field data indicate that some of the four previously propo...
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