Reworking of atmospheric sulfur in a Paleoarchean hydrothermal system at Londozi, Barberton Greenstone Belt, Swaziland
نویسندگان
چکیده
منابع مشابه
3.5-Ga hydrothermal fields and diamictites in the Barberton Greenstone Belt-Paleoarchean crust in cold environments.
Estimates of ocean temperatures on Earth 3.5 billion years ago (Ga) range between 26° and 85°C. We present new data from 3.47- to 3.43-Ga volcanic rocks and cherts in South Africa suggesting that these temperatures reflect mixing of hot hydrothermal fluids with cold marine and terrestrial waters. We describe fossil hydrothermal pipes that formed at ~200°C on the sea floor >2 km below sea level....
متن کاملDepositional and tectonic setting of the Archean Moodies Group, Barberton Greenstone Belt, South Africa.
The 3.22-3.10 Ga old Moodies Group, uppermost unit of the Swaziland Supergroup in the Barberton Greenstone Belt (BGB), is the oldest exposed, well-preserved quartz-rich sedimentary sequence on earth. It is preserved in structurally separate blocks in a heavily deformed fold-and-thrust belt. North of the Inyoka Fault, Moodies strata reach up to 3700 m in thickness. Detailed mapping, correlation ...
متن کاملPetrology and Geochemistry of 3.3 Ga Komatiites– Weltevreden Formation, Barberton Greenstone Belt
Introduction: Komatiites provide several ways of assessing the chemical and thermal evolution of the mantle. Komatiitic liquids are produced from very high degrees of partial melting of the deep mantle, and erupted as extremely fluid lavas. Komatiites are important in the study of the early Earth because they are a significant constituent of the Archean crust. It has been proposed that komatiit...
متن کاملAtmospheric record in the Hadean Eon from multiple sulfur isotope measurements in Nuvvuagittuq Greenstone Belt (Nunavik, Quebec).
Mass-independent fractionation of sulfur isotopes (S-MIF) results from photochemical reactions involving short-wavelength UV light. The presence of these anomalies in Archean sediments [(4-2.5 billion years ago, (Ga)] implies that the early atmosphere was free of the appropriate UV absorbers, of which ozone is the most important in the modern atmosphere. Consequently, S-MIF is considered some o...
متن کاملArchean spherule layers in the Barberton Greenstone Belt, South Africa: A discussion of problems related to the impact interpretation
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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ژورنال
عنوان ژورنال: Precambrian Research
سال: 2016
ISSN: 0301-9268
DOI: 10.1016/j.precamres.2016.05.007