Palaeoproterozoic magnesite: lithological and isotopic evidence for playa/sabkha environments
نویسندگان
چکیده
منابع مشابه
Osmium evidence for synchronicity between a rise in atmospheric oxygen and Palaeoproterozoic deglaciation.
Early Palaeoproterozoic (2.5-2.0 billion years ago) was a critical phase in Earth's history, characterized by multiple severe glaciations and a rise in atmospheric O(2) (the Great Oxidation Event). Although glaciations occurred at the time of O(2) increase, the relationship between climatic and atmospheric transitions remains poorly understood. Here we report high concentrations of the redox-se...
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The origin of the Proterozoic Choghart iron oxide deposit in the Bafq mining district of Central Iran has been the subject of a long-standing dispute. Some authors believe that it was formed from magma, while others suggest metasomatic replacement of preexisting rocks. The present study on the basis of new oxygen isotope, REE and geochemical data concludes that neither of these two hypotheses c...
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متن کاملExperimental determination of the equilibria : rutile + magnesite = geikielite + CO 2 and zircon + 2 magnesite = baddeleyite + forsterite
The P-T conditions of both equilibria were determined precisely by reversal experiments in a piston-cylinder apparatus. On the basis of 8 experiments, brackets for the rutile-magnesite-geikielite equilibrium are 7.0–7.1 kbar at 800 ∞C, 8.6–8.7 kbar at 850 ∞C, and 10.5–10.7 kbar at 900 ∞C. On the basis of 9 experiments, brackets for the zircon-magnesite-baddeleyite-forsterite equilibrium are 7.1...
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ژورنال
عنوان ژورنال: Sedimentology
سال: 2001
ISSN: 0037-0746,1365-3091
DOI: 10.1046/j.1365-3091.2001.00369.x