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Australia: The Land Where Time Began |
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Siberian Traps Flood Basalts - Rapid Eruption at Permian-Triassic Boundary The Siberian Traps are one of the most voluminous flood basalt provinces on Earth. Data obtained by laser heating 40Ar/39Ar indicate that the bulk of these basalts was erupted over a period of time that was extremely short, 900,000 ± 800,000 years, beginning at about 248 Ma with mean eruption rates of more than 1.3 million cu km per year, the authors1 suggesting this is consistent with their origin being a mantle plume. Significant lithospheric rifting was not associated with this magmatism, therefore mantle lithospheric decompression that resulted from rifting was probably not the primary cause of the widespread melting. Initiation of the volcanism that produced the Siberian Traps coincided (within uncertainty) with a severe faunal mass extinction event at the Permian-Triassic boundary 249.4 ± 4 Ma, the authors1 saying these data thus leave open the possibility of there being a genetic connection between the 2 events.
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Author: M.H.Monroe Email: admin@austhrutime.com Sources & Further reading |