Publication Date:
2013-08-31
Description:
Twenty-eight years after one of us argued that Sudbury was an astrobleme, this interpretation has only recently attained wide acceptance; not so for the view that the Sudbury Cu/Ni sulfide ores are cosmogenic. Other research has provided the triggering of plateau basalts by super-large impacts a modicum of respectability. The recent apparent successful tying in of the K/T extinctions to the Chicxulub astrobleme in the Yucatan encourages the search for an impact event that may have caused the other two major post-Paleozoic extinctions (P/Tr, Tr/J). This gives us heart to offer two further outrageous hypotheses. The cosmogenic concept for the Sudbury ore deposite remains viable because it is giant, nonultramafic, and unique (except for Noril'sk). The Triassic/Jurassic boundary catastrophic extinctions have been attributed to the Manicouagan asteroidal impact, but recent radiometric dating indicates these events are diachronous (Manicouagan astrobleme 212 +/- 2 Ma and Tr/J boundary 200 Ma).
Keywords:
GEOPHYSICS
Type:
Lunar and Planetary Inst., International Conference on Large Meteorite Impacts and Planetary Evolution; p 22-23
Format:
application/pdf
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