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* End-Permian is associated with the Siberian Traps, but those in turn are associated with the Wilkes Land Crater impactor, which is antipodal to that event and
by mapt 2y ago
* End-Permian is associated with the Siberian Traps, but those in turn are associated with the Wilkes Land Crater impactor, which is antipodal to that event and may have seen antipodal seismic focusing.
* "Going on for thousands of years" - Dating the End-Permian has confidence intervals on the order of 30,000 years.
* Small size and diverse ecology almost guarantees survival of life. There is life basically everywhere we look, down to extremophiles living very slow lives in a random cubic meter of "solid rock" two kilometers deep. We have even evolved several chemical alternatives to photosynthesis as a primary energy source. Mammals and small birds deep in a cave somewhere appear to have been some of the only land vertebrates to survive K-T, and radiated out from there. Evolution does the rest.
- jordanb 2y ago> associated with the Wilkes Land Crater impactor Erwin discusses that theory but doesn't agree with it. In any case, 1) there are other mass dyings that are definately not impactors like the oxygen crisis. 2) there are other basaltic eruptions on the scale of the siberian traps (like CAMP) where the cause is known and not an impactor.
- blueflow 2y agoP-T is likely not due to the Wilkes Land crater, which would be 2.5x the size of the K-Pg impact and would have left an comparable amount (or more) of iridium in the boundary sediments. There are elevated iridium levels in the P-T boundaries, but only sporadically.
- mapt 2y agoThe theory being something along the lines of "Large mantle plume under Siberia suddenly freed when surface crust is fractured in numerous places by extensive antopodal convergence of shockwaves from the Wilkes Land impactor".
- jordanb 2y agoIf the Wilkes Land formation is an impact crater (not proven) it's 2x the size of Chicxulub. You don't need any vulcanization in Siberia to explain a mass extinction. But it's not proven to be an impact crater, nor is its age determined with any specificity. There's the lack of Iridium, and Erwin also had complaints about the modeling for an "antopodal convergence crack."