<DrumBeat: November 5, 2008 The Oil Drum What effect will the election results have on energy policy?- Open Thread>

114 comments on Jeff Rubin: Oil Prices Caused the Current Recession

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darwinsdog on November 5, 2008 - 1:49pm Permalink | Subthread | Parent | Comments top

When you get whacked hard on the forehead the concussion occurs on the occipital lobe. At the end-Cretaceous India was an insular fragment of Gondwana south of the equator in the Indian Ocean. Chicxulub rang the Ocean Planet like a bell, rupturing the crust on the opposite side, resulting in the Deccan Traps. Similarly, the Siberian Traps resulted from a massive impact at the end-Permian. Both basaltic outpourings were the result of bolide impacts - Chicx being an Fe-Ni bolide, hence the Ir enrichment and the end-Permian object most likely was a water ice comet. Large impact craters a quarter of a billion years old exist in Antarctica and in the Indian Ocean NW of Australia. Volcanism may have contributed to the extinction events but both volcanism & mass extinction were precipitated by ET impacts. Please don't conflate correlation with causation.

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Darwinian on November 5, 2008 - 2:40pm Permalink | Subthread | Parent | Comments top

Problem is Darwinsdog, that the impact happened a couple of hundred thousand years after the volcanism that caused th Deccan Traps had already started. The iridium layer thrown up by the Chicxulub impact is found smack in the middle of the Deccan Traps. A lot of volcanism before the impact and a lot of volcanism after the impact. You are making the exact same argument that I made before I saw the lecture and read the book. Watch the lecture DD, it explains it all.

The volcanism lasted several hundred thousand years.

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darwinsdog on November 5, 2008 - 3:14pm Permalink | Subthread | Parent | Comments top

Ir concentrations in the Cretaceous - Paleogene boundary clay varies from .1 ng g^-1 to 100 ng g^-1 worldwide. Rocchia et al. state: "A search for iridium in 47 samples from lava flows and inter-trap sediments in the Deccan yields negative results. Concentrations are not statistically different from zero, with a minimum detection level on the order of 0.1 ng.gāˆ’1 (ppb). This does not help to constrain the debate on the internal vs external origin of KTB boundary events..."

Rocchia, R., D. Boclet, V. Courtillot, and J. J. Jaeger (1988), A Search for Iridium in the Deccan Traps and Inter-Traps, Geophys. Res. Lett., 15(8), 812ā€“815.

Your assertion that "The iridium layer thrown up by the Chicxulub impact is found smack in the middle of the Deccan Traps" doesn't appear to be supported by Courtillot and his colleague's own research.

I own Courtillot's book, btw, altho it's been several years since I read it. Several hypotheses exist that purport to explain the K - Pg mass extinction. To my mind, none are compelling save the Chicxulub impact hypothesis. In fact, I believe that all of the previous major mass extinction events have been caused by extraterrestrial bolide impacts, with the exception of the currently ongoing anthropogenic event.

In grad school I modeled Milankovitch cycles as sine waves and again as terms of a Taylor series expansion, overlaid the cycles to see if any synergisms corresponded with mass extinction events. They didn't appear to do so. This result caused me to rule out orbital forcing as a cause of major mass extinction events.

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114 comments on Jeff Rubin: Oil Prices Caused the Current Recession

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