The religious nuts are sure in their knowledge-they know the age of the universe, heaven follows life on Earth (for the chosen), etc. etc.-they aren't interested in any info that might shake their rock solid belief system-just like you.

I have often changed my most firmly held beliefs. In fact I am always looking for data that will prove me wrong. That is the only way anyone ever learns anything.

An example: Concerning the great extinctions I was once the strongest advocate of the impact theory. I debated the the concept endlessly on the internet. Then I hear a lecture Vincent Courtillot , Universite Paris 7: "Mass extinctions in the Phanerozoic: a single cause and if yes which?" found on this page: Princeton University Archived Lectures That convinced me. I turned on a dime. The second greatest extinction coincided exactly with the second greatest volcanism, the Deccan Traps and the greatest extinction of all time, the great Permian Extinction coincided exactly with the greatest volcanism of all time, the Siberian Traps.

The lecture persuaded me to buy his book Evolutionary Catastrophes. Now I know people who still cling to the impact theory simply have not heard Courtillot's argument.

I have no sacred cows, no sacred dogmas, no firmly held beliefs that cannot be changed if the facts dictate. That is because I do not have a belief system other than that I believe only what the facts support. However I do have several hypothesis which are never held very strongly. They are mostly "perhaps this might be the case". Then after thinking about such a hypothesis I usually discard them as "not bloody likely".

Ron Patterson

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.

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.

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), 812–815.

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.

I believe the sun rises every morning at 2am. I have been proved wrong every time I set my alarm clock for 2:15 am, eager to rise and start my day at sunrise. I've had to wait for the sun until 6 or so. I have not given up my belief however because, when I sleep in to 8am, the sun is up and has been since 2am. I do not believe in intelligent design because of one simple fact; water does not run uphill. I've spent half of my life irrigating pastures, shovel in hand, trying my best to get water to flow uphill. No luck. In addition, I believe the earth was created, complete with all of it's creatures, six seconds ago. Prove me wrong. Best from the Fremont

Don't forget my favorite explanation for the dinosaurs' extinction - the Verneshot theory. It also may explain the 1908 Tunguska explosion.