Posted on 09/21/2005 10:32:02 PM PDT by SunkenCiv
In the final section of the book, Powell takes his thesis beyond the comfort zone of many scientists, even some of the supporters of the K-T impact, and argues that impact was a factor at not only the K-T boundary but in many, perhaps most, of the other mass extinctions. To do this he relies on the periodic extinctions in the marine fossil record documented by Jack Sepkoski, the growing number of documented terrestrial impact sites and David Raup's provocative kill curve, which shows the average time between extinctions of different magnitude. Powell is certainly not the first to make this leap, but he makes it gracefully. The last chapter is a call to action and rightly argues that many of the questions raised in the K-T debates of the past two decades are resolvable by focused research. Although this reads like the conclusion to a grant proposal, it does allow the book to end with a clear idea of what we should do next.
(Excerpt) Read more at americanscientist.org ...
Night Comes to the Cretaceous
by James Lawrence Powell
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Night Comes to the Cretaceous[W]ith no generally accepted explanation for the dinosaurs' sudden demise, there was no broad, unified defense of an alternative to the Alvarez proposal. Nevertheless, as Powell documents, it was no easy road to acceptance of the idea, especially among paleontologists. One prominent astronomer even argued against the impact hypothesis... Powell finally realizes that the burden of proof has shifted to the anti-impactors... This is a well-written, intelligent book, accessible to the interested layperson but also fully footnoted for geoscientists who want more technical details. It is a thorough account of that portion of the K-T battle, now won, that was fought on a geological turf.
by James Lawrence Powell
reviewed Nov. 24, 1998
by Clark R. Chapman
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Red Nova | September 15, 2003
Posted on 09/15/2003 8:48:14 PM PDT by UnklGene
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I pterosaur a puttie tat.
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