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RE: Why non-avian dinosaurs weren't able to survive
> From: Denver Fowler [mailto:email@example.com]
> Sent: Tuesday, November 24, 2015 10:56 AM
> To: firstname.lastname@example.org; email@example.com; firstname.lastname@example.org; email@example.com
> Subject: Re: Why non-avian dinosaurs weren't able to survive
> >> Additionally, there was a great physical destruction. Not much
> >> sediment.>Exactly: you only get fossils in a depositional
> environment. The effects of the Chicxulub impact didn't increase rates of
> sedimentation (well, except for tsunami deposits along the
> Gulf...), so you don't get any more chance of fossilization than other times.
> >Terrestrial deposition is very episodic and spotty: it isn't like deep sea
> >or lake sedimentation. You only get overbank deposits when
> the river floods; you only get channel deposits when the channel is RIGHT at
> that spot, etc.
> The uppermost Hell Creek (towards the K-Pg) is actually a period of high
> accommodation and significant deposition. The reason why
> the iridium layer & various ashes are preserved at the K-Pg (and a few metres
> above and below) is because there is deposition
> occurring. There is little evidence for any significant hiatus through the
> K-Pg in the Hell Creek.
High for a terrestrial deposit, yes. But as a once-paleoceanographer (not
entirely be choice...) I can tell you that with the exception of lakes, no
terrestrial form of deposition shows the kind of nearly-continuous
sedimentation you have in some marine environments.
Thomas R. Holtz, Jr.
Email: firstname.lastname@example.org Phone: 301-405-4084
Senior Lecturer, Vertebrate Paleontology
Office: Geology 4106, 8000 Regents Dr., College Park MD 20742
Dept. of Geology, University of Maryland
Faculty Director, Science & Global Change Program, College Park Scholars
Office: Centreville 1216, 4243 Valley Dr., College Park MD 20742
Mailing Address: Thomas R. Holtz, Jr.
Department of Geology
Building 237, Room 1117
8000 Regents Drive
University of Maryland
College Park, MD 20742-4211 USA