[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: mammals over dinosaurs in continuous sequence

> Danvarner@aol.com wrote:

> > Perhaps Jepsen is
> > describing a lack of mammals in Hell Creek deposits in Montana? Dan

Yes, it's actually the Hell Creek Formation that Jepsen was referring

jbois@umd5.umd.edu <John Bois> wrote:

> he goes on to talk about the underlying Lance formation and shell
> fragments "in the Dry Creek drainage..."

<oooh...my head...>    The Lance Formation does not underlie the Hell
Creek Fm.
The Hell Creek Formation and the Lance Formation are time-correlative.
Both formations contain what is called "Lancian-Age mammals", and this
is the standard Age used for all latest Cretaceous formations in North
America.  The Lancian Age is correlative with the upper zones of the
European Maastrichtian marine sections.

Jepsen's egg shell site is therefore in the Lancian Age Hell Creek
Formation.  If he had found the eggshells across the border in Wyoming,
it would have been in the Lancian Age Lance Formation (same geologic
time; different state).

John Horner wrote a very short blurb on Jepsen's egg shells in his first
book _Digging Dinosaurs_.
And no, the K/T boundary isn't found at the Jepsen site.