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

RE: Gastroliths



At 09:54 AM 4/6/99 -0500, King, Norm wrote:
>The claystones of the Morrison are not really aquatic deposits.  They may
>have been deposited on river flood plains, but the setting was terrestrial.
>In addition, many of them are paleosols, reflecting pedogenic processes more
>than original depositional conditions.

Having seen part of the Morrison in person, I can say that this certainly
matches my impression.  In fact the outcrop I am familiar with is almost
entirely paleosol in my estimation, with only a few thin channel/crevasse
sand bodies near the lower part of the outcrop.  Since I was within a mile
or two of the Morrison type locality, I suspect this is fairly typical.

[I really pulled a joke on myself there too - I found an in-situ dinosaur
bone, and thought it was fossil wood for several minutes].

>  The limy deposits I am familiar with
>formed on shallow lake beds, and they were often hypersaline, complete with
>algal stromatolites.

Another *possible* source for limey deposits in a semi-arid zone like, the
Morrison area 130 MYa, is caliche, that is pedogenic processes.  I cannot
say that such exists  in the Morrison, but it would not surprise me if it did.

--------------
May the peace of God be with you.         sarima@ix.netcom.com