Re: Mongolian carbonate concretions

Arthur V. Chadwick (
Mon, 02 Feb 1998 09:36:13 -0800

At 09:47 PM 1/30/98 -0600, Glenn wrote:

>I would disagree with your logic above. Coal balls don't preserve the shape
>of either the fern leaves or the larvae. But rhizoliths preserve the
>dendritic pattern of root systems. Little in this world except plants have
>this pattern.

Lets consider burrows as another possibility, but dendritic patterns are
one of the most common patterns in nature. They are among other things, a
common manifestation of chaotic patterns that could be an indicator of
nothing in particular.

>The lack of glauconite in these Eolian deposits and its presence in other
>rocks in the same area such as the Muav limestone of the Grand Canyon. What
>sourced the Mauv and didn't source the Coconino or Navajo?

Nobody has ever suggested the Navajo or Coconino had teh same source as the
Tapeats. By the same token, nobody has ever traced with confidence the
sources for any of these sediments. For example, one theory is, since
there is a possible source area in the south, the sand blew to north of the
basin, then was transported back to the south by the water. Now that makes
a lot of sense, doesnt it??? :-).