Re: preserving raindrops and mats

Glenn Morton (grmorton@waymark.net)
Tue, 20 Jan 1998 22:32:14 -0600

At 07:47 PM 1/20/98 -0800, Arthur V. Chadwick wrote:
>At 06:20 PM 1/20/98 -0600, Glenn wrote:
>
>>We can tell the difference between the two.
>
>I don't exactly know who the "We" is, but I know that for many generations
>the literature has not distinguished them, even after they were recognized
>as sedimentary features. The best example of synaresis (thanks, Glenn!)
>cracks I know of are the giant ones at the base of the Coconino in Grand
>Canyon, although they are not described as such, because they have not to
>my knowledge been studied since subaqueous mud cracks were described in the
>1970's. They are one generation, irregular in shape, not polygonal, very
>deep with parallel sides, and filled with the overlying Coconino Sand.

At the base of the Coconino is the Hermit shale. What is the widely
accepted environment of deposition for the Hermit? Isn't it marine? I
didn't look because I figured you knew. If it was marine, then synaerisis
cracks would be expected but this would have nothing to do with the
overlying Coconino which, filling the cracks, came later than the Hermit
depostion.

glenn

Adam, Apes, and Anthropology: Finding the Soul of Fossil Man

and

Foundation, Fall and Flood
http://www.isource.net/~grmorton/dmd.htm