Re: Travertine / Article in Natural History Magazine

David Yeamans, CST-7, 5-8832, dryeamans@lanl.gov (dryeamans@lanl.gov")
Wed, 01 Oct 1997 08:10:20 -0600


I responded to Perry's request for evidence of ponding. I posted the reply
to the wrong person/group. You have a great deal of evidence stacked up and
it is a credit to your interest in the canyon and it is a piece of evidence
in favor of having a faster turn around on the wait list. There is nothing
like repeat trips, even several in the same year, to congeal a pet theory or
to gather evidence.

>Very likely in recent geological time
>>"reservoirs" due to damming of the river by basalt flows have been a
>>fairly common occurrence.
>
>It's the ponded water from these that may have been involved in cementing
>the colluvium near the Little Colorado.

The shield of travertine on the south shore near Elves Chasm below the
Redwall _may_ be evidence of ponding. I can't think of another mechanism to
explain it. Suppose that carbonate-rich water exudes from the redwall at a
point source such as Elves Chasm or Tapeats and falls into low-pH
(CORRECTION -- HIGH-pH) water such as might be present in a lake on the
Colorado. Viola`, we have CaCO3 dropping out of solution and acreting
itself in shelves such as are seen in the area described and in limestone
caves in the Guadalupe Mountains of New Mexico. One such form is called
Coat Tables, and marks the surface of ponds.

PBS aired a program written by a group of geologists from Iowa or other
east-of-the-crick state. The main professor was such an experienced boatman
after two trips that he took his own boat down the canyon and when it got
into trouble, he "jumped out of the boat to save the boat." Anyway, perhaps
this fellow can show us evidence of ponding.

Dave Yeamans

>Return-Path: <RealDriftr@aol.com>
>From: RealDriftr@aol.com
>Date: Tue, 30 Sep 1997 20:47:22 -0400 (EDT)
>To: dryeamans@lanl.gov
>Subject: Re: Travertine / Article in Natural History Magazine
>
>David - I missed your earlier message, but am interested in the travertine
>shelves @Elves Chasm and other places in Grand Canyon:
>1.) river left from Kwagunt to Little Colorado and up the LC for 3/4 mile
>along the same wall
>2.) on river left between Hermit and Boucher Rapids
>3.) several places below Diamond Creek, including river left just above
>Quartermaster and on the right across from Emory Falls.
>4.) and of course the major travertine shelves at Mooney and Beaver Falls in
>Havasu canyons.
>5.) the shelf in the Meriwhitica Canyon (tributary of Spencer Canyon)...
>
>Anyway, I've been wondering about this stuff for past 25 years....I've heard
>(but can't remember where) that the Mooney and Beaver Falls travertine shelfs
>correlate with the levels of a couple of the lava dams. The deposit along
>the wall on river left above Elves is on top of - and apparantly filled - an
>old river channel. The old river bed is well exposed along the trail that
>heads upstream from Elves...
>
>The Lava Dams, of course, didn't create a lake below Diamond Creek.
>
>I've always thought that all of these must be somehow related in terms of how
>they formed, although I'd guess that the mechanism (whatever it was) may have
>been invoked by different events, at different times, in different places.
>
>Anyway, would be interested in any thoughts you might have....
>
>The travertine between Kwagunt and the LC appears to have been deposited by
>water running down a slope (not into a lake) and I've always thought the
>source was piping from the cliff collapse dam at Nankoweap...
>
>Yours truly - Drifter Smith
>
>

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