Category Archives: Grand Canyon

A River Runner’s Guide to Grand Canyon Geology IV: Whither the Supergroup?

Posted on September 24, 2019 by gymnosperm

We left off the last post having seen the complete Supergroup sequence of over two miles of Neoproterozoic and Mesoproterozoic sediments. The river never encounters the Neoproterozoic part, roughly half. These lie above the river on the North Rim side … Continue reading →

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A River Runner’s Guide to Grand Canyon Geology III: The Supergroup

Posted on September 17, 2019 by gymnosperm

A typical visitor to the Grand Canyon looks down from the rim through about a mile of sediments to the river. Most of these are Paleozoic sediments extending back about 515 million years. They appear to be level, although in … Continue reading →

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A River Runner’s Guide to Grand Canyon Geology II: Muddy Creek and the Formation Problem

Posted on June 28, 2019 by gymnosperm

One might think that by now we would understand pretty well how the Grand Canyon formed. We don’t. Central to the problems of how and when the current Grand Canyon formed is the Muddy Creek Formation, a bunch of freshwater … Continue reading →

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A River Runner’s Guide To Grand Canyon Geology

Posted on June 25, 2019 by gymnosperm

River runners have a different perspective on Grand Canyon geology. Remarkably, the put in at Lee’s Ferry is above the entire Grand Canyon sequence, and all the strata seem to emerge in turn from the river. This makes sense, but … Continue reading →

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Entropy and the Grand Canyon II

Posted on June 25, 2018 by gymnosperm

We left off in the last post having boated 78 miles, about five days on a typical trip, and having encountered the last of the suite of three books that comprise the geological story revealed in the Grand Canyon. We … Continue reading →

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Entropy and the Grand Canyon

Posted on June 20, 2018 by gymnosperm

It has been our good fortune to row 280 miles of the Colorado River through the Grand Canyon twice in the last seven months. This is rare for private boaters limited to one trip per calendar year and subject to … Continue reading →

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River of Time

Posted on October 11, 2017 by gymnosperm

I’ve been rowing the Grand Canyon for about a month. Sixteen of us were on the river for 20 days. It takes a couple days to drive there and a couple more to drive back. It takes a day to … Continue reading →

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How Old is the Grand Canyon?

Posted on December 4, 2012 by gymnosperm

Controversies over wonders of the world capture the public imagination from time to time. Now some Caltech scientists have dared suggest from a new technique that measures the depth of overburden on apatite crystals that there was an older canyon … Continue reading →