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I believe that the accepted theory for how Arizona's Grand Canyon was formed was that erosion caused by the Colorado River flowing through the area over millions of years was the force at work.

Yet accounts of a massive flood have been passed down to various peoples throughout the world, even in landlocked areas. Could the Grand Canyon actually have been formed by such a cataclysmic flood?

In either case, it is assumed that vast amounts of water formed the gigantic chasm; the main difference being: over how much time did the transformation occur?

If a global deluge were accepted as a possibility, is the condition and appearance of the Grand Canyon consistent with such an origin?

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    $\begingroup$ No, because 1) We have examples of what happens in a large outburst flood, such as Lake Missoula/channeled scablands and the draining of Lake Bonneville, and the structures left behind are much different. 2) There's nowhere upstream for the necessary amount of water to have come from. $\endgroup$
    – jamesqf
    Mar 28, 2016 at 18:48
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    $\begingroup$ It sounds like you might be getting at some sort of global 'Great Flood' hypothesis? If you're not, please edit it to indicate what non-biblical, scientific literature you have read — or what data you have collected — to lead to your theory. If you are, I'm voting to close this question as off-topic. $\endgroup$
    – Matt Hall
    Mar 28, 2016 at 19:12
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    $\begingroup$ @B. Clay Shannon: A global flood is disproven by everything from basic physics (where'd the water come from?) to biology (there are freshwater and saltwater fish). WRT geology specifically, there would be evidence of erosion and sedimentation everywhere, just not in the few places where we know that outburst floods have taken place. As for massive sustained rainfall, it takes energy to evaporate water to produce rain. No such energy source appears to have existed. About the closest you could get is a KT-sized asteroid impact, which would leave obvious traces. $\endgroup$
    – jamesqf
    Mar 28, 2016 at 23:17
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    $\begingroup$ While the answers are all basically no, ice age melt could have flooded the Colorado river many many times over the last 3 million years. And those floods very well could have played a role in the forming of the Canyon, but as others have said, a single flood or great deluge - no. It was formed over time. $\endgroup$
    – userLTK
    Dec 30, 2016 at 3:40
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    $\begingroup$ @userLTK: Not really that hard, at least for a geologist to get ballpark estimates. For instance, there's going to be a remnant lake basin somewhere upstream so you can calculate the amount of water released. There just isn't going to be sufficient energy in a single outburst flood to carve the whole canyon through rock. We do have good examples of such floods: the "channeled scablands" of eastern Washington caused by outburst floods from glacial Lake Missoula, and the Lake Bonneville flood: en.wikipedia.org/wiki/Bonneville_flood $\endgroup$
    – jamesqf
    Nov 5, 2017 at 18:37

3 Answers 3

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tl;dr: no.

Long answer:

First of all, like mentioned by others in the comments, you would need some physical mechanism to take a whole lot of water, evaporate it, and drop it at once at a place where the Grand Canyon is now. This is not something that's going to happen because of physics. If there was some extraordinary event which could have caused this, we would get so much more evidence from it other than the Grand Canyon.

But let's assume, that somehow, by some magic or act-of-higher-being, an enormously large amount of water fell on the Colorado plateau at once. How would that look?

  1. The huge amount rock removed from the plateau to form the canyon would have to go somewhere. And it would go there very violently, as huge boulders, irregular conglomerates and just a whole mess of mixed up geology. However, when you look downstream along the Colorado river, you don't see this stuff anywhere. When you look in the Gulf of California (which we know very well because of oil exploration), you don't see this stuff in there. Instead you see very nice sandstones, shales, marls, clays, etc. Definitely stuff that should not be there if there was a huge flood. Furthermore, those sedimentary rocks are interbedded with volcanic rocks and limestones. If this was a sudden event, all of this could not be there.
  2. The Colorado river is meandering. If it was a huge sudden flood you would not get this morphology.
  3. So far I was talking about lack of evidence. There is also some direct evidence for the incision rate of the Grand Canyon. Using a plethora of of scientific methods, such as radioactive isotope dating, cosmogenic dating, thermoluminescence, etc., it's possible to directly get a time when a certain thing happened (depending on the method). This allows us to know exactly when a certain rock formed, exposed, eroded (again, depending on the method). Using these scientific methods allowed us to infer that the Grand Canyon formed in the last several few million years, at an incision rate of a few dozen to a few hundred metres per one million year. The value depends on the exact location in the Grand Canyon and also on which research group you're asking. But whether the argument is about if it's 100 or 200 metres per million years is irrelevant for this discussion - it invalidates any suggestion that it formed in one sudden magical act of flood.
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    $\begingroup$ One nitpick: The Colorado River drains into the Gulf of California (or used to, before it all got pumped to Los Angeles, Las Vegas, &c), not the Gulf of Mexico. $\endgroup$
    – jamesqf
    Mar 29, 2016 at 18:13
  • $\begingroup$ @jamesqf of course. I was thinking one thing and writing another. :) $\endgroup$
    – Gimelist
    Mar 29, 2016 at 22:39
  • $\begingroup$ Yeah, I've been known to do that too. But it raises another objection to the rainfall hypothesis. Unless the rain were somehow (I tempted to write 'miraculously' here :-)) localized, there should be a similar canyon & associated erosion on the east slope of the Rockies. And of course localized rainfall violates the global hypothesis. $\endgroup$
    – jamesqf
    Mar 30, 2016 at 5:17
  • $\begingroup$ Just a vocabulary nitpick: "plethora" means "too many". Something like "various" would be better. $\endgroup$
    – Spencer
    Dec 30, 2016 at 4:04
  • $\begingroup$ @Spencer that's what I mean. A more-than-really-required variety of methods show that there was no flood. $\endgroup$
    – Gimelist
    Dec 30, 2016 at 4:18
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In addition to all of the above there are meanders inn the Grand Canyon which are hydraulic outcomes of 'minimum energy flow configurations'. This constrains the discharge rates that are possible - to within the normal range of hydrologic discharges. Furthermore there are several places in the Grand Canyon where there is clear evidence of the river having been dammed by lava flows, over 13 volcanic episodes. These volcanics have been K-Ar dated at a variety of ages over the last few million years, with each lava dam taking between 10,000 and 20,000 years to erode. See, for example http://www.ncbi.nlm.nih.gov/pmc/articles/PMC21407/ and several other books and papers on the subject.

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There is evidence that at least part of the erosion in the Grand Canyon was caused by an outflow flood caused by the failure of a lava dam. https://www.gcrg.org/bqr/18-1/lava.html

There is speculation that glacial lake outflow floods from the glaciers in western Colorado at the end of the last ice age could have contributed as well. More study is needed to prove or disprove that one.

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