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You've got a lot of ifs in your erosion-uplift ratio, but apparently you have no problem assuming the "right" ratio against all probability, even when the river finds itself clinging to a slope that slants away from its own course. Oh well.

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Not really. All we need is the erosion to be fast enough to keep pace. That's not a huge 'if' and you don't have anything even close to as good. Try counting the 'ifs' in your preferred explanation in the same way and see where you get.And the river doesn't cling to the slope, it cuts into the slope as it develops. So long as you fail to understand that you're going to waste your time making arguments that miss the target.

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The shape of the river, meanders and all, isn't going to be maintained through the cutting of a stack of layers a mile deep,

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The evidence would seem to show that it has. This isn't a dogma, it's just the only thing that accounts for the evidence.The meanders were cut by the river. There are no deep cuts showing earlier courses. Deal with those facts.

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meanders themselves often don't stay meanders, according to Wikipedia on the subject.

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Read up on incised meanders.

No; the river was there before the uplift. We've explained how it works. With diagrams. Faith, what do you think a river is?

Perhaps it is because you are wrong. This is wrong And this is wrong.They are wrong not because we interpret things that way, they are wrong because that is not what the evidence shows happened. good start But since the river was before the uplift it didn't have to do that.How much uplift a year Faith?The measured rate is a few millimeters per year ... less than an inch. So let's start with an inch to be on the wild side ...If a section of river bottom rose 1" over a 10 foot span what would be the effect on the river?How about 1" in a hundred feet?Would it raise the surface of the river? Not noticeably.Now the same cubic feet of water needs to be delivered or you will be backing up the river, so what happens is that the river speeds up. If the cross-section of the river is 90% then the speed of the river is 111%.You can observe this behaviors in rivers all over the world where they pass from deep sections to shallow sections. Basic hydrodynamics. And you can measure the erosion rates. This is not imagination or interpretation it is the evidence gathered from how water and riverbeds behave.You can draw an energy gradient for the river that reflects where the surface level should be along the river -- that slide show I reference in Message 319 shows this information ...The faster water erodes faster so the bottom and sides in the uplift area are eroded faster than the riverbed upstream of the uplift. Downstream the river speeds up where it returns to non-uplifted depth, and so it erodes in this location more than the location of the uplift and this rapidly (and it can cause rapids) moves upstream until the old riverbed bottom is restored.Compare this to a boulder falling in the river and blocking part of the riverbed. The water increased velocity in that location and that increases erosion until the riverbed is the same size as before.Uplift is small and gradual. And when did that slope occur, Faith? In a flat floodplain where was the slope before the uplift?Remember you have tributary rivers coming in to the Colorado from both north and south, two of them fairly substantial -- how could they run uphill to get to the Colorado?Because back when the uplift was just beginning they already had their channels to the Colorado, their riverbeds. ... Message 319:

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Third, the tributary area and streams were also being lifted so the pattern of drainage would not be altered appreciably - water would continue to flow to the tributaries and the main river.

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This is a downloadable powerpoint slide show with a lot of general information as well as two pictures pertinent here -- slides 12 and 13:

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How do you explain Kanab Creek and Meadow Creek Faith? Particularly Meadow Creek that flows north from the area south of the Grand Canyon ...Not surprisingly, geologists and hydrologists can explain them by the same processes as the Colorado, the same effects on flow, river energy gradients and erosion during the gradual uplift of the whole area. Here is slide 5 from the slide show:

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Notice how the surface of the water does not follow the bottom. Section 1 would be an excellent description of the annual effect of uplift on the bottom resulting in faster flow and erosion compared to section 2 each side of the uplifted area.Now I don't expect you to learn all there is to know about hydrodynamics, I just expect you to understand that this is stuff that is well known by engineers and scientists. Engineers use this information every day to design water channel systems, and it is basic knowledge that is developed from the physics involved. Now it is my experience that engineers tend to use things that work and avoid those that don't work -- so we can be sure that these equations and description of water behavior do in fact work, that it isn't a matter of interpretation. You've been pretending to know what happened without understanding the evidence of what happened. You think - by the implications of what you say - the uplift created a dam that blocked the flow. You think - by the implications of what you say - that the surface of the water rises with the uplift and flows over the sides. Both of these are false concepts because

• Uplift doesn't operate that fast, it's only a few millimeters a year, and
• Water doesn't behave that way, the surface is determined by the energy equations that take into account changes is velocity,
• There are other common behaviors of streams that operate faster in geological time and affect streams to a greater extent, like collapsing banks, that don't necessarily cause rivers to overtop their banks - this is how ox-bow meanders are eliminated ...

You can't convince us with demonstrably erroneous thinking and false portrayals Faith, you need to use real information in your 'critique' of 'OE theory' -- which is also a fragment of your imagination - the theory applicable here is uniformitarianism:

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Uniformitarianism is the assumption that the same natural laws and processes that operate in the universe now have always operated in the universe in the past and apply everywhere in the universe. It has included the gradualistic concept that "the present is the key to the past" and is functioning at the same rates. Uniformitarianism has been a key principle of geology and virtually all fields of science, but naturalism's modern geologists, while accepting that geology has occurred across deep time, no longer hold to a strict gradualism.

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If you don't understand the theory you can't properly criticize it.Enjoy.Edited by RAZD, : ...Edited by RAZD, : .

I know others have already said this, but I'm going to say it again in the hopes that, if you read it enough times, you will actually understand what is being said instead of reiterating your misguided notions of uplift and hydrodynamics. Let's do it in point form so you don't get confused. Then you can pint out the parts you don't understand.1. The river originally flowed in a meandering path across a flat plain
2. Uplift began to occur
3. Uplift was slow (a few millimeters/year as RAZD has explained)
4. As the ground rose minutely, the river cut into it
5. As the channel became deeper, changes in course became increasingly unlikely and eventually more or less impossibleYou seem to be clinging to the notion that uplift occurred rapidly and so the river would have flowed off the sides or back down the slope. But this is a fantasy that is in opposition to actual observations of rates of uplift. You've also still refused to address the point that the entire canyon follows a meandering path, a fact which is consistent with our explanation by utterly inconsistent with yours. I'm surprised others aren't putting more pressure on you about this considering it pretty handily refutes what you imagine must have happened.

Hi Faith,The problem seems to be that you believe we're trying to convince you that flowing water all by itself can erode through rock. You're correct in believing it would take an exceedingly long time, and if that's what you think we're saying then the difficulty you're having accepting it is understandable.But we're not saying that water erodes rock into canyons. We're saying that *rivers* erode rock into canyons, and rivers will contain a great deal more than just water. The more rapidly moving the river, the greater the sediment load, and the water-borne sediments of a moving river are a great cutting force.Have you ever noticed the smooth pebbles on river bottoms? They began life as larger rocks but were gradually eroded into smooth pebbles by being carried along with the current and bumping into other rocks, pebbles and river bottom. Each collision chisels off minute pieces of rock, and this grinding is what makes them smooth. When a rock or pebble collides or bounces along the river bottom, corresponding minute pieces of rock are removed from the river bottom.The greater a river's speed the greater the amount of sediment it can carry, and the spring floods that used to occur at the Grand Canyon carried sediment loads capable of cutting through feet of rock in mere hours, but more moderate flows will still wear away the river bottom. Here's a description of the Colorado from Grand Canyon: The Complete Guide - Grand Canyon National Park: So whenever the Grand Canyon region uplifted an inch, the Colorado had little problem eroding away an inch of rocky river bottom. Once canyon formation had begun in earnest, even had there been years of incredible uplift of multiple feet I doubt it would have presented much of an obstacle. The Colorado would have pooled behind it and then spilled across and cut through like a buzzsaw during the spring floods.Another thing I can see you're having trouble accepting is how the changing course of a river can establish itself into a permanent channel etched into rock if it took millions of years instead of happening suddenly. But when the Colorado first flowed through the region of the Grand Canyon it was not flowing over rock but soil. As the region gradually uplifted the Colorado eroded more and more deeply into the soil, eventually deeply enough that changing course became very unlikely. Finally it eroded deeply enough to reach rock and continued eroding into it.--Percy

While the uplift that caused the Grand Canyon only began after all the sedimentary layers had been deposited, that isn't to imply any connection between the two. There were many periods of uplift and subsidence in the region while the sedimentary layers were being deposited, and this is recorded in the observed unconformities.Also, I must have used some unfortunate phrasing somewhere that has caused you to think I'm characterizing rivers as being *forced* to erode through uplift. Rest assured that I'm not saying this. The erosion of rivers through uplift is a natural process.--Percy

No, I'm simply FOCUSING on the uplift that is illustrated in the cross-sections. I gather that particular mounded uplift occurred right where the canyon cut from east to west. You and RAZD seem to be talking about a more general uplift that covered more territory.

Good GRIEF, how are you getting anything ELSE out of what you just quoted from me? I KNOW the river was there before the uplift, everything I've said assumes that. NOTHING in that quote says otherwise. I'm trying to make a distinction between a huge inrush of water from many directions, from north and south and east into the canyon area at least, because I'm thinking of standing water to some depth over that whole region, which runs into the cracks that open up in the strata. as versus a river which runs in one direction, east to west in the case of the canyon, except for meanders and switchbacks of course, which I guess I have to say or someone will come along and accuse me of thinking purely "linearly." Edited by Faith, : No reason given.

The illustration of the cross section through the Grand Canyon should not be interpreted as indicating that the uplift occurred only at the Grand Canyon. As stated earlier, the uplift affected an enormous area, and it is shown on this topographical map of Arizona: This large uplifted region stretches all the way from Arizona's northern border down through Flagstaff and then continuing further south and east toward New Mexico. It includes the Grand Canyon region.--Percy

OK, of course that's OE theory, I only confused things by putting it the way I did. You actually said the uplift of the land "forces" the water to cut into the rock, but I haven't been able to find that post again.I'm not going to say any more about any of this. The confusions are getting out of hand.

So the cross-section means absolutely nothing I guess. Why bother making a cross-section at all?

Here's a nice video on meanders and uplift, showing non_GC incised meanders. Won't affect Faith, of course.

The last part of your first quote made it sound like you thought the river could never have been established there because of the uplift. I originally had the same interpretation as Dr Adequate, but it appears now that you only meant that once the uplift began that the river would have been diverted.But uplift is gradual and rivers have no trouble eroding through gradual uplift. See my earlier message about how rivers effect erosion.--Percy

Hoo boy, well I see where you get your view of meanders. So somehow the Colorado River was already at the level of the Tapeats or lower or whatever it is, and the strata just grew up all around it to its current depth of a mile to the Kaibab rim, or what? I mean he makes a point of saying the river was always at the level it is.Edited by Faith, : No reason given.

So to be clear, I never "agreed that it took a billion years of the strata all building up before the uplift began to occur...", thereby implying some connective relationship. Obviously there was a billion or so years between the forming of the lowest layers and the uplifts that later caused the Grand Canyon, but there were uplifts and subsidences all through the time that the layers were being deposited. If I said that then it was an unfortunate way to phrase it, but I don't think it's important to track down the source of the confusion. What's important is to make sure the confusion has been resolved. Rivers have erosive power, and uplift will change the topography in a manner which focuses that erosive power most on the uplifted portions. Rivers will flow faster through parts of the uplifted portion, and the sediment carried by the river will cut faster into it and gradually cut upstream until the river bottom is at the same height as before, more or less.--Percy