Summations Only

As I am probably way too fond of saying, things that have actually happened leave evidence behind. We have, literally, trillions of tons of evidence. We have here-and-now observations of rivers and canyon formation, we observe the types of evidence they leave behind, and we find that evidence of what happened in the past buried in the ground. Well, I'm sure this comes as a surprise to everyone, especially me. First, geological disturbances that occurred during their formation *are* found in the strata. And second, a layer might form in just 10 million years, and so there are only 10 millions years of whatever the odds are of a major geological event during it's formation. But then the layer sits beneath the ground for 300 million years, which is 30 times greater odds of a major geological event after it forms than during.You would make as much sense expressing suspicion that most things seem to happen to people after they're born instead of before. A more accurate characterization might be made-up stuff against knowledge built upon a foundation of centuries of evidence and study.--Percy

It's puzzling that you describe this idea as daft, because it's something very simple. Did you ever play with making dams as a child? Maybe at a tiny creek, or in the springtime as the snow melted? Do you remember what happened as the tiny dam filled up and eventually overflowed? Do you remember the water overrunning the top at one point, then eroding a notch that quickly grew ever wider and deeper as the water rushed through with increasing force and speed?It's the same with a river flowing through a region that has recently uplifted a small amount, say a few inches after an earthquake. The river will form a pool behind the uplifted region, because the uplift acts like a partial dam. But because just as much water must flow to sea as before, the water must flow through the uplifted region with greater speed and force, and at the end of the uplifted region the water will flow with even greater speed and force because of the drop off from the greater height of the uplift.You can demonstrate this to yourself with the device I showed before: You don't need a real one like this, just construct a simple one in your garden. Create a downward slope with a drop of a few inches over 4 or 5 feet, then put a garden house at the upper end and turn on the water. A river will gradually form.Now fake an uplift by slipping a trowel beneath the river somewhere around the halfway point, and leverage the trowel up slightly to lift the riverbed a half inch or so. Observe the river erode through the uplift.If you instead leverage the trowel up a great deal to create the effect of an insurmountable uplift then the river will change course and go off in another direction, which is the other scenario you've mentioned a number of times. This can happen too, no one denies this, but you can't grasp onto it as if it were the only thing that can happen. It is only one of things that can happen, and in the case of the Colorado, where it is now is where it was successful in eroding through the uplift. But a river doesn't have to keep a course for millions of years to cut deeply. Most rivers do not begin by flowing through rock, as we see the Colorado do today in the Grand Canyon. In its earliest days it flowed along through much softer material, namely soil.So initially the topmost layers of any gradually uplifting region are going to be soil. After enough time passes with continued uplift a meandering river will erode down through the soil to create deep banks from which it is very unlikely to escape. If the uplift continues long enough eventually the river will erode to the bottom of the soil and be into rock, with banks now so deep as to be a very persistent feature on the landscape, and once the river erodes deeply enough into the rock its meandering course will be permanently etched.The catastrophic flow of water you think is needed to create the Grand Canyon could not have created the meanders, and certainly not the tightly meandering canyons of the San Juan River.--PercyEdited by Percy, : Clarify.

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

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

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

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

Of course the illustration of the cross section at the Grand Canyon means something. But why would you think a map of the Grand Canyon would tell you anything about parts of Arizona that aren't on that map? It's also sort of a composite intended to communicate layer information, not map information. For example, the Vermilion Cliffs are not on a straight line from the Grand Canyon to Brian Head Peak.--Percy

Hi Faith,I didn't say uplift was like a dam. I described a play dam a child might build being overflowed and then being eroded away, because I thought that if you had engaged in such play as a child that it might be a helpful analogy, and then I said uplift is like a partial dam in that the water would flow over it and be eroded away. If the analogy doesn't work for you then we should move on. You're correct that doesn't act like a dam, but it does interfere with the flow of water. The more the uplift the more the flow of water is impeded. The water will have a higher level and greater speed through the uplifted portion of the river (lower volume means greater speed because the same amount of water has to flow through), it will be able to move more and heavier sediment with greater erosive effect, and at the end of the uplift it will drop across a greater height also with greater effect. "Serious uplift" sufficient to divert the river is something that can happen, but it is not the only thing that can happen, plus it is much more rare than gradual uplift. There are many regions around the world experiencing gradual uplift or subsidence. Only very occasionally is there a geologic event causing uplift sufficient to divert rivers. Rivers deeply incised into landscapes are evidence of gradual uplift.--PercyEdited by Percy, : Clarify.

You had argued how unlikely it was that the uplift would have occurred only beneath the Grand Canyon unless it had some specific cause that we were refusing to acknowledge, so I provided the topographical map of Arizona so that you could see that the Grand Canyon is just a small portion of a very large region of Arizona that has been uplifted.--Percy

Meanders are caused by slow moving rivers across flat landscapes.--Percy

As I asked once before, why are you seeking natural answers about the Grand Canyon that only raise contradictions. Why is the answer not, "God."--Percy

Hi HBD,I'm having trouble interpreting these maps the same way you are. Looking at the description of the first diagram from Distribution Of Ordovician Rocks. American, horizontal lines are areas that were submerged during the Ordovician, white regions are areas that were land during the Ordovician, and black is rock from the Ordovician that is exposed at the surface today.--PercyEdited by Percy, : Make more clear.

No, no misreading. Back in Message 367 you said that you were talking only about uplift at the Grand Canyon and not about the more general uplift that RAZD and I were talking about. But the uplift at the Grand Canyon is just one small portion of the general uplift. It was not a separate uplift.This is why your earlier claim was wrong that some force we were ignoring acted on the supergroup beneath the canyon and caused the uplift there. The entire region was uplifted, not just the Grand Canyon area.--Percy

There's no such thing as "OE theory". There exists no body of scientific thought centered around a hypothesis that asks, "What if the world were ancient?" There are only theories that are accepted because of the evidence behind them, and these are the theories and evidence we've been presenting to you. We're already familiar with YEC views. What we're not familiar with is YEC evidence, because none is ever presented. What is presented instead is imaginings like this: What any evidence suggests to you is of no consequence because you have no geological knowledge to influence your thinking. Catastrophic floods cannot cut a meandering river. You claim it can not because of evidence but because you think that's what the Bible says. But the Bible says nothing about how meandering rivers are created. It's you who are claiming catastrophic floods can cut meandering rivers, not the Bible and not God. You have no evidential, Biblical or divine support for anything you're saying.--Percy