Summations Only

Just a quick note. This is why we recognize both lithostratigraphy and chronostratigraphy in geology. They are not the same things.You didn't know that, did you? And you will never understand it either. All you have is uninformed blather.

Actually, the Kaibab crops out abundantly south of the canyon extending into the Coconino Plateau and south of Flagstaff. It suggests to me that the Kiabab Limestone is the uppermost unit resistant to erosion. The overlying Mesozoic formations are generally less lilthified. Actually not, though the Kaibab does form a regionally erosion-resistant unit. Edited by edge, : No reason given.

Without getting into the mechanics of erosion, it can be simply stated that the rock layers of the canyon have variable strength. The amount of weaker rocks such as the Supai and the Hermit will dictate the average slope of the canyon walls. Some rocks are cliff-formers while weaker ones are slope-forming. If the canyon cut a single rock type the walls would not have that stepped appearance and would be more even.The action of material raveling, sliding and washing and toppling down the slopes is called mass-wasting. This process transports and breaks up the rock mass as it enters the stream channel (even in dry channels). Then when the flash-floods occur or a temporary dam breaks, the boulders are tossed about like toys and transported down the stream.As I might have said here earlier, it is my opinion that uplift does not create mountains ... erosion does that.

It's just a matter of erosion keeping pace with uplift (or exceeding it). I've mentioned this before, but if anyone is interested in what happens when erosion fails to keep up with uplift, just check out Unaweep Canyon. It's a canyon the crosses a mountain range (Uncompahgre Uplift), with small streams flowing in opposite direction, but practically no real river at all. The river that was there could not erode fast enough and was eventually captured by neighboring, fast-eroding streams.

Yes, flat lake and seafloors are pretty common. Actually, I would't say there is a lot of variety here. You can possibly see some darker, harder layers of fresh-water limestone and maybe a little organic layer, but the rest is mostly water-lain volcanic ash, that happens to have varying degrees of oxidation at the time of deposition. These are rocks (though not very lithified), not time periods.Sure they were deposited at different times, but they, themselves are not time periods. Yes, that would be weird.

Why would they have to be 'cleaned off'? It's just an ocean bottom. You don't see a lancscape here because it's the bottom of a body of water. What do you expect? Why not? Sea creatures don't occur everywhere, particularly in a lake that is inundated by volcanic ash from time to time.

The problem is that an advancing sea does disturb the surface before depositing sediments. Please provide a reference. I'm not sure you got that correctly. Besides the Colorado Plateau is an exceptional case of crustal rigidity. This has something to do with a dual crust structure. We can see it in seismic data. Try as you might, this forum is no about you. You are welcome to have any opinion you want and you can express it here as you wish. However, the point of being here is to debate issues. Perhaps you could find some Christian forum where everyone would sit around and nod their heads as you pontificate. In that case your timing is bad and there is no evidence for collapse of the sea floor. Again, your timing is bad. It would seem that the canyon was cut in hard rock and it would take the strongest flows to cut the canyon. You are talking about a waning system that simply doesn't have the time to create meanders and then downcut for a mile depth.

Sure, what's the problem with that? There a plenty of local lacustrine formations and we see them forming today. It's like a hundred other places. These are mere badlands. No, but the Green River Formation covers parts of Wyoming, Utah and Colorado. And that's rather huge example. Edited by edge, : No reason given.

An interesting point here is that the basal sandstone of any transgressive sequence is usually composed of detritus derived from the local bedrock. In other words, the Tapeats is composed of fragments from the Precambrian crystalline rock and the GC Supergroup.If you look at other basal Cambrian sandstones, they also are derived from local bedrock whether you are talking about the Potsdam or the Sawatch or a hundred other equivalent formations.The implication is that the local bedrock is eroded and recycled into the new sedimentary record.

What? This makes no sense at all. Try again. Of course nothing could live in a rock that is lithifying. What are you trying to say? I'm not seeing why. Your post is making no sense at all.

Ah, yes, okay.Well, it still seems a bit watered down. But when Karlstrom refers to 'all the flat layers', that does not include the Vishnu Schist or the GC Supergroup.He also does not discuss anything that happened after the Laramide.

Okay, sure. I have no problem with that. In fact there is fairly recent evidence about how this happened.I was just unsure of the timing. The local uplifts occurred later than Laramide time.The point is that all we know about meandering streams is that they occur in mature landscapes with low gradients, near base level. It would make sense that the meanders were etched into the Kaibab Limestone at that point and that the younger terrestrial deposits were washed away by a long period of meandering stream action; all prior to uplift which would result in downcutting of the canyon within the confines of the meandering pattern. Hence, 'incised meanders'. Edited by edge, : No reason given.

Heh, heh ... soft rocks don't make really good boulders, or 'river rocks', do they? It is wondrous that rocks torn from soft, deeply buried sediments can be carried hundreds of miles and then somehow lithify in shallow stream sediment deposits at the surface. I'll have to do some research into that...

The only reason that the Coconino Plateau exists is because the Grand Canyon cuts the Kaibab Uplilft into two parts.

Basically correct. However, sometimes, the accumulation of sediment is entirely biological. There are coal beds in Wyoming up to 80 feet thick. And that is after a lot of compaction.Subsidence is nice, but it is also possible to have a rise in sea level keeping pace with deposition. In the cyclothems of the Appalachians, there are a large number of minor transgressions and regressions that show a long period of time where the interface between marine and terrestrial is unstable, just moving back and forth as the swamps disappear and reappear or moved inland and than back toward the sea.As you indicate, streams flow across the swampy areas resulting in sand bars and overbank mudstones that add to the diversity of rocks in the section. Once again all of these things are not just observed in the geological record, but in modern environments.