Evidence that the Great Unconformity did not Form Before the Strata above it

Concerning horizontality, you believe that sand falling uniformly upon a submerged sloped surface would pool at the lowest point as if it were water. A little contemplation about how that could possibly happen should bring you to the same conclusion as everyone else, that such an experiment is as unnecessary as dropping a rock into water to prove it sinks. If loose sand really flowed to the lowest point then all beaches would soon be bare as the sand would flow out into the deep ocean as soon as it was stirred up by a wave.Sand can maintain a steeper angle of repose on land, but it doesn't flow to the lowest point on land either. Here's an image of a very steep street. Do you know what would happen if a dump truck dumped a load of sand in the middle of this street? It would run downhill a few feet and then sit there. Or what if you sprinkled sand very slowly on this street. The grains might rebound a few inches downhill off the hard surface, but they would otherwise just sit there. Or think about it another way. You create a sloped surface of loose sand on the bottom of the aquarium. The sloped surface of loose sand has no trouble maintaining itself. It doesn't flow to the lowest point and form a horizontal surface. It just sits there.Now a grain of sand falls somewhere on the sloped surface and becomes just another grain of sand making up the sloped surface. Why is it any more likely to move toward the lowest point than any of the other grains of sand that were already there?And the same is true of all subsequently falling grains of sand, assuming they're falling uniformly across the sloped surface. Only if all the grains fell in one place and built up a mound would the sand tend to roll off that mound more down the slope than in any other direction.A 50-lb bag of fine playground sand is $3.69 at Home Depot, a cheap aquarium is around $20. A couple people here have made noises that they might be willing to carry out the experiment and post photos. Would you accept such evidence?

Here's a video that includes a sedimentation tank experiment, it's set to begin at just the right time. Skip the sound unless you know Spanish. This is a different experiment than the horizontality experiment I mentioned just previously, but it's extremely instructive nonetheless. It releases sediment suddenly in successive waves, perhaps to simulate storm events or sedimentary epochs, I'm not sure, and it shows how the sediments deposit: Watch the video until the end of the sedimentation tank portion. The final result should look shockingly familiar: No intrusions or tectonic forces necessary.Edited by Admin, : Clarify.

It was fascinating to see sedimentation transport occurring in real time in this video, it starts around 15 seconds in: This shows that sediment transport requires flowing water on a mild slope.

No, it isn't forgotten at all. The entire point of the discussion about horizontality is to get you to accept that layers like those in the road cut can be deposited on slopes. Not really. Concerning horizontality, the question is whether by necessity the layers in those road cuts could only have been originally horizontal when deposited. You're not thinking this through. If you can form one sloped layer atop another sloped layer, then the top of the new sloped layer is just another sloped surface on which another layer can be deposited. "Stick" is the wrong word. For the most part sediment doesn't slide down a slope to the lowest point (unless it's too steep) because of normal everyday friction. What in the world makes you think it could?You've taken an absurd position, and I'm only interacting this much in the thread so that we can get past this and resume discussion of the actual topic. Your message is mostly just a reassertion of your views and still provides no rationale. What makes you think sediments can only deposit horizontally? What is the process you thought through to arrive at this conclusion? There don't really need to be experiments, only a belated realization by you that you have no idea how some incredibly simple and obvious things about the real world really work.Your message gives no indication that you thought at all about the arguments I made about sand not being able to flow down a slope, that if it did beaches would quickly empty of sand. I asked you to think about why any newly deposited grain of sand would have any greater likelihood of sliding down slope than any of the other grains that were already there that it fell next to.So why don't you tell me your thinking about this a little bit. If sand slides down slope to the lowest point, why are there beaches? If sand slides down to the lowest point, what causes the newly deposited grain of sand to move down slope when all the other grains of sand that were already there didn't do so?Edited by Admin, : Grammar.

The video you're referring to was for a different context. Some of the first words you quoted from me in your message were "Concerning horizontality" and "the layers in those road cuts", so presumably you knew that I was talking about sedimentation onto flat submerged terrain, yet now you're presenting as counter-evidence a video of sedimentation falling out of moving water onto a decidedly non-horizontal terrain. Of course sediment is going to collect the most at the lowest point on rolling terrain as sediment bearing water flows across, but long flat (and possibly tilted) terrains in quiet water don't really have low points and don't have a way for sediment to be carried across them.Let me repeat the question. For the most part sediment doesn't slide down a slope to the lowest point (unless it's too steep) because of normal everyday friction. What makes you think it could? Citing the notable but incomplete views of a scientist from 350 years ago is not a "process you thought through." How so? What is the process you thought through to arrive at the conclusion that it's some kind of trickery? What details of how the real world actually behaves are you applying? How do sediments fall out of suspension in a way that tells you non-horizontal deposition is impossible? Please explain how it is a violation of nature. If you find yourself starting to write, "Steno's principles say..." then please back up and try again. As everyone expects. The point of that video had nothing to do with horizontality. It was intended to address your unsupported contention that the Archean layers were intrusions. Then what do you expect to see when the sediments do not "fall down the slope and pool at the bottom?" Where do the sediments go? If they stay where they fall, and if the sedimentation rate is equal across the tilted surface, how could anything else result but a flat layer?--PercyEdited by Admin, : Change author.

In Message 1714 Edge already pointed out that the base of the Tapeats is not even near the monadnocks, and I can add that none of the layers of the Grand Canyon are even or consistent in thickness. The Tapeats varies from 0-400 feet thick. The Bright Angel Shale is 350-500 feet thick. The Muav varies from 350-600 feet thick. And so it goes. All layers of the Grand Canyon vary in thickness.What leads you to think there is any such thing as evenness of deposition everywhere? What are you imagining prevents local conditions from causing great variations in sedimentation rates from one place to another? Aren't the varying thicknesses of the layers of the Grand Canyon precisely what one would expect from variable deposition, not even deposition? With consistent sedimentation rates across the slope, what are you imagining could prevent layers being deposited evenly?

In that case please put your views about the impossibility of non-horizontal deposition on the back burner until such time as you can provide rationale and/or evidence. Just so it doesn't catch you by surprise later on let me say that this means you can't argue for your view that there's a change in the angle of tilt in the layers of the road cut that could only have been caused by sagging of the layers to the left.

Hi Faith,In responding to your post I'm going to make a moderator ruling. I think what HBD is saying is that you're dismissing evidence and arguments out of hand while providing specious counter arguments ("it looks like...", "it just comes off as..."), and that if you're going to continue in this way then there's little point in putting effort into providing even more evidence and arguments to you. HBD provided this image: It has asymmetry reflecting flow. Contrary to your claims of even distribution (paraphrasing, just thin coats with pooling in the depressions), the bottommost layer (it's yellow) does become slightly thinner as it rises up the slope, and on the far side it disappears altogether for a while. The next layer up (it's brown) looks precisely like some layers in the McKee diagram. And the next layer above that (a lighter brown) almost completely pinches out on the far side of the mound.Ideally both sides in a discussion would bow to the evidence and move on, but as that isn't happening here I'm therefore ruling that unless you can present a rationale for your position that has far more substance and far better correspondence to the evidence than "it just comes off as thinly coating the slopes on the way down to pooling in the depressions" that the geological position that the boundary between the Tapeats and Archean is an erosion unconformity, not an intrusion, has succeeded and that discussion should move on.

This doesn't appear to have any correspondence to the video at all. It's like you're looking at something completely different than everyone else, or as if you are unable to see obvious similarities in images. In his reply Edge commented similarly.If you want to pursue the point then you're welcome to argue it again, but some points need significant modification if they're to make sense to anyone. To point out just one example, you say "There is no filling of the low places in the [McKee] drawing," yet everyone else sees the layers thickening the deeper they are in the basins. If you're looking for identicalness between the sedimentation experiment and the McKee drawings then you're not going to find it and should by no means expect it. The experiment was to illustrate general principles of sedimentation, not to replicate what happened in specific regions of the Tapeats boundary with the Great Unconformity. To continue arguing your point you need to make observations that don't cause people to wonder if you're looking at the same images they are, and you need to provide a reasonable rationale for why the sedimentation experiment and the McKee Tapeats diagrams aren't uncannily similar.

It's toward the end of June - let the thread know if you need any last minute assistance or information.

It might be a good idea to list the experiments you plan to perform.

Using clay instead of sand to form the top surface means you can create very steep angles, so it's important that the surface you create from clay is not steeper than the sand's angle-of-repose, so I propose you perform the angle-of-repose experiment first:

1. On a dry level surface of clay let sand fall on a single spot using a small funnel. Measure the angle of the pile of sand that forms.
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2. On a submerged level surface of clay let sand fall on a single spot on the water using a small funnel. Measure the angle of the pile of sand that forms.

Now perform the sloped-surface experiment:

1. Create a mild sloped surface of clay inside the container. The slope should not be steep like this, which is steeper than the angle of repose:
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   It should be no steeper than this (this is the best I can do using characters, the slope itself should of course be smooth), and you must make sure that it is not steeper than the submerged angle-of-repose:
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2. Once you have a mild sloped surface of clay, add water to the container so it covers the clay to a depth of about an inch at the most shallow point.
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3. Sprinkle sand slowly and evenly across the surface. A colander, strainer or some other kitchen utensil might be helpful, you'll have to play around with it.

Edited by Admin, : Improve the instructions.

Apologies if the advice was too elementary, but it is because you *don't* know what you are doing (as demonstrated by the fact that you that actually have to perform these experiments just to demonstrate to yourself the most elementary and intuitively obvious facts of the real world) that I wanted to make sure you that both you and the people you're debating with agree about which experiments are most relevant to the discussion, and how they should be carried out so that both sides can agree about what the outcome means.

I'm concerned about your use of the phrase "superficial way." It is important to insure before you perform them that the experiments you're performing are not, in your view, a "superficial way," and that you'll accept the outcome, whatever it may be.

I'm trying to insure that this thread in which so many have invested so much can resume discussion of the topic by making sure you're able to assure yourself of the way sediments are really deposited.It shouldn't even be necessary for anyone to have to do the "sedimentation on a slope" experiment to understand that sediments accumulate on slopes. A simple thought experiment should suffice. Imagine a few grains of sand falling on a submerged sloped surface. How are those grains of sand going to slide down the slope? After all, sand is gritty. Unless the submerged surface is already steeper than the angle of repose, those grains will stay there. If that weren't true there could never be any hills of sand, not in the desert and not under the sea. There wouldn't even be any such thing as an angle of repose - all collections of sand everywhere would be level, and sand would behave like water.But please, do the experiment anyway.