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

You are confusing dropstones with the archaean rocks in McKee's diagrams.

Not really. I am comparing the draped sediments over a dropstone to draped sediments over an Archean topographic high point.

Sorry for confusing the discussion. I meant to type drag folds, I thought I typed drag folds. Apologies.

I've been looking for one of these for a while now and came across a picture today. They can be had at a lot of science toy stores and gift shops. I guess most of them are water immersed, but there may be some in air. At any rate, they are a good demonstration of cross-bedding and show how eosional surfaces might form in transported sand deposits.ABE: Just to clarify what this is, basically, it is two panes of glass in a frame with several different colored sands poured in between the panes. The angle of repose is clearly shown by the different streaks within the gray and the brown sectors. The boundary between the brown and gray is some kind of hiatus in deposition. I think someone tipped the apparatus after the gray sand was deposited. Edited by edge, : No reason given.

Just in case anyone is interested, I tracked down a few links to images showing non-horizontal deposition of sediments and some drape features in sedimentary rocks.The first one shows a seismic image of sagged or draped sediments within a filled stream channel. There is no evidence of faulting having created the channel. The channel sediments thicken and sag toward the middle of the channel.The red line and arrow are intended to show where gold would be concentrated in the base of the channel. The image is a cross-section of the channel and the old stream would be flowing either toward or away from the viewer. This one shows a small channel with concave upward bedding planes cut into horizontal bedding and, in turn, overlain by more horizontal beds. I would liken this to some of the sagging sediments that Faith has repeatedly referred to as fault- (or shear-) related in some way. The red line was in the original and appears to show another channel cut higher in the section.Again this is a cross-section of similar orientation to the seismic image above. I can annotate if it is not clear to everyone.

Why are faulting or deposition the only two options? Couldn't soft sediment sag by stretching without faulting?

Soft sediment deformation is common. Stretching would have a particular appearance (particularly if the strata were plastic) and I haven't seen it in these cases. If you have some evidence for stretching, you should present itThe point here is that you are the one who wanted faulting. You claimed that shearing occurred along the unconformity and that the 'monadnocks' were uplifted, 'intruding' the sediments.It appears that deposition is the only real alternative. Compaction of sediments would contribute, but that isn't your scenario. And I'm not even counting the other contravening evidence to your 'one deformation/igneous event' story.

It actually looks stretched to me in the photo. If it was the channel for water it seems likely the water would cause it to sag. You imposed the whole idea of faulting on me, and I didn't mention shearing in relation to the monadnocks, just those particular cases of the great unconformity where it is the only explanation for such a level flat surface that I can think of. You added the faulting because that is what you expect to see with shearing and I have to suppose you do, but then you're imputing to me something I didn't say. As for the monadnocks I don't recall using the term. I was focused on the "draped" sandstone around them which look like what you call "drag folds" so I used that term. You added the "shearing" and the "faulting" and again I'm sure that's in keeping with what you've observed but again it does put words in my mouth and then you start demanding that I account for those concepts when I didn't use them. Yes, I understand the sequence but it's still unfair.As for the "drag folds" since they represent strain on the layers isn't there a point where they've merely stretched but not faulted? You are not being very clear. And it's tectonic event, not just igneous.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

What does one do with that sandbox? Shake it up and see how it sorts itself out or what?

Usually, one just rotates the box. In this case, I think the sand was poured in from the top.

Remember, 'looks like' is not evidence. Evidence would be something called boudinage; or maybe cleavage, or some kind of micro-fracture or fault. Actually, dewatering would do that. That would happen with compaction. However, the coarse beds don't compact very much Faith, the monadnocks form the unconformity surface.You also said that they were uplifted or intruded. But you were never clear on how that happened. How will you do that without faults? Faith, we are almost never sure of what you are saying. I know of no way to 'intrude' the schist into the Tapeats without some kind of faulting. If you have another mechanism, it would be good to tell us about it. But they are not drag folds ... as has been demonstrated. The problem is that you speak with such authority about things of which you have no knowledge. The things you say make no sense. If you have drag folds, then there must be some kind of fault. Where is it? They can be folded prior to faulting, but I don't think it's necessary. Not sure what you mean by 'stretching'. That's what I meant by 'deformation'. And I'm not clear about what? Just ask.

I'm not offering evidence, Edge, all I said was it looks stretched to me. If it doesn't to you, fine. OK. BUT NOT THE STRAIGHT FLAT SURFACE OF THE GU in the pictures I put up early in the thread, and I've never confused the two although you keep insisting that I do. I don't know, edge, it's my theory, OK? When I have some evidence I'll let you know. Like I said, when I know I'll tell you. I must have missed the demonstration. Why MUST there be? Is there never a drag fold that just dragged and didn't fault? Dragged almost to the point of faulting but not all the way to that point. I really don't want to get back into this whole argument, sorry I answered you. Have it your way. I'll keep my thoughts to myself until I have some Evidence of the sort you want.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

So, how did the Great Unconformity occur? Some places it's level and in some places it's not. We have given you explanations. Just because you cannot envision a mechanism for level surfaces isn't quite enough to convince anyone. It appears to most of us that it's whatever you want it to be at any given place. Well, if you can't tell us, we have to guess, don't we? Percy showed you what drag folds look like. Sure. It's called a 'fold'. Well, seeing that we are mostly 'evidence centered' here, that might be a good idea. I can see that this is pretty frustrating for you.

I wonder if it wouldn't be possible to reach a better understanding on this point. You say that the layers in the concave bedding circled area look stretched to you: You're saying that you see some quality in the circled layers that makes them appear that they've been stretched, something that is missing from the other layers in this image that are not stretched. Can you describe what that is?Also, if the layers did drape and sag and stretch down from above into a depression, then it raises the question of where the layers came from. They didn't come from the layers immediately above, because those layers are intact. And they didn't come from the layers immediately adjacent left and right because those layers butt up against the concave beds and are not continuous with them. Could you describe what you see as the origin of those layers.Also, can you describe how the empty depression that the layers supposedly sagged and stretched down into was formed? Ideas arrived at without evidence are not theories. Revelation more accurately describes ideas derived from the Bible. You have some ideas based upon revelation, and now you're seeking evidence to support those ideas. You're well within your rights to say when you have no evidence for an idea, but not only is that lack fatal, something you seem charmingly and completely oblivious to, you also seem to forget that many different ideas of the world's origins have been derived from revelation. And the one quality all these ideas share is a lack of evidence.So as I said I think you're well within your rights to just state when you have no evidence, but that means its time to put the claim on the back burner until you do have evidence. Please don't press on with claims that are without evidence. Edge will have to correct me if I'm wrong, but I believe this is a definitional issue. By definition a drag fold is one that occurs as a result of movement along a fault line. When Edge says the fault may not be visible in a particular diagram or image he isn't saying that there is no fault, but only that it isn't visible. If there were no fault then it couldn't be a drag fold.So when you say that the concave bedding planes in diagrams like these are drag folds: Then if they're drag folds there have to be faults somewhere, otherwise they're not drag folds. So where are the faults? As Edge says, it's always possible that from a particular angle or crosscut that a fault might not be apparent, but it still has to be there somewhere. So if in your view the faults aren't visible in this diagram then it would be very helpful if you could describe where you think they are, because to everyone else it doesn't seem possible. If it helps, here again is that image of an actual drag fold:

An important point here is that these sediments are not very lithified. I'm not sure how they can be stretched. These are important questions. Most of us have the ready explanation that the depression was caused by erosion and then filled by stream sediments. The term 'drag fold' is very descriptive. When you 'drag' something across a surface, you are emulating a fault plane.Having said that, a fault can start out as a fold. At a certain strain limit, the rocks being folded will rupture and a fault is formed. However, folding is not a necessity. The point is that to call something a 'drag fold' you should have some kind of fault plane present. I would call them drape folds, if I called them folds at all.