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

Yeah, no expert but I did just spend much of the day researching this thing that Faith throws out seemingly to answer so many different sedimentary questions raised. I'm pretty damn sure it's not the magic bullet that she imagines.JB

Heh, heh,...That was the one question I was afraid of. I'll try to check it out. They look very like azurite, but that wouldn't quite fit the environment of deposition. I'm pretty sure that's the case. I think it's a flat area with some pebbles laying on the surface, but you're right, it's hard to tell. There's nothing like actually being there to interpret geological features. What I'd really like to see is a view from the right looking at the scarp face. That would give some idea of the third dimension.

The other contacts are not important to the point I was making, but I probably should have made that clearer. Many times there are knife-edge contacts between rock types, but what also happens is there is what we call a gradational contact where rock types will switch back and forth for a while. This is exactly right. I could make the argument that every bedding plane is a brief disconformity or paraconformity. But usually, such periods of time cannot be resolved in the record anyway.

See Depositional Models of Sea Transgressions/Regressions - Walther's Lawand I applied the graphic in Message 9 to Grand Canyon in Message 39 and Message 40 to show how changing sea levels explain the different depositional layers in the Grand Canyon.Enjoy

One important point in what you are discussing is "sea level changes", not a series of waves or a flood but rather long term transgression and regression events separated by relatively static periods.

Of course. RAZD doesn't believe in the Flood. Nor does Moose, who agreed on that same thread that Walther's Law can account for the strata in the GC.And I'm also talking about a long term transgression and regression and certainly not "waves," only I think the model covers the Flood timing of one months-long transgression followed by a couple months at its maximum height, followed by a months-long regression. There's no reason the principle wouldn't apply to this model.Edited by Faith, : No reason given.

She got pretty excited when she first heard about it. It became her magic method of explaining how her mythical flood deposited all the sedimentary layers in the world. She will go to extraordinary lengths to shoehorn her flood explanation into Geology and ignoring libraries full of evidence that demonstrate she is wrong.The cool part though, is that we all end up learning a bunch of neat stuff from people like edge, RAZD, Dr. A, Roxrkool and a bunch of others.

Again Faith, that is not a model until you can explain how your one month magic can create the materials that got deposited during each incident and why there are more than three magic incidents and how the material was created before being eroded, moved and deposited during your magic flood stuff.The reason your model doesn't apply is that it is not a model but rather just "insert magic miracle here".

Well then you should have said AMAEABS (Ask Me Anything Except About the Blue Stones) Thanks Mr. obvious, LOL. I was saying it is unclear if it is above the unconformity or obscuring it. No doubt about that. That would really help. Pictures seem to be taken mostly by sightseers not people involved in an internet discussion about unconformities. Not much help there.HBD

Edge posted this picture in Message 453 as if it proves something, but to me it's completely undecipherable, so if posslble I'd like to see some discussion of it to clarify what it's supposed to represent. I looked up Mosaic Canyon and didn't find this formation. The angle of the photograph may be the problem but to me it looks like some very battered lengths of rock lying flat on the ground, and the ground is that cross-bedded sand. The sand looks from this angle to be completely unrelated to the "stepped unconformity" edge says the lengths of rock represent.He says the [abe; stepped ends of the /abe] rock (dolomite) shows no weathering from a smooth surface. I have no idea how one could tell that from this photo. To my eye it shows a lot of weathering on any surface you look at, surface-schmurface. If it was once strata surely it was originally laid down in flat horizontal layers of the sort we see in the strata. How do you get from that to these desiccated irregular lumps of stone without its having undergone trauma of some sort, possibly including weathering? And how could anyone possibly tell whether the stepped ends were the surface of an unconformity?And no matter how I peer at it I can't see the cross-bedded sandstone as "overlying" the stepped ends of the dolomite.Please explain. Perhaps another angle on the same formation would help?Edited by Faith, : No reason given.

I don't know much about this formation and to be honest, I can't make out crossbedding in that "stream bed" from the photo. A couple quick comments though How could they be "completely unrelated?" when they are touching each other? It is kind of hard to see the contact line with his yellow line in there (maybe he could post the unedited version?) but it does seem clear that those two sediments are not conformable. It makes no sense to say they are "unrelated." Because the two materials that make up the two strata contact each other unconformably. Another very confusing comment. Of course they are strata... Stratum (pl: strata): is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers.Can you distinguish those two sediments from each other? "possibly including weathering" ??? Of course it has been weathered. I can't for the life of me figure out why you would say this? Yes, it possibly includes a LOT of weathering. Because the two strata contact each other unconformably. What is the exact nature of the unconformity? That is not so clear from the picture, but it is an unconformity - by definition.The point of the "rip-up" portion is that it is comprised of material that was derived from the dolomite (the larger clasts) and at least one other material of which the source is not in the picture along with fine sand and gravel. This looks to me like a mass-wasting or possibly scree at the base of a cliff.A broader picture would be helpful, though.HBDABE: Maybe interesting: The relationship between the Neoproterozoic Noonday Dolomite and the Ibex Formation:Edited by herebedragons, : Added link to paper

Here we are arguing about a photograph again...I find it strange that you consistently see something different from everyone else. Yes, there is no evidence that the unconformity surface was ever flat. If you think it was flat, please tell us why. Partly because there is no disruption of the upper beds and because there is no abrasion or dissolution at the contact. Please explain what this weathering looks like. Of course they were weathered, that would be the nature of an erosional unconformity. They were likely laid down as normal sediments, lithified, tilted and then eroded. What else would they be? I'm sure you don't see it. But that's irrelevant. Why would there be cross bedding? No, it probably wouldn't help. This is what you get. You can deny all you want, but most people see something different. How are you going to make your point by just saying, "I don't see it"?Now, why don't you answer my question?

Thanks for replying. Just one brief comment for now. I don't see any contact at all, I see the rock lying on top of the sand. Yes, maybe the original would show the contact.

Heh, heh... you know, when I first looked at the picture, I didn't even notice the blue colors. Probably because I was so interested in the basal sand and its internal textures, and then the breccia with the very angular clasts and what they might mean.I thought it was pretty clear that the beds are eroded since that's what happens when you take bedded rocks, break them up and transport the fragments away... perhaps even into the next unit above(?). Of course, to Faith that isn't erosion until it occurs in modern times, even though the fragments above look exactly like they came from the underlying dolomite.Then, of course, those clasts are mixed in with other material that was broken off other rocks (erosion?) and transported from somewhere else. How does that occur in Faith's scenario? How does she transport those sediments to their current position if the fine sand is created by abrasion of the dolomite?I mean, it isn't possible to have erosion in the Proterzoic, is it? So it must be something else.

Ummm... that would be a contact... Usually, we highlight the contacts to make them easier to see.Edited by edge, : No reason given.