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

I think this is implicit in my discussions, but if not, more clarification might help. Perhaps my latest post, Message 494, will clarify some things.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

Are the boundaries between the sedimentary layers considered to be unconformities?The change to deposition of a completly different rock type; sandstone to limestone to shale, etc. must represent gaps in deposition and changes in depositional environments, rather than continuous deposition.

No. Check "Walther's Law." No need for gaps between sediments.

I think I am clear on the general mechanism you have in mind for forming an unconformity, but I don't think that addresses the concern that you seem to be suggesting that erosion today can affect the surface of the unconformity. Maybe that is not what you have meant to suggest, but I don't think I am the only one who got that impression.HBD

But I have offered explanations for all that.

• Evidence for Flood is strata plus fossils.
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• Tectonic activity not caused by Flood but both a part of the catastrophic upheaval of the planet at the time. Volcanism also began at that time: Volcanically active Atlantic ridge is where the Americas split from Europe and Africa.
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• Siccar Point more exposed to weathering than Grand Canyon unconformities which are mostly buried or protected in canyons but also the coast of Scotland gets severe sea weather.
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• There is evidence of slippage in the disturbed or eroded region at some exposures of the G.U. such as where the quartzite boulder from the Supergroup ended up embedded in the Tapeats sandstone.
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• An enormous amount of rubble got washed down the canyon in the receding phase of the Flood. Some probably ended up scattered across southern California, the rest disappearing into the Gulf of California. But the GC is huge and so is the area around it, no lack of areas where it could have been relocated.
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• OR how the parts of the Super Group that still exist could get laid down if not before the Tapeats Sandstone was laid down
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  Not sure what this means, but the strata of the Supergroup would have been laid down horizontally followed in order by the Tapeats and the whole stack from there on up, after which, as the Flood was receding, tectonic pressure forced the Supergroup into a tilt and upward against the Tapeats, where it slid for some distance (the quartzite boulder is a quarter mile from its point of origin), all during the uplifting of the whole area into the Kaibab Uplift. Massive breaking up and erosion of uppermost strata follows, carving the Grand Staircase, and an enormous volume of water carrying broken-up strata is washed into cracks, carving out the Grand Canyon.

You may have objections to all this but I have dealt with all your questions and the scenario is consistent and comprehensive.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

If that surface is exposed, of course erosion can affect it. Siccar Point has very little left of what must have been its original rock, and the more it lost of the upper rock the more any remaining surface of the lower rock would have been exposed.

Another thing to point out is that when we look at the eroded faces inside those ditches they show the parallel (pseudo)horizontal lines that Faith keeps harping about ... and you can keep eroding the faces back into the hillside and they will continue to show "flat" beds of sediment ... until you cut down into older layers with a different geological history.When you only look at one plane section through the sedimentation you miss the information in the orthogonal direction.Enjoy

Well, actually Faith, no you haven't and it seems you simply have no clue what the words explanation, model, method, mechanism, process, procedure or evidence mean. No Faith, that is not evidence of a flood. It seems you simply have no clue what the words explanation, model, method, mechanism, process, procedure or evidence mean.All you have is an unsupported assertion and in fact an unsupported assertion that has been proven to be false for over two centuries.What you need is to explain how your magic flood could sort fossils as seen in reality or produce over six million alternating layers of fine then coarser material or as in the case of the Great Unconformity create a layer of super fine material and then place a layer of coarser sand stone over it or ...(fill in any of the millions of examples that refute your assertion). Again, that is simply another unsupported assertion that has been proven to be false for hundreds of years.The reality is that there is NO evidence connecting such things to any flood or any support (Biblical or otherwise) for any such catastrophic activity beginning at that time.The Atlantic rift is certainly not the earliest example of continental crust movement and all of the evidence shows it began and has been going on for at least 180 million years.Instead of just spouting nonsense an explanation would provide the evidence that the Atlantic rift is only several thousand years old or that the separation of the continents took place several thousand years ago as well as a model to explain how such magic happened. Again, just unsupported assertion. What you need is some evidence to explain how what is seen differs. Look at the canyons cut to make the Grand Canyon, the flash floods, the temperature extremes and show exactly why conditions at Siccar point are worse. Measurements Faith. Provide fact not speculation. Again Faith, stop just spouting whatever pops in your head. How is that evidence of slippage? What is the mechanism and how did it work? More simply stupid irrelevant bullshit Faith.What is the process for your flood selectively washing away over two vertical miles of rock and remember, if you want use the flood receding to remover part of the Super Group (a totally absurd notion to start with) you cannot use it to bring in material to create the layers above the Super Group.Of course you still have never explained how rain for only 40 days and 40 nights could erode anything that was not already eroded to start with. Again Faith, that is certainly not an explanation of anything.How did your magic flood lay down anything and in the actual order seen in reality. How did it lay down fine layers and the coarse layers and the limestone and how does your magic flood create the material to make sandstone or shale or mudstone or limestone or granite? No faith, again maybe it is just that you do not understand the words consistent and comprehensive. What you present is not consistent, not consistent with what a flood does or with what the evidence shows or even consistent throughout your assertions.It certainly is far from comprehensive since you never touch on how your model, mechanism, method, process, procedure actually does anything. How does your magic flood wear rock differently that annual monsoons or waterfalls? How does you magic flood deposit materials with coarser layers above finer layers?Details Faith. Explain how the magic worked.

I was hoping for a more detailed answer from someone who knows something about Geology.

Perhaps edge will come back and help you out.

Please let the discussion be about the topic rather than assessments of the quality of others' contributions.

Just trying to see if I could identify what is inhibiting discussion and suggest possible ways to improve the discussion.

I don't think that image is intended to depict the different layers to be separated by unconformities. The red and black lines only. You have to think of this in terms of geological time. The change will not be so abrupt but rather the layers will blend into each other at the boundary. In order to prevent mixing of layers there would need to be enough time for the lower layer to consolidate otherwise it would just be stirred back up when the next layer is put down.So if you think about it, there could be a couple hundred years from when one sediment deposition stops and another begins, but that would be merely a blip in geological time and probably wouldn't show up in the rock record.Faith was right that Walther's Law would be applicable for at least one way sedimentation environments can change, as it could vary both spatially AND temporally.HBD

Yea, what are the blue stones?
_________________Percy posted this image at Message 487It can be very hard to interpret an 2D image and draw conclusions about 3D reality, but it looks like the contact dips in the lower left. What ya think?I am not sure what to make of the area in the blue circle.HBD

Thanks for answering. Yeah, I wasn't thinking about your illustration specifically.I have been thinking about this through the whole discussion and comparing all the outcroppings and exposures I visited and photographed during road trips in the American Southwest the last 2 years. I think I drove my grandson crazy, stopping every few miles to shoot photos of cliffs.Some of the boundaries between layers are clearly unconformities because there is evidence of erosion on the lower layer and filled-in streams or sand dunes.The angled strata below the Great Unconformity makes its location and appearance pretty striking. I started thinking about some of the other places where I had seen quite distinct boundaries between layers on exposed cliff faces and wondering if a lot of them might be considered unconformities because there would have to be significant periods when there was no deposition.Before this discussion, I thought unconformities were where tilted strata meet horizontal strata. Now I realize that they are really gaps in deposition and that they represent time, sometimes a lot of time. I understand the concept of Walther's Law and how if sea level rises various depositional environments will move in relation to the change in shoreline.My understanding is that Walther's Law is about a specific depositional situation and does not account for all sedimentary layers everywhere.