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Faith  Suspended Member (Idle past 1444 days) Posts: 35298 From: Nevada, USA Joined: |
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Author | Topic: Evidence that the Great Unconformity did not Form Before the Strata above it | |||||||||||||||||||||||
ThinAirDesigns Member (Idle past 2373 days) Posts: 564 Joined: |
Faith writes: And again, get your surface as flat as you can, does the rain stop? Does the wind stop? If not they are going to continue to cut into the surface and unsettle its flatness. And as further evidence that your position in absolute nonsense, those of us who have regularly used the lake beds of the west actually rely on the wind and rain to 'reset' the surface every year. Due to people getting caught on the surface in summer thunderstorms, ruts abound by the end of the year.
We rely on the wind and water of the winter to smooth out the surface for another year of high speed fun.
What resets this surface from spiky and rough to smooth and flat? Erosion.
Wind and rain do NOT continue to cut into a flat surface and unsettle it's flatness. Just the opposite is demonstrably true year after year. JB
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edge Member (Idle past 1705 days) Posts: 4696 From: Colorado, USA Joined: |
Far as I know images of how rock erodes aren't available.
So images in Message 312 and Message 284 are not eroded? Not a clue?
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Faith  Suspended Member (Idle past 1444 days) Posts: 35298 From: Nevada, USA Joined: |
So you think the basement rocks of the G.U. were once like the Great Salt Lake? And all that schist and/or tilted strata was buried beneath the surface?
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jar Member (Idle past 393 days) Posts: 34026 From: Texas!! Joined: |
Faith writes: You are never going to get such perfect flatness that there won't be some differences in elevation to get erosion started, even if only inches. As I already said:
quote: Yes, the process continues as long as there is an elevation difference. That is clearly shown by the Great Unconformity. There, over two miles of material was eroded away, the land subsided and became a sea, coarse sand stone was eroded from elsewhere and deposited as the Tapeats Sandstone, additional layers were added over time and the whole area later raised to its current elevation.Anyone so limited that they can only spell a word one way is severely handicapped!
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ThinAirDesigns Member (Idle past 2373 days) Posts: 564 Joined: |
Faith writes: So you think the basement rocks of the G.U. were once like the Great Salt Lake? And all that schist and/or tilted strata was buried beneath the surface? Faith, what I think is exactly what I wrote. You made several assertions that were demonstrably false. I demonstrated how false they were through evidence. That's what I think. JB
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edge Member (Idle past 1705 days) Posts: 4696 From: Colorado, USA Joined: |
So you think the basement rocks of the G.U. were once like the Great Salt Lake? And all that schist and/or tilted strata was buried beneath the surface?
Personally, I think it looked like this Message 257, but you haven't really told me if the surface is smooth or rough in that picture. And then, there is Message 281 which you have not yet addressed.
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edge Member (Idle past 1705 days) Posts: 4696 From: Colorado, USA Joined: |
A question for Faith.
So, are all unconformities prior to the modern one non-erosional?
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edge Member (Idle past 1705 days) Posts: 4696 From: Colorado, USA Joined: |
"Flatter" is not as remarkably flat as the GU in the images I posted in 213 and 313. And again, get your surface as flat as you can, does the rain stop? Does the wind stop? If not they are going to continue to cut into the surface and unsettle its flatness.
Not really. If your understanding were correct we could just erode right down into the mantle. The problem you have is that you cannot erode beyond the base level (usually sea level). You can only erode from the areas above that.
ABE: And didn't any tectonic events occur to raise the land either?
Why should uplift occur at any particular time?
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edge Member (Idle past 1705 days) Posts: 4696 From: Colorado, USA Joined: |
Since we are talking about erosion and the formation of 'flat' platforms, here is one mechanism:
There should be enough notation here to help with the explanation, but if not let's discuss rather than complain. I think this is an important mechnism for the Great Unconformity becuase you can easily imagine it happening as the Cambrian transgression cut into Precambrian rocks on the continent. I have personally seen this on the west coast of N.A., and many of the images we have provided show this mechanism at work.
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Minnemooseus Member Posts: 3941 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: Member Rating: 10.0 |
So, here's the diagram from Faith's original post.
Faith, how flat is the Great Unconformity? 1) I think you may be reading too much into a diagram that is (hopefully) a rough approximation of reality. 2) What that diagram does show, is that the Great Unconformity (nonconfromity) has itself been tilted and faulted after the deposition of the preCambrian sediments. You are getting a departure from (more or less) flatness and horizontality because of tectonic deformation. Moose
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Faith  Suspended Member (Idle past 1444 days) Posts: 35298 From: Nevada, USA Joined: |
more pictures of rock eroding
Let me know when it's eroded down to a surface as level and straight as those I've illustrated of the G.U.
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Faith  Suspended Member (Idle past 1444 days) Posts: 35298 From: Nevada, USA Joined: |
I don't see how that process would get you such level straight contacts as seen in the pictures I've posted. Even in your diagram the resultant platform is not level.
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jar Member (Idle past 393 days) Posts: 34026 From: Texas!! Joined: |
Actually all your pictures show surfaces that are as flat and smooth as the surface at the Great Unconformity.
It ain't that smooth. But if you have been following along in this thread beginning at Message 4 you can get an estimate of just how long it took to get things as smooth as seen at the Great Unconformity and that took something over a billion years. And that is your problem Faith, the evidence is there and all the evidence says that the process of erosion moves material from high spots to low spots and that to do so takes lots of time. That is why Young Earth has been DeadOnArrival for over 200 years now.Anyone so limited that they can only spell a word one way is severely handicapped!
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edge Member (Idle past 1705 days) Posts: 4696 From: Colorado, USA Joined: |
I don't see how that process would get you such level straight contacts as seen in the pictures I've posted. Even in your diagram the resultant platform is not level.
So you assert. How can you tell? I think you are saying that it is not horizontal, but how do you know that the G.U. was horizontal? Certainly the lower sequence it tilted in many places, so what's to keep the unconformity itself horizontal? Besides, we've given you plenty of examples that are pretty clear as to how they happened. So, what have you got? Do you think this surface was level? And do you think it is smooth?
Edited by edge, : No reason given.
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Faith  Suspended Member (Idle past 1444 days) Posts: 35298 From: Nevada, USA Joined: |
Siccar Point is not a useful example when we are talking about the surface of the lower formation without the upper having been deposited. For one thing it's been subjected to such severe weathering there's no way to be sure what it looked like originally.
But I would expect that when it was first formed that surface would have been level, yes. And I figure that was the case because the upper strata, even in their ruined condition, show that THEY were straight. They aren't shaped to fit into dips in the lower strata.
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