|
Register | Sign In |
|
QuickSearch
Thread ▼ Details |
Faith  Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: |
|
Thread Info
|
|
|
Author | Topic: Evidence that the Great Unconformity did not Form Before the Strata above it | ||||||||||||||||||||||||||||||||||||||||||||||||
dwise1 Member Posts: 5949 Joined: Member Rating: 5.5
|
Actually, that was precisely my point. Faith was accusing all of us of not doing what we actually do all the time, while claiming that she does what she has never done: hypothetical thinking.
Her most glaring omission is the total lack of testing her guesses. But, being the nice helpful people that we are we all do that testing for her. And she always reviles us for it. But even more insidious is her other omission, the lack of any knowledge of physics or of geology which causes all her guesses to be complete rubbish to begin with. Without that knowledge and understanding, her "hypotheses" (in quotes because they cannot begin to approach the loft status of real hypotheses) cannot hope to ever have any bearing on reality except through pure accident. And it is not just that she is so incredibly ignorant. She has repeatedly and explicitly refused to even consider learning anything about geology or physics. As a result, all that she can come up with is sheer nonsense. So, she falsely claims to engage in hypothetical reasoning whereas she has no clue what that even is or entails. And she accuses us of being incapable of hypothetical reasoning whereas in reality we do it all the time. It would be such a wonderful change if Faith were to learn how to engage in hypothetical reasoning. Sadly, that will never happen.
|
||||||||||||||||||||||||||||||||||||||||||||||||
edge Member (Idle past 1728 days) Posts: 4696 From: Colorado, USA Joined: |
This is an interesting example. If you look at the area just below the label "Potsdam Sandstone" it has clearly been deformed. It has a different "texture" than the rest of the rock face, probably caused by fracturing due to pressure from beneath.
What you are saying here is that there are two obvious deformational events, of very different character and degrees of strain. There is no way to place both of these events into the same time/space frame unless you've got remarkable degree of displacement along the contact (the unconformity). We do not see this.
I agree that an uplift occurred after the Potsdam Sandstone was deposited.
|
||||||||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1427 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Of course I mean what if you're wrong, and that really it's the Bible that tells the truth about the world and that scientific evidence must be false where it contradicts it? What it would mean is that all evidence is illusion and trickery, designed to fool people by a joker god. Including the bible. That is the logical result if you don't assume that all evidence is objective empirical evidence of reality, as science assumes, and then uses to test explanations of reality. Enjoy. Edited by RAZD, : pick oneby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
|
||||||||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1427 days) Posts: 20714 From: the other end of the sidewalk Joined: |
Your conjecture:
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 the EVIDENCE which shows your conjecture to be nonsense: Nice. Utah salt flats? Part of the problem is that normally sections we view are made by rivers cutting them, and so the sections are parallel to the river\valley, and Faith thinks that you should see the cross-section of the erosion pattern instead. by our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
|
||||||||||||||||||||||||||||||||||||||||||||||||
RAZD Member (Idle past 1427 days) Posts: 20714 From: the other end of the sidewalk Joined: |
... But if you break the rock to look at an unweathered surface, the actual color of the material is a rather boring gray. ... What? It doesn't look weathered by millions of years??? /sarcasm Of course geologists have the advantage of being able to look at unweathered rock from fresh breaks (one of the reasons they carry those cool hammers) while pictures only show weathered surfaces, which only occurs after the rocks are exposed ...
I got to use one to dig out some trilobites in Ohio during a high school field trip (which was a little difficult if I don't believe in Ohio) Enjoyby our ability to understand Rebel☮American☆Zen☯Deist ... to learn ... to think ... to live ... to laugh ... to share. Join the effort to solve medical problems, AIDS/HIV, Cancer and more with Team EvC! (click)
|
||||||||||||||||||||||||||||||||||||||||||||||||
ThinAirDesigns Member (Idle past 2395 days) Posts: 564 Joined:
|
RAZD writes: Nice. Utah salt flats? Those where actually El Mirage dry lake bed in California, but the exact same sequence happens on the salt flats year after year (or doesn't, according to Faith). The view of erosion is such a scale issue. Faith is making the mistake of zooming WAY in and looking at only a tiny portion of the erosion process. If one were to zoom into an extremely close view of those ruts in that lake bed during a rain, one would indeed see rivers cutting through the 'mountains' and depositing silt in the valleys. If one zooms out on earth to a satellite view, on can easily see the lake bed and the whole earth process are exactly the same. JB
|
||||||||||||||||||||||||||||||||||||||||||||||||
herebedragons Member (Idle past 879 days) Posts: 1517 From: Michigan Joined: |
I am not sure two tectonic events is clear to me.
I see an erosional surface of gneiss. The tan unit of sandstone was laid down and tapered off into a high spot in the gneiss. The grey sandstone was laid down over that. The gneiss in the center of the image buckled upward and crushed the sandstone in that center section.
It looks like the right side of the image was lifted slightly, but that could have happened at the same time as the center deformation. Other than the obvious tectonic forces that would have shaped the gneiss in the first place, what other tectonic event do you see in the image? HBDWhoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca "Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem. Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.
|
||||||||||||||||||||||||||||||||||||||||||||||||
herebedragons Member (Idle past 879 days) Posts: 1517 From: Michigan Joined:
|
Nevertheless, as you point out, the layers are 'draped', but what you miss is that they also thin toward the higher point of the gneiss. I think this is another point that is not well understood because the Principal of Horizontality suggests that all sediment is laid down perfectly horizontally. Sediment is not laid down perfectly horizontal, but can be draped over an obstacle or [whatever you would call the opposite effect] in a basin.
Michigan Basin as an example... thin towards the edges, thick in the deeper sections. HBDWhoever calls me ignorant shares my own opinion. Sorrowfully and tacitly I recognize my ignorance, when I consider how much I lack of what my mind in its craving for knowledge is sighing for... I console myself with the consideration that this belongs to our common nature. - Francesco Petrarca "Nothing is easier than to persuade people who want to be persuaded and already believe." - another Petrarca gem. Ignorance is a most formidable opponent rivaled only by arrogance; but when the two join forces, one is all but invincible.
|
||||||||||||||||||||||||||||||||||||||||||||||||
edge Member (Idle past 1728 days) Posts: 4696 From: Colorado, USA Joined: |
I am not sure two tectonic events is clear to me.
I was being a little bit liberal in my definition of 'deformation' in this case. However, I'm assuming that the gneiss was deformed early, resulting in a metamorphic rock. To me that is pretty clear.I see an erosional surface of gneiss. The tan unit of sandstone was laid down and tapered off into a high spot in the gneiss. The grey sandstone was laid down over that. The gneiss in the center of the image buckled upward and crushed the sandstone in that center section. It looks like the right side of the image was lifted slightly, but that could have happened at the same time as the center deformation. Other than the obvious tectonic forces that would have shaped the gneiss in the first place, what other tectonic event do you see in the image? Where we get into the 'uplifted' center of the photograph could possibly be deformational, but it's pretty weak. But whether deformed, or just erosion/deposition, there is definitely something happening that contradicts Faith's scenario. My opinion: it's just a 'drape fold' over a topographic high in the basement rock. It's most likely just depositional. Again, we are hampered by not being on-site.
|
||||||||||||||||||||||||||||||||||||||||||||||||
edge Member (Idle past 1728 days) Posts: 4696 From: Colorado, USA Joined: |
I think this is another point that is not well understood because the Principal of Horizontality suggests that all sediment is laid down perfectly horizontally. Sediment is not laid down perfectly horizontal, but can be draped over an obstacle or [whatever you would call the opposite effect] in a basin.
Exactly correct. What you see on a large scale, such as in the Michigan Basin, you can also see in a local context such as in the figures from McKee that you showed earlier. Michigan Basin as an example... thin towards the edges, thick in the deeper sections. I think Faith has referred to this effect in some ways, but it has been hard for me to tell what she was getting at. The problem is that this is a normal and well-understood phenomenon.
|
||||||||||||||||||||||||||||||||||||||||||||||||
Faith  Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: |
But here you've given me even better evidence that the GU did not form before the strata above were deposited.
But this statement suggests you still don't understand what an unconformity is. An unconcormity is a boundary between two layers that displays evidence that deposition was not continuous. Tectonic uplift does not transform a conformable boundary into an unconformable boundary. But you do not have evidence that deposition was not continuous in this formation, or those I posted earlier either, \that show the straight level contacts, because your evidence is the erosive surface and the difference between the rocks above and below. In the earlier pictures I posted nobody could find an erosive surface straight and level enough to demonstrate that it's even possible, while my view that abrasion could account for it adequately explains it. I couldn't care less if it has what you think should be the marks of abrasion or not, it's the only explanation that fits the facts. And in this current example the collapse of the strata into the "erosive surface" instead of filling in its irregularities proves the strata were already in place on a straight and level surface until that surface was disturbed, no doubt by tectonic activity. How do I know it was straight and level? Because the sagging strata ARE strata, originally straight and level strata which originally deposit horizontally, which could not have that form if they hadn't had a straight and level surface under it. So in this case, and the others in a different way, tectonic uplift DID "transform a conformable boundary into an unconformable boundary." Your pedantic definitional assertions notwithstanding, that's what the EVIDENCE here shows. These angular unconformities I've used as examples WERE formed by continuous deposition and THEN a boundary was made unconformable after they were all in place. They were never unconformities at all by your definition, that's just a misinterpretation by Geology. That's what the EVIDENCE shows.
Look at the boundary between the gray unit of sandstone and the tan unit. Why did it not change to an unconformity due to the uplift? Why just the boundary below the tan unit? Due perhaps to my eye problems I don't see the color distinction you are referring to anywhere but between the "Precambrian Gneiss" and the strata above it, which is where the "unconformity" is. But I've explained many times why I think such a boundary probably occurs at a particular level in a stack of strata, which is that it's a point in the stack where there is a difference between the kinds of rock, so that there is enough textural difference to separate them more easily than at contacts between layers of the same kind of rock; PLUS the fact that it's the point where the weight of the stack above is just enough to resist the force of the tectonic uplift. I've accounted for this many times.
What is the evidence that the unconformity is not an erosional surface? In this case the facts I already pointed out: that the strata were clearly stacked horizontally on a straight level surface or they wouldn't be recognizable as strata, which I pointed out is the case, after sagging into the irregularities that NOW exist where formerly a straight level surface existed. Again, if that irregular surface already existed when they were deposited they would not sag into it as coherent formed strata but would have filled in the irregularities the way freshly depositing sediments do.
That's what this thread is supposed to be addressing. We don't argue that tectonic activity can happen after deposition, but that tectonic uplift doesn't turn a conformable boundary into an unconformable boundary. Uh huh. Well, you're wrong and that is precisely what this formation demonstrates, which happens to be precisely what I've been arguing against the conventional view all along.
Instead the whole stack has obviously been deformed, and this must be due to the disturbance of the gneiss beneath it, being pushed up into it, which causes the malleable sediment to sag into its depression while maintaining its original width from its original horizontal deposition, at least on the left.
Yes, Faith, the uplift occurred after the upper strata were deposited (at least most of it). But that observation does NOT lead to the conclusion that there was only one depositional period and one tectonic period that followed deposition. Nor does it lead to the conclusion that the unconformity formed after tectonic motion. Well I just showed you the evidence that it does. That is precisely what this example demonstrates. Too much pride to be honest about it? Edited by Faith, : No reason given.
|
||||||||||||||||||||||||||||||||||||||||||||||||
Faith  Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: |
In response to HBD's diagrams in Message 970:
This is a great find. I'm trying to imagine Faith's rebuttal to this and just can't come up with anything. These are actual observations, not inspections of a photograph; and pretty comprehensive, too. None of these examples look like detachment surfaces. No but most of them do look like the mounded rock beneath the strata above ("Archaean" basement beneath Tapeats) pushed up into that already-existing strata, which is evidenced by the deformation of the formerly horizontal strata over the basement rock, sagging into its depressions etc., which, as also in the other example, would not have been the case if the strata had been deposited after the lower rock was already there. Unfortunately that kind of diagram with its whiteness and thin lines is very hard on my eyes so I can't spend protracted time on them, but I think I got the basic idea and I'll come back to it again later. Edited by Faith, : No reason given.
|
||||||||||||||||||||||||||||||||||||||||||||||||
Faith  Suspended Member (Idle past 1466 days) Posts: 35298 From: Nevada, USA Joined: |
Nevertheless, as you point out, the layers are 'draped', but what you miss is that they also thin toward the higher point of the gneiss.
I think this is another point that is not well understood because the Principal of Horizontality suggests that all sediment is laid down perfectly horizontally. Sediment is not laid down perfectly horizontal, but can be draped over an obstacle or [whatever you would call the opposite effect] in a basin. What, now you are going to defy the law of gravity and the most basic law of Geology with your argument that layers can DEPOSIT nonhorizontally? No way Jose. What you are calling "draping" is clearly the sagging of originally horizontally deposited sediments while still in a soft enough condition to deform without breaking. This can only happen after they were all laid down horizontally in a stack, then they also deform as a stack. Sediments do not "drape," they deposit horizontally. The thinning at the upper parts of such a deformed stack is from stretching. Edited by Faith, : No reason given.
|
||||||||||||||||||||||||||||||||||||||||||||||||
ThinAirDesigns Member (Idle past 2395 days) Posts: 564 Joined:
|
Faith writes: What, now you are going to defy the law of gravity and the most basic law of Geology with your argument that layers can DEPOSIT nonhorizontally? In the interest of my education (and also in the interest of supporting assertions with evidence), could you please direct me to the resources where this "most basic law of geology" is found prohibiting layers from depositing in any manner other than horizontal. It should be super easy for you to find since it is after all "the most basic law of Geology". Thanks JB
|
||||||||||||||||||||||||||||||||||||||||||||||||
edge Member (Idle past 1728 days) Posts: 4696 From: Colorado, USA Joined:
|
What, now you are going to defy the law of gravity and the most basic law of Geology with your argument that layers can DEPOSIT nonhorizontally?
Although I can think of exceptions to the rule, I am not attempting to do so here. The sediments were deposited very close to horizontal. Then they were compressed by all of the deposition above. This is part of lithification.
No way Jose. What you are calling "draping" is clearly the sagging of originally horizontally deposited sediments while still in a soft enough condition to deform without breaking.
Yes, they were being dewatered and lithified.
This can only happen after they were all laid down horizontally in a stack, then they also deform as a stack. Sediments do not "drape," they deposit horizontally. The thinning at the upper parts of such a deformed stack is from stretching.
I could dispute that in a subsiding basin system, but that's not relevant here. The point is that I'm not saying what you think.
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024