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Author Topic:   Origin of the Flood Layers
herebedragons
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Posts: 1513
From: Michigan
Joined: 11-22-2009


Message 241 of 409 (753194)
03-17-2015 6:47 PM
Reply to: Message 231 by Faith
03-17-2015 1:02 PM


I'll say that picture is about as weird as possible.

Of course it is...

The upper stuff looks like it was originally sort of frothy or something, with that front rolled edge, sort of like sticky candy before it hardens, and that when it rolled over the lower stuff the clasts stuck to it.

Have you ever even seen rocks in situ?

It's the Tapeats and it has been eroded to expose the layer underneath. The layer beneath is Vishnu Schist, which is much more resistant to erosion than the Tapeats. That is what the contact surface (the Great Unconformity) looks like at that locale.

It's not even apparent that the clasts are of the same material as the lower layer.

The clasts are Zoroaster Granite, which is intrusive material within the Vishnu Schist.

The dark material is Vishnu Schist and the pinkish material is Zoroaster Granite.

If something isn't clear, and this isn't, you can't expect me just to accept whatever you say about it.

You could follow the images to their source and confirm what I say. You could do a teeny bit of research to verify if what I presented has any validity. You could go to the canyon yourself and collect samples and analyze them to see if what I said holds up. Or... you could just dismiss it as irrelevant and unmeaningful.

HBD


Whoever 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.


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Faith
Member
Posts: 32700
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 242 of 409 (753268)
03-18-2015 4:35 PM
Reply to: Message 227 by herebedragons
03-17-2015 8:21 AM


Layer "A" is deposited. It is then exposed to the surface and subject to erosion. Erosion of layer "A" results in debris which is composed of material that originated in layer "A". Then layer "B" is deposited on top of layer "A". The debris which was a result of erosion of layer "A" and is composed of layer "A" material is then incorporated into layer "B".

Material that is composed of layer "A" that has been incorporated into layer "B" is the "bullet-proof" evidence of what the sequence of events were.

(image above) The clasts are composed of the same material that the lower layer (layer "A") is made of and they have been incorporated into the upper layer (layer "B"). This is the evidence (there is more as well) that layer "A" was exposed to the surface and subject to erosion and then overlain with layer "B" creating an unconformity between the two layers.

Now, how will you respond to evidence?

Apparently you have no idea how patronizing you are to me. Do you know what the word means? It means you talk down to me as if I were a small child. And I don't even think children should be talked to like that.

In this photo there is no question that layer B follows layer A as you say. It also follows in the same order where the Supergroup is tilted, the only argument I've been making being that the *tilting* itself occurred at the same time as the uplift after all the strata were in place above. (Edge says the truncated faults prove it didn't happen in that order). In my scenario the Tapeats would have been laid down over the uppermost layer of the Supergroup before it tilted, and it would have been laid down over the schist and the granite as well. I don't think I've said anything to challenge that order of things.

However I would as usual challenge the timing you consider to be evidenced in this photo.

Layer "A" is deposited. It is then exposed to the surface and subject to erosion. Erosion of layer "A" results in debris which is composed of material that originated in layer "A".

Just as I've interpreted the quartzite boulder embedded in the Tapeats in earlier discussions, I would suggest that there is nothing in this photograph to suggest a long period of erosion before the deposition of the sandstone. For one thing it doesn't even LOOK LIKE the surface of the Vishnu was eroded, it looks to me like a baked and dried-out wrinkled surface that hasn't been eroded, what one might expect of rock that had been subjected to the heat of magma, which became the granite associated with the schist. I'm sure there is other evidence that isn't apparent on the photograph of course, but just by the look of it there is no evidence of erosion requiring me to agree with you.

The thickly fluid sandstone -- (ABE: VISCOUS: that's the word that's been escaping me. /ABE) -- could have picked up fragments of quartz from the schist as it rolled over it if they were loosely embedded in it. Those clasts are obviously not of the same material as the schist, and edge says they are quartz, which is what they look like.

The photo seems to me to show the sandstone as having a thick forward edge to it that stopped at that point before hardening. I don't see any evidence that the Vishnu in front of it was ever eroded or that the sandstone had been eroded away from it after being deposited on it.

If the photo is not deceiving about this thick forward edge it reminds me of that very strange formation in China I've posted on earlier, the striped rolling sandstone shapes that seem to have been squeezed out of a toothpaste tube or a pastry cone, originally a thick sort of paste. I've wondered why we see that kind of sandstone only in that very strange formation in China, but your picture suggests it's really a typical way sandstone occurs, even in America. Here's the formation in China for reference:

This is the evidence (there is more as well) that layer "A" was exposed to the surface and subject to erosion and then overlain with layer "B" creating an unconformity between the two layers.

Among other things, how does an unconformity result from such a sequence and timing of events? What makes it an unconformity even if this order of things was the case? Again, of course I don't agree that your interpretation of the evidence is as ironclad as you think it is, but I still have this question even if you're right. What makes this an "unconformity?"

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : "viscous" added


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Faith
Member
Posts: 32700
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 243 of 409 (753274)
03-18-2015 6:05 PM
Reply to: Message 227 by herebedragons
03-17-2015 8:21 AM


Looking at this photo again, it looks to me like the sandstone had just plucked the quartz out of the Vishnu before it stopped moving forward over the Vishnu, then slightly receded in the process of hardening so that you can see it holding on to the quartz it had just lifted out of the Vishnu. I've marked the edges of the depressions in the Vishnu which fit the shapes of the quartz stuck in the sandstone. In other words, no erosion had to occur to expose that quartz, that's just the way it was embedded in the Vishnu in the first place:


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Faith
Member
Posts: 32700
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 244 of 409 (753276)
03-18-2015 6:26 PM
Reply to: Message 235 by edge
03-17-2015 1:31 PM


When a rock unit erodes at the surface, the produced sediment is always to some degree stripped away by erosion. That would be by mass-wasting, or streams or sheet runoff or debris flows etc. However, if that process is incomplete, there will very often be a zone immediately above weathered rock that includes fragments of that underlying rock.

I gave my alternative interpretation of the Tapeats-Vishnu photo to HBD. The erosion interpretation is plausible of course but I think my version is more plausible.

For instance, in the example I provided earlier, the granite is weathered to granite rock fragments, and grains of quartz, feldspars, and micas, etc. These may be carried far away or be hardly transported at all; but when lithified, they form a sedimentary rock that we call an arkose (usually a sandy or gravel deposit). In the case shown, the sediment was nor far removed from its source and forms a very nice, picturesque deposit known as the Fountain Formation immediately on top of the granite. While the Fountain Formation was deposited in the range of 300-400my ago, it's source was the much older granite.

I appreciate your marking the photograph to show what you mean. I had missed what you said about the Fountain formation's having been deposited "immediately on top of the granite," so assumed it was another version of the GU that included the Tapeats.

However, I never can see the need of those hundreds of millions of years and can't see it here either.

The source of the Fountain formation's being the granite isn't problematic, though it's not clear to me how it got there, and I don't know why the contact between the two is considered to be an unconformity.

If you look up the subject "Red Rocks" you will find a beautiful setting outside of Denver, now used by humans for music concerts. This will be an interesting unconformity, perhaps in a few million years...

Yes it's a nice setting, checked it out, though of course the remark about millions of years as usual has me unconvinced.

Any questions, feel free to ask. This is actually a very interesting and sometimes non-intuitive subject.

Yes it is interesting.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.


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Faith
Member
Posts: 32700
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 245 of 409 (753279)
03-18-2015 7:53 PM
Reply to: Message 243 by Faith
03-18-2015 6:05 PM


Just to be as clear as possible, here's an updated version of that photo showing more precisely how I think the quartz most likely originally fit into the Vishnu:


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edge
Member
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 3.2


(1)
Message 246 of 409 (753280)
03-18-2015 8:15 PM
Reply to: Message 242 by Faith
03-18-2015 4:35 PM


In my scenario the Tapeats would have been laid down over the uppermost layer of the Supergroup before it tilted, and it would have been laid down over the schist and the granite as well. I don't think I've said anything to challenge that order of things.

Why would the Tapeats be laid down over the Vishnu sequence in your scenario? I thought you had all of the sediments deposited before anything else happened. In that case Supergroup rocks should always be between the Tapeats and the Vishnu.

In fact we see Tapeats overlying all formations of the Supergroup in every cross-section visited, not just the uppermost.

Just as I've interpreted the quartzite boulder embedded in the Tapeats in earlier discussions, I would suggest that there is nothing in this photograph to suggest a long period of erosion before the deposition of the sandstone.

When you look at the source of the gravels at the base of the Tapeats, there is no other explanation for their distribution.

Besides, it doesn't have to be a long period of erosion. A short period of erosion could conceivable remove a large part of the rock record. This is one of the things that people often do not understand about unconformities.

For one thing it doesn't even LOOK LIKE the surface of the Vishnu was eroded, it looks to me like a baked and dried-out wrinkled surface that hasn't been eroded, what one might expect of rock that had been subjected to the heat of magma, which became the granite associated with the schist.

Not really. These rocks have been heavily weathered and picture that I showed you attested to that fact.

I'm sure there is other evidence that isn't apparent on the photograph of course, but just by the look of it there is no evidence of erosion requiring me to agree with you.

The relationship of the basal gravel to the underlying rock is an established fact.

The thickly fluid sandstone -- (ABE: VISCOUS: that's the word that's been escaping me. /ABE) -- could have picked up fragments of quartz from the schist as it rolled over it if they were loosely embedded in it.

Where have you ever seen a 'viscous' sandstone?

However, yes, some fluid (possibly even water???) has deposited sand on the large boulders that are directly weathered out of the Vishnu sequence.

Those clasts are obviously not of the same material as the schist, and edge says they are quartz, which is what they look like.

One of them looks like pure quartz the others appear to be granite pegmatite clasts composed of large quartz and feldspar crystals. This distinction, however, is unimportant as the the origin of the fragments. They clearly came from the older rocks. They are not exotic.

The photo seems to me to show the sandstone as having a thick forward edge to it that stopped at that point before hardening.

I think you are confusing the sandstones with volcanic rocks here.

I don't see any evidence that the Vishnu in front of it was ever eroded or that the sandstone had been eroded away from it after being deposited on it.

What do you mean 'in front of it'?

If the photo is not deceiving about this thick forward edge ...

What 'thick forward edge'? The unconformity is a gently dipping surface.

... it reminds me of that very strange formation in China I've posted on earlier, the striped rolling sandstone shapes that seem to have been squeezed out of a toothpaste tube or a pastry cone, originally a thick sort of paste.

So, you are saying that the Tapeats was extruded on to the surface of the earth?

I've wondered why we see that kind of sandstone only in that very strange formation in China, but your picture suggests it's really a typical way sandstone occurs, even in America. Here's the formation in China for reference:

It looks like normal bedding to me. Please explain.

Among other things, how does an unconformity result from such a sequence and timing of events?

Easy. It's called erosion.

What makes it an unconformity even if this order of things was the case? Again, of course I don't agree that your interpretation of the evidence is as ironclad as you think it is, but I still have this question even if you're right. What makes this an "unconformity?"

I have given you a definition and a link to an explanation of unconformities. Are you not reading our posts?
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edge
Member
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 3.2


(1)
Message 247 of 409 (753281)
03-18-2015 8:18 PM
Reply to: Message 245 by Faith
03-18-2015 7:53 PM


Just to be as clear as possible, here's an updated version of that photo showing more precisely how I think the quartz most likely originally fit into the Vishnu:

But here is how they really look:

Do we really need to explain this to you?

Edited by edge, : No reason given.


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edge
Member
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 3.2


Message 248 of 409 (753283)
03-18-2015 8:25 PM
Reply to: Message 243 by Faith
03-18-2015 6:05 PM


Looking at this photo again, it looks to me like the sandstone had just plucked the quartz out of the Vishnu before it stopped moving forward over the Vishnu, then slightly receded in the process of hardening so that you can see it holding on to the quartz it had just lifted out of the Vishnu.

What do you mean by the sandstone 'stopped moving forward'?

You are making no sense at all.

I've marked the edges of the depressions in the Vishnu which fit the shapes of the quartz stuck in the sandstone. In other words, no erosion had to occur to expose that quartz, that's just the way it was embedded in the Vishnu in the first place:

So, all of these fragmental pegmatites just happened to form in the schist right at the surface where your sandstone lava flow(?) just picked them up and put them back down.

This is just bizarre.

As a footnote, I knew way back in post 210 that this discussion was going to go to the dogs....

Edited by edge, : No reason given.

Edited by edge, : No reason given.


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edge
Member
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 3.2


Message 249 of 409 (753284)
03-18-2015 8:42 PM
Reply to: Message 244 by Faith
03-18-2015 6:26 PM


However, I never can see the need of those hundreds of millions of years and can't see it here either.

A photograph is not going to give you that information. It is the additional information that we have regarding these rocks that tell us of the age difference.

But that's not the point of this discussion. The point is that erosion is happening in the geological record before the end of sedimentary deposition in the Grand Canyon area.

The source of the Fountain formation's being the granite isn't problematic, though it's not clear to me how it got there, ...

That is because it was eroded in place and you refuse to accept that interpretation.

and I don't know why the contact between the two is considered to be an unconformity.

As I said earlier, you have been told this. Your refusal to accept an erosional event early in the geological history of the GC area has led you to a state of confusion.
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edge
Member
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 3.2


Message 250 of 409 (753289)
03-18-2015 10:19 PM


This schematic depicts how weathering occurs.


The main difference between this and the unconformities that we are looking at is that most of the weathered material is transported away to some degree. In the Toroweap/Vishnu picture we see only a few fragments of the quartz and pegmatite remaining on the bedrock surface before the they are inundated with sand. In the case of the Fountain Formation, there is a deep deposit of granitic 'grus' (basically a granitic sand/pebble deposit) immediately on top of the bedrock surface.

In any case they represent the same thing - a period of erosion prior to continued sedimentation.

I chose this image because it shows what would happen to a quartz vein during weathering and eventual transport. If removal were near complete, we would expect to just see a few clasts resting on the bedrock surface.

And guess what we actually see in HBD's picture of the Great Unconformity.


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herebedragons
Member
Posts: 1513
From: Michigan
Joined: 11-22-2009


(2)
Message 251 of 409 (753290)
03-18-2015 10:34 PM
Reply to: Message 243 by Faith
03-18-2015 6:05 PM


First of all, I am sorry you feel I patronize you. I am sincerely trying to be kind and patient and try to explain things simply and in way that I think should be easy to understand. I don't have a feeling that I am superior to you, but I do understand some things that you don't and I try to get them across to you.

So a couple points about your interpretation...

>That picture was only meant to illustrate clasts from the older layer that had been incorporated into the younger, overlaying layer. It is NOT the big picture of the unconformity...a picture like that wouldn't fit on the screen.

>The reason that it is more plausible that the surfaces you see in that picture were exposed by erosion is that they are at the bottom of the Grand Canyon. Everything at the bottom of the canyon was exposed by erosion. Why would you think it is more plausible that it is shaped like that because it was once viscous?

>Remember, in your scenario, this was covered by the whole stack of Paleozoic sediments that were squeezing the water out of these lower layers. How could they shrink like that while being compressed?

>Don't you think those depressions that you outlined in yellow look more like running water carved them out rather than the clasts fit in them? There is a good strong source of running water at the bottom of the canyon.

>If the clasts were part of the Vishnu Schist before this viscous sandstone "plucked them out," how did they get incorporated into the Vishnu in the first place? You already pointed out that they don't look like the surrounding rock.

I was going to try to post a summary of what I have presented so far regarding the Great Unconformity but I just don't have the time right now. Maybe this weekend. In the mean-time maybe you could review my Message 103 from the Evidence that the Great Unconformity did not Form Before the Strata above it. It covers the details regarding the contact between the Tapeats and the basement rocks.

HBD


Whoever 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.


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Faith
Member
Posts: 32700
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 252 of 409 (753294)
03-18-2015 11:46 PM
Reply to: Message 246 by edge
03-18-2015 8:15 PM


In my scenario the Tapeats would have been laid down over the uppermost layer of the Supergroup before it tilted, and it would have been laid down over the schist and the granite as well. I don't think I've said anything to challenge that order of things.

Why would the Tapeats be laid down over the Vishnu sequence in your scenario? I thought you had all of the sediments deposited before anything else happened. In that case Supergroup rocks should always be between the Tapeats and the Vishnu.

Unless some of them became that very schist when the uplift occurred (yes I'm still considering it very possible because of all the different kinds of rock that have been found in it and because of the granite within it which I know you think of on a different time scale but could have been released as magma within the same time frame as the uplift and all the rest of it), pushing the schist up alongside the remaining Supergroup, now broken and tilted. (And since you want an explanation for how the faulting could have managed not to extend up into the Tapeats if it all happened in this order, I figure that's because the faulting occurred while the Supergroup blocks were being shifted laterally under the Tapeats in the same movement that broke them and tilted them. If they'd stayed in one place the faults would have continued upward, but if they slid sideways that would have been prevented.

In fact we see Tapeats overlying all formations of the Supergroup in every cross-section visited, not just the uppermost.

OK, but because the Supergroup always has Tapeats overlying it, doesn't mean that Tapeats can't also overlie schist somewhere else.

Just as I've interpreted the quartzite boulder embedded in the Tapeats in earlier discussions, I would suggest that there is nothing in this photograph to suggest a long period of erosion before the deposition of the sandstone.

When you look at the source of the gravels at the base of the Tapeats, there is no other explanation for their distribution.

I don't think these gravels you keep mentioning have actually been shown in a photo here, have they? Sorry I missed it, if so. And what do you mean by "their distribution" and what is it about these gravels that requires this explanation? Again I'm sorry if I missed your explanation. I have a lot to absorb here, very likely I've missed stuff while I'm thinking about something else.

Besides, it doesn't have to be a long period of erosion. A short period of erosion could conceivable remove a large part of the rock record. This is one of the things that people often do not understand about unconformities.

OK but how short?

For one thing it doesn't even LOOK LIKE the surface of the Vishnu was eroded, it looks to me like a baked and dried-out wrinkled surface that hasn't been eroded, what one might expect of rock that had been subjected to the heat of magma, which became the granite associated with the schist.

Not really. These rocks have been heavily weathered and picture that I showed you attested to that fact.

Do you mean the one I've been discussing, where the Tapeats is shown partly covering it, with the quartz clasts stuck in it?

I'm sure there is other evidence that isn't apparent on the photograph of course, but just by the look of it there is no evidence of erosion requiring me to agree with you.

The relationship of the basal gravel to the underlying rock is an established fact.

What basal gravel? It isn't showing in this photograph, right? The only thing we see is the hunks of quartz (or pegmatite) which look like they were just plucked out of the Vishnu.

The thickly fluid sandstone -- (ABE: VISCOUS: that's the word that's been escaping me. /ABE) -- could have picked up fragments of quartz from the schist as it rolled over it if they were loosely embedded in it.

Where have you ever seen a 'viscous' sandstone?
.

Never, of course, but this sandstone looks like it had to have once been describable that way, before hardening, just as those strange formations in China suggest the same previous condition. Or do you have another explanation for those Chinese sandstone shapes?

However, yes, some fluid (possibly even water???) has deposited sand on the large boulders that are directly weathered out of the Vishnu sequence.

"Deposited sand on?" Are we looking at the same picture? I see an expanse of what you identified as Tapeats sandstone with these quartz or pegmatite boulders stuck in its front edge ("front" meaning where the Vishnu schist begins to be exposed in the foreground, and where it looks (to me) like there are holes in the Vishnu that very nicely fit the size and shape of the boulders.) I don't any sand "deposited" on the boulders, I see boulders stuck in the sandstone. (By "boulders" I'm assuming you mean the quartz clasts. There is no way to tell the scale in that picture but if they are "boulders" perhaps they are as large as that quartzite boulder I've mentioned before, which is about fifteen feet in height. Do you know the scale of the objects in the photo?)

Those clasts are obviously not of the same material as the schist, and edge says they are quartz, which is what they look like.

One of them looks like pure quartz the others appear to be granite pegmatite clasts composed of large quartz and feldspar crystals. This distinction, however, is unimportant as the the origin of the fragments. They clearly came from the older rocks. They are not exotic.

I assume you are reiterating that they came out of the Vishnu schist?

The photo seems to me to show the sandstone as having a thick forward edge to it that stopped at that point before hardening.

I think you are confusing the sandstones with volcanic rocks here.

Are you still looking at the same picture I am? I'm talking about the one HBD discussed, where the Tapeats is shown with the quartz (or pegmatite) clasts (boulders?) stuck in it. Nobody has identified any volcanic rocks in this picture and I don't see any, just the Tapeats sandstone overlying the schist, which is exposed in the foreground of the picture.

I don't see any evidence that the Vishnu in front of it was ever eroded or that the sandstone had been eroded away from it after being deposited on it.

What do you mean 'in front of it'?

In the foreground of the picture.

If the photo is not deceiving about this thick forward edge ...

What 'thick forward edge'? The unconformity is a gently dipping surface.

OK, here's how I see it:

I've outlined the top and bottom of what I see as the "thick forward edge" of the sandstone, which I think is pretty clearly defined by the shadow that shows it's vertical or near-vertical, although the surface of the sandstone in the background is horizontal. This "forward edge" is where the clasts / boulders are stuck. The size of the boulders should indicate how high this forward edge is, but I don't see any way in the photo itself to determine the scale.

If this is not your view please draw a picture showing how you see it.

... it reminds me of that very strange formation in China I've posted on earlier, the striped rolling sandstone shapes that seem to have been squeezed out of a toothpaste tube or a pastry cone, originally a thick sort of paste.

So, you are saying that the Tapeats was extruded on to the surface of the earth?

Yes that's what it looks like to me in this picture of this location. Not easy to reconcile with the Flood scenario I guess, but that's what it looks like. A thick viscous sandstone moving forward (toward the foreground) over the schist, then stopping its forward movement right over some clasts embedded in the schist, that then stick in it and get pulled up out of their position in the schist when the sandstone hardens and retracts.

I've wondered why we see that kind of sandstone only in that very strange formation in China, but your picture suggests it's really a typical way sandstone occurs, even in America. Here's the formation in China for reference:

It looks like normal bedding to me. Please explain.

Are you talking about the Chinese formation or the photo now? The Chinese formation does sort of look like "bedding," puffy folds of striped cloth bedding. I can't imagine how it looks "normal" to you. Where else on earth is anything like this formation seen?

Among other things, how does an unconformity result from such a sequence and timing of events?

Easy. It's called erosion.

Well, in the case of this picture the erosion looks like it may have been created by the Tapeats sandstone flowing over it and dislodging whatever can be dislodged.

What makes it an unconformity even if this order of things was the case? Again, of course I don't agree that your interpretation of the evidence is as ironclad as you think it is, but I still have this question even if you're right. What makes this an "unconformity?"

I have given you a definition and a link to an explanation of unconformities. Are you not reading our posts?

Right, the erosion at the surface before being covered by the sandstone. Which again I don't find convincing.

Edited by Faith, : No reason given.


This message is a reply to:
 Message 246 by edge, posted 03-18-2015 8:15 PM edge has responded

Replies to this message:
 Message 254 by edge, posted 03-19-2015 12:28 AM Faith has responded

    
Faith
Member
Posts: 32700
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.1


Message 253 of 409 (753295)
03-19-2015 12:09 AM
Reply to: Message 247 by edge
03-18-2015 8:18 PM


But here is how they really look:

Do we really need to explain this to you?

Don't think so: veins of the quartz (or pegmatite) embedded in the Vishnu schist.

However, I'd guess that wall of rock was probably not subjected to a mass of viscous sandstone rolling over it as is shown in the other picture. Otherwise the sandstone would very likely have picked up chunks of the stuff here too.

Edited by Faith, : No reason given.


This message is a reply to:
 Message 247 by edge, posted 03-18-2015 8:18 PM edge has responded

Replies to this message:
 Message 255 by edge, posted 03-19-2015 12:30 AM Faith has not yet responded

    
edge
Member
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 3.2


(1)
Message 254 of 409 (753296)
03-19-2015 12:28 AM
Reply to: Message 252 by Faith
03-18-2015 11:46 PM


OK, but because the Supergroup always has Tapeats overlying it, doesn't mean that Tapeats can't also overlie schist somewhere else.

That's not the point.

The point is that you said 'the upppermost'.

You were wrong. Again.

OK but how short?

Not material. I'm just showing that you don't really know much about unconformities.

Yes, the clasts that HBD showed you and the beds that I showed you are gravels.

So, yes, you missed something. Again.

Do you mean the one I've been discussing, where the Tapeats is shown partly covering it, with the quartz clasts stuck in it?

Yes, and practically every other one you've seen.

Some of them have paleosoils.

What basal gravel? It isn't showing in this photograph, right? The only thing we see is the hunks of quartz (or pegmatite) which look like they were just plucked out of the Vishnu.

So, you are saying that they are transported by moving water? Do you understand that is erosion?

Never, of course, but this sandstone looks like it had to have once been describable that way, before hardening, just as those strange formations in China suggest the same previous condition. Or do you have another explanation for those Chinese sandstone shapes?

As many times as you have been demonstrabl wrong, you expect anyone to believe this? Yes, they are sedimentary rocks of different colors. Probably also photographed through a filter.

"Deposited sand on?" Are we looking at the same picture? I see an expanse of what you identified as Tapeats sandstone with these quartz or pegmatite boulders stuck in its front edge ("front" meaning where the Vishnu schist begins to be exposed in the foreground, and where it looks (to me) like there are holes in the Vishnu that very nicely fit the size and shape of the boulders.) I don't any sand "deposited" on the boulders, I see boulders stuck in the sandstone. (By "boulders" I'm assuming you mean the quartz clasts. There is no way to tell the scale in that picture but if they are "boulders" perhaps they are as large as that quartzite boulder I've mentioned before, which is about fifteen feet in height. Do you know the scale of the objects in the photo?)

Whatever the scale, the large clasts would not be transported along with the finer sands.

And no, Faith, there is no 'front' in this photo. It is like a cross section.

So, you are wrong again...

Are you still looking at the same picture I am? I'm talking about the one HBD discussed, where the Tapeats is shown with the quartz (or pegmatite) clasts (boulders?) stuck in it. Nobody has identified any volcanic rocks in this picture and I don't see any, just the Tapeats sandstone overlying the schist, which is exposed in the foreground of the picture.

You are the one referring to the sandstone as a 'viscous flow'. I have no idea what you are talking about and I'm pretty sure you don't either.

In the foreground of the picture.

That would be 'below', not 'in front of'.

I've outlined the top and bottom of what I see as the "thick forward edge" of the sandstone, which I think is pretty clearly defined by the shadow that shows it's vertical or near-vertical, although the surface of the sandstone in the background is horizontal. This "forward edge" is where the clasts / boulders are stuck. The size of the boulders should indicate how high this forward edge is, but I don't see any way in the photo itself to determine the scale.

There is no 'forward edge'. This photo is like a cross-section.

Yes that's what it looks like to me in this picture of this location.

Well, I'm sure you would know.

It's sort of like that viscous sand flow in Never Never Land.

Not easy to reconcile with the Flood scenario I guess, but that's what it looks like.

Well, if it looks so, then it must be.

A thick viscous sandstone moving forward (toward the foreground) over the schist, then stopping its forward movement right over some clasts embedded in the schist, that then stick in it and get pulled up out of their position in the schist when the sandstone hardens and retracts.

Sure, it happens everywhere.

Are you talking about the Chinese formation or the photo now? The Chinese formation does sort of look like "bedding," puffy folds of striped cloth bedding. I can't imagine how it looks "normal" to you. Where else on earth is anything like this formation seen?

Parallel beds of different colors? What's the problem?

It's kind of funny how this article on the Danxia rocks don't mention sedimentary flows or toothpaste-like structures....
http://en.wikipedia.org/wiki/Danxia_landform

Well, in the case of this picture the erosion looks like it may have been created by the Tapeats sandstone flowing over it and dislodging whatever can be dislodged.

Evidence that this happened? Perhaps an example of a sand flow?

Right, the erosion at the surface before being covered by the sandstone. Which again I don't find convincing.

Although you can't really say why and have no alternative explanation that exists in this reality.

ETA: By the way, how do sand flows retain their cross-bedding structures?

Edited by edge, : No reason given.


This message is a reply to:
 Message 252 by Faith, posted 03-18-2015 11:46 PM Faith has responded

Replies to this message:
 Message 256 by Faith, posted 03-19-2015 12:34 AM edge has responded

  
edge
Member
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 3.2


Message 255 of 409 (753297)
03-19-2015 12:30 AM
Reply to: Message 253 by Faith
03-19-2015 12:09 AM


However, I'd guess that wall of rock was probably not subjected to a mass of viscous sandstone rolling over it as is shown in the other picture. Otherwise the sandstone would very likely have picked up chunks of the stuff here too.

So, you admit that there was erosion going on at the Great Unconformity.
This message is a reply to:
 Message 253 by Faith, posted 03-19-2015 12:09 AM Faith has not yet responded

  
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