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Author Topic:   Young earth explanations for Angular Unconformities
edge
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Posts: 3904
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 4.3


(2)
Message 166 of 202 (796741)
01-03-2017 7:59 PM
Reply to: Message 160 by Faith
01-03-2017 7:37 PM


I haven't "seen" any of your claims so far.

Of course not. I never expected you to.

It's all a big cheat.

Well, if you don't know the rules of the game, everything seems like a cheat.

As always, there comes a point when discussions with you devolve into you making unverifiable claims in order to win the argument. This gets old.

I'm sorry, but this is partly a technical discussion. I am trying to make it simpler, but have apparently failed.

The story of unconformities is a huge and complex subject. But important and fascinating as well.


This message is a reply to:
 Message 160 by Faith, posted 01-03-2017 7:37 PM Faith has responded

Replies to this message:
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Faith
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Posts: 25610
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.0


Message 167 of 202 (796742)
01-03-2017 8:01 PM
Reply to: Message 164 by edge
01-03-2017 7:55 PM


It had to go somewhere on either theory, and as I said before if it was all eroded away at the surface there would be some evidence of it in the folds of the rocks, but apparently there isn't. On my scenario I suggest it was pushed out at the "front" of the formation, the front being the part exposed to view in all the pictures. There's usually lots of rubble around formations. Or it got pushed along the horizontal path of the unconformity. Somewhere there is an unidentified pile of rubble that is where it went.
This message is a reply to:
 Message 164 by edge, posted 01-03-2017 7:55 PM edge has responded

Replies to this message:
 Message 171 by edge, posted 01-03-2017 8:20 PM Faith has not yet responded
 Message 172 by Percy, posted 01-03-2017 8:33 PM Faith has not yet responded

    
Faith
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Posts: 25610
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.0


Message 168 of 202 (796743)
01-03-2017 8:04 PM
Reply to: Message 166 by edge
01-03-2017 7:59 PM


Oh in that case far be it from me to interfere. I'll go find something else to do. Carry on.
This message is a reply to:
 Message 166 by edge, posted 01-03-2017 7:59 PM edge has not yet responded

    
Percy
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Posts: 15647
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.5


(1)
Message 169 of 202 (796744)
01-03-2017 8:06 PM
Reply to: Message 164 by edge
01-03-2017 7:55 PM


edge writes:

What I'm saying is that the portions of the fold that were above the current location of the unconformity (the red lines) are gone.

Oh, I see what you're saying. I thought that by "lower sequence" you meant only what exists today, but I see what you mean now.

--Percy


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edge
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Posts: 3904
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 4.3


Message 170 of 202 (796746)
01-03-2017 8:14 PM
Reply to: Message 165 by Percy
01-03-2017 7:59 PM


No, Faith, I never said anything like that, and until just now you never said that was your understanding of what I said. You might at least try keeping to a consistent story.

I understood you completely and it made perfect sense. There may well be a large sequence of rocks stratigraphically above the ones we see at Siccar, but still older than the Red Sand. They would have been folded along with the lower sequence but are not eroded completely away.

The thing is that we do not have the information here. It probably exists, but I'm not sure that it's worth the time to track down.

Summarizing the big problems with your fantasy scenario, cubic miles of strata cannot disappear without a trace (meaning no remains of rubble or signs of shearing), disturbances to buried strata cannot fail to disturb overlying strata, rocks weather to form the appearance of age according to their composition and length of exposure and not how long ago they formed, and sedimentary rocks do not form by drying.

Funny how a simple question can have so many implications ...
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 Message 165 by Percy, posted 01-03-2017 7:59 PM Percy has acknowledged this reply

  
edge
Member
Posts: 3904
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 4.3


Message 171 of 202 (796747)
01-03-2017 8:20 PM
Reply to: Message 167 by Faith
01-03-2017 8:01 PM


It had to go somewhere on either theory, and as I said before if it was all eroded away at the surface there would be some evidence of it in the folds of the rocks, but apparently there isn't.

Well, that fact that there are eroded cobbles of the lower rocks at the base of the Red Sand suggests that it was simply removed by mechanical erosion.

On my scenario I suggest it was pushed out at the "front" of the formation, ...

Then one should be able to find it.

... the front being the part exposed to view in all the pictures.

There you just lost me. There is nothing showing there.

There's usually lots of rubble around formations. Or it got pushed along the horizontal path of the unconformity. Somewhere there is an unidentified pile of rubble that is where it went.

Well, some of it is found as beds in higher layers in the Red Sand. That suggests erosion as the culprit.

Edited by edge, : No reason given.


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 Message 167 by Faith, posted 01-03-2017 8:01 PM Faith has not yet responded

  
Percy
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Posts: 15647
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.5


Message 172 of 202 (796749)
01-03-2017 8:33 PM
Reply to: Message 167 by Faith
01-03-2017 8:01 PM


Faith writes:

It had to go somewhere on either theory, and as I said before if it was all eroded away at the surface there would be some evidence of it in the folds of the rocks, but apparently there isn't.

The scenario you describe can and does happen. As soon as some strata has been uplifted above the nearby landscape, sediments from the uplifted region will be deposited upon the lower elevations. If the region remains uplifted long enough then even the lower elevations will erode away, potentially leaving no signs of the eroded material in the area. But if the region subsides again before that can happen then the sedimentary deposits may well be preserved, possibly to be exposed again in the future for us to find. Perhaps Edge knows of some examples.

On my scenario I suggest it was pushed out at the "front" of the formation, the front being the part exposed to view in all the pictures.

In your scenario the material pushed to the "front" of the formation while buried is unlikely to be the same part that erosion just happens to reveal.

There's usually lots of rubble around formations.

That's scree and has nothing to do with the deformation of strata. It forms after exposure due to erosive and weathering forces.

Somewhere there is an unidentified pile of rubble that is where it went.

This contradicts what you said just before about the rubble being at the "front...in all the pictures," but regardless this is just the kind of evidence you need to find, cubic miles of broken off rubble from the strata of the angular unconformity. I liked the label Edge had for it, the "room" problem. Basically it means that everything has to be somewhere - it can't just disappear.

--Percy


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 Message 167 by Faith, posted 01-03-2017 8:01 PM Faith has not yet responded

    
herebedragons
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Posts: 1334
From: Michigan
Joined: 11-22-2009
Member Rating: 6.4


(1)
Message 173 of 202 (796755)
01-03-2017 11:23 PM
Reply to: Message 166 by edge
01-03-2017 7:59 PM


Well, if you don't know the rules of the game, everything seems like a cheat.

AIG posted a link to a rationalwiki article Not even wrong. Here:Message 92 It describes these discussions about geology with Faith rather well.

It's like we are discussing an alternate universe... dozens and dozens of posts on things like how it is impossible for sediment to deposit on a slope, how a stream can't cut down through an uplift, how an unconformity is actually a slip fault, how erosion cannot produce a flat plain, how water can flow underground and produce buried canyons... etc, etc... all the time being told that we are nuts and completely out of touch with reality. Not even wrong... we are talking about an alternate reality that Faith sees and we don't.

HBD

Edited by herebedragons, : Forgot a link to AIGS post


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.


This message is a reply to:
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Replies to this message:
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Tanypteryx
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Posts: 1518
From: Oregon, USA
Joined: 08-27-2006
Member Rating: 5.0


(2)
Message 174 of 202 (796757)
01-04-2017 12:07 AM
Reply to: Message 173 by herebedragons
01-03-2017 11:23 PM


all the time being told that we are nuts and completely out of touch with reality.

Not even wrong... we are talking about an alternate reality that Faith sees and we don't.

You have described this perfectly.

It reminds me of a sci-fi movie where the time traveler ends up in a mental ward because no one can understand what she is talking about. A complete break with reality.

Faith msg 105 writes:

the tectonic pressure should have had the effect of hardening the rock at the same time it folded it.

Are there some references in physics, chemistry, and geology that would explain your reasoning here?

I'm sure there are though I rely on my intuitive genius about such things, and this is really quite recognizable by anyone I would think. Oh maybe not you, but you know, most anyone. Such intense pressure on damp porous shapable stuff would force out the water enough to harden it some. Kinda obvious dontcha think?


What if Eleanor Roosevelt had wings? -- Monty Python

One important characteristic of a theory is that is has survived repeated attempts to falsify it. Contrary to your understanding, all available evidence confirms it. --Subbie

If evolution is shown to be false, it will be at the hands of things that are true, not made up. --percy


This message is a reply to:
 Message 173 by herebedragons, posted 01-03-2017 11:23 PM herebedragons has not yet responded

Replies to this message:
 Message 177 by edge, posted 01-04-2017 2:49 PM Tanypteryx has acknowledged this reply

    
Faith
Member
Posts: 25610
From: Nevada, USA
Joined: 10-06-2001
Member Rating: 1.0


Message 175 of 202 (796779)
01-04-2017 1:51 PM


a review
This thread has lurched from topic to topic without any closure on any of them. Here are a few topics I remember off the top of my head.

I mentioned the apparently equal weathering above and below the unconformity at Siccar Point as evidence that the standard interpretation is false: i.e., that the lower section was laid down and then tilted, and then eroded, and that a long time later the upper section was deposited on top of it. Since millions of years are usually ascribed to such processes, particularly the erosion phase, there should be a difference in weathering apparent between the upper and lower blocks of strata, but they show no such difference.

Edge responded that the upper was deposited quite close to the tilting of the lower, based on some claim of the formations having been built near a shoreline. This topic didnt get pursued. My response is just that such shorelines are imaginary. I dont recall seeing an answer to that from edge.

To my argument that the lower section was tectonically tilted/folded, edge said there is no evidence of tectonic structures. When I asked him to explain how the tilting occurred without tectonic pressure he eventually said of course there was tectonic pressure, he wasnt denying that. So why then make an issue of there being no tectonic structures? I think he answered this somewhere but I dont recall the answer and I find it hard to follow this sort of verbal game-playing anyway.

When I elaborated that the lower section wasnt just tilted but folded, and put up the drawing by Lyell demonstrating that, he said there is none of the usual evidence of folding and posted a picture which I guess shows stretched rock. But we KNOW that the rock was folded so what does this supposed absence of evidence demonstrate? Just more game-playing obfuscation it seems to me.

There are also none of the usual signs of shearing, he says, to counter my idea that the unconformity must have been formed by shearing between the upper and lower sections. I dont really care if literal shearing is how it happened, the point is that the two sections moved against each other. The result could be lumpy. He answered that there should be evidence in any case. I dont find this very convincing. A lack of evidence isnt normally considered to be acceptable evidence of the absence of a phenomenon.

At some point edge put up a picture of an unconformity with a granite base and sandstone layers topping it. He kept referring to the granite as forming boulders. I missed his point Im afraid, I still dont know what he intended to be arguing with that picture. But it was interesting for the fact that a depression in the granite was not filled by sand from the sandstone layers above, which to my mind shows that the depression occurred after the sandstone was in place.

Then he posted a picture of folded rock above some flat layers that was intended to answer my idea that the folding of the rock at Siccar Point was made possible by a great weight of strata that would have been above the folded rock. He claimed there had been no strata above the folded rock in the picture, but how does he know that? If the rock is very old then it is very likely that just like Siccar Point there would have been a deep stack above it at the time of folding.

Through all these different issues there was Percys constant refrain about how my argument fails because there would have been an enormous amount of material that just disappeared. Well, it disappeared from the pictures we have of such formations, but that doesnt mean it didnt get pushed somewhere that just isnt recognized, outside the formation as we normally view it, even perhaps the cause of the formations being exposed on a certain surface; or deep within it somewhere we also dont get to see.

ABE: Consider that the Grand Canyon must have been emptied of an enormous amount of material but where is the evidence of that? I think it's probably in rubble formations along the path of the Colorado River and into the Gulf of California, but there isn't anything obvious about this.

This thread has bounced from one issue to another without any of them being addressed to any useful extent, in some cases not addressed at all.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.

Edited by Faith, : No reason given.


Replies to this message:
 Message 176 by edge, posted 01-04-2017 2:34 PM Faith has responded

    
edge
Member
Posts: 3904
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 4.3


(1)
Message 176 of 202 (796781)
01-04-2017 2:34 PM
Reply to: Message 175 by Faith
01-04-2017 1:51 PM


Re: a review
I mentioned the apparently equal weathering above and below the unconformity as evidence that the standard interpretation is false: i.e., that the lower section was laid down and then tilted, and that a long time later the upper section was deposited on top of it. Since millions of years are usually ascribed to such blocks of strata, there should be a difference in weathering apparent between the two blocks, but they show no such difference.

No. I said that the weathered rock was removed by mechanical erosion and that the lower rocks were covered shortly after erosion.

To my argument that the lower section was tectonically tilted/folded, edge said there is no evidence of tectonic structures. When I asked him to explain how the tilting occurred without tectonic pressure he eventually said of course there was tectonic pressure, he wasnt denying that. So why then make an issue of there being no tectonic structures? I think he answered this somewhere but I dont recall the answer and I find it hard to follow this sort of verbal game-playing anyway.

That is because I was referring to a fault plane not folding.

In fact, in the images of the unconformity there is no tectonic structure. There are just tilted beds. Until you look at a larger area do you see actual folds.

When I elaborated that the lower section wasnt just tilted but folded, and put up the drawing by Lyell demonstrating that, he said there is none of the usual evidence of folding and posted a picture which I guess shows stretched rock. But we KNOW that the rock was folded so what does this supposed absence of evidence demonstrate? Just more game-playing obfuscation it seems to me.

Again, I was referring to the images only.

In fact, if you had no other information, you could not tell that there was a fold or anything about that fold. There are other ways to tilt bedding planes.

There are also none of the usual signs of shearing, he says, to counter my idea that the unconformity must have been formed by shearing between the upper and lower sections. I dont really care if literal shearing is how it happened, the point is that the two sections moved against each other. The result could be lumpy. He answered that there should be evidence in any case. I dont find this very convincing. A lack of evidence isnt normally considered to be acceptable evidence of the absence of a phenomenon.

I have seen probably thousands of fault surfaces. Unless they have been somehow modified by deformation and heat, they always show signs of motion. The only way to get relative motion without any shear is to move the two sides directly apart. And I've seen that too.

And the amount of movement involved, AFAICT about Faith's scenario, is ample. It should absolutely show signs of shear.

At some point edge put up a picture of an unconformity with a granite base and sandstone layers topping it. He kept referring to the granite as forming boulders. I missed his point Im afraid, I still dont know what he intended to be arguing with that picture. But it was interesting for the fact that a depression in the granite was not filled by sand from the sandstone layers above, which to my mind shows that the depression occurred after the sandstone was in place.

An artifact of an oblique image.

There were pretty obvious fractures in the granite showing spheroidal weathering that would only occur during long periods of weathering. The purpose of this image was to show Faith a location where the underlying rocks actually were more weathered than the rocks overlying an unconformity. This is due to the fact that the granite was not being mechanically removed as it was weathered. I can see that my attempt to help the understanding of unconformities failed.

Then he posted a picture of folded rock above some flat layers that was intended to answer my idea that the folding of the rock at Siccar Point was made possible by a great weight of strata that would have been above the folded rock. He claimed there had been no strata above the folded rock in the picture, but how does he know that? If the rock is very old then it is very likely that just like Siccar Point there would have been a deep stack above it at the time of folding.

Actually, I never said such a thing. The point was that in real detachment situations, the upper rocks are more likely to fold than the lower. It was also to show how a sharp, smooth shear surface forms between the two blocks in a shear zone.

Through all these different issues there was Percys constant refrain about how my argument fails because there would have been an enormous amount of material that just disappeared. Well, it disappeared from the pictures we have of such formations, but that doesnt mean it didnt get pushed somewhere that just isnt recognized, outside the formation as we normally view it, even perhaps the cause of the formations being exposed on a certain surface; or deep within it somewhere we also dont get to see.

And then you are challenged to find this deposit.

But you also left out the point that folding of the underlying rocks would create room problems for the overlying material that would be deformed during folding. You can't just fold rocks without creating zones of dilation and compression that would affect the overlying units.

This thread has bounced from one issue to another without any of them being addressed to any useful extent, in some cases not addressed at all.

Perhaps you could read our posts more carefully and leave your presuppositions behind for just a moment. I think that most people here have good understanding of the points being made.
This message is a reply to:
 Message 175 by Faith, posted 01-04-2017 1:51 PM Faith has responded

Replies to this message:
 Message 179 by Percy, posted 01-04-2017 3:58 PM edge has responded
 Message 183 by Faith, posted 01-04-2017 9:48 PM edge has responded

  
edge
Member
Posts: 3904
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 4.3


(1)
Message 177 of 202 (796788)
01-04-2017 2:49 PM
Reply to: Message 174 by Tanypteryx
01-04-2017 12:07 AM


You have described this perfectly.

It reminds me of a sci-fi movie where the time traveler ends up in a mental ward because no one can understand what she is talking about. A complete break with reality.


Exactly. I feel kind of like Alice in Wonderland when I read Faith's posts. I have no idea where to even start discussing her points. So often, I simply have to guess what is going on.

I liken her scenario about folding the lower rocks but leaving the upper rocks intact, to a horizontal trash compactor. The difference is that compactors use high-strength steel to confine the compressed material, not sandstone.

And the container still shows signs of shearing ...


This message is a reply to:
 Message 174 by Tanypteryx, posted 01-04-2017 12:07 AM Tanypteryx has acknowledged this reply

Replies to this message:
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Percy
Member
Posts: 15647
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.5


Message 178 of 202 (796793)
01-04-2017 3:20 PM
Reply to: Message 177 by edge
01-04-2017 2:49 PM


edge writes:

I liken her scenario about folding the lower rocks but leaving the upper rocks intact, to a horizontal trash compactor. The difference is that compactors use high-strength steel to confine the compressed material, not sandstone.

Adding some more explanation in case Faith reads this exchange between you and Tanypteryx, another difference between trash compactors and tectonic forces is that rock isn't significantly compressible the way trash is. Granite density varies by less than 5%, sandstone by 25%, shale by 15%, slate by less than 5%. Tectonic forces on rock move, fold and bend rock rather than compressing it very much.

It's also worth noting that tectonic forces pushing up from below cannot exert significantly greater pressure on strata than already exists because that would require an additional force pushing down. But the only force pushing down is gravity and no additional downward force can be brought to bear on the layers of strata, not unless more sedimentary layers are deposited on the top strata. It's like lifting a cheerleader up into the air - the cheerleader won't be compressed by the force (only slightly greater than her weight) pushing her into the air unless a new force starts pushing her down from above.

And the container still shows signs of shearing ...

Clarifying what I think you mean with your scenario of a horizontal trash compactor, very visible shearing should be apparent between the upper uncompressed portion and the bottom compressed portion.

--Percy


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 Message 177 by edge, posted 01-04-2017 2:49 PM edge has not yet responded

    
Percy
Member
Posts: 15647
From: New Hampshire
Joined: 12-23-2000
Member Rating: 2.5


Message 179 of 202 (796796)
01-04-2017 3:58 PM
Reply to: Message 176 by edge
01-04-2017 2:34 PM


Re: a review
edge writes:

I mentioned the apparently equal weathering above and below the unconformity as evidence that the standard interpretation is false: i.e., that the lower section was laid down and then tilted, and that a long time later the upper section was deposited on top of it. Since millions of years are usually ascribed to such blocks of strata, there should be a difference in weathering apparent between the two blocks, but they show no such difference.

No. I said that the weathered rock was removed by mechanical erosion and that the lower rocks were covered shortly after erosion.

I didn't understand this, but let me venture a guess: do you mean that the lower rocks were eroded a long, long time ago, then shortly after that erosion the upper layers were deposited upon them, then the upper layers were buried, then they were exposed along with the lower layers that now make up a small cliff face, then weathering removed some upper layer rock by mechanical erosion. If that's not it would appreciate some clarification.

In fact, in the images of the unconformity there is no tectonic structure.

Not sure which images are meant.

There were pretty obvious fractures in the granite showing spheroidal weathering that would only occur during long periods of weathering. The purpose of this image was to show Faith a location where the underlying rocks actually were more weathered than the rocks overlying an unconformity. This is due to the fact that the granite was not being mechanically removed as it was weathered. I can see that my attempt to help the understanding of unconformities failed.

I might not get this, either, but anyway, here's the image:

My guess is that you're trying to explain that the weathering effects that caused the way the overlying sandstone and the underlying granite appear today was not what caused the embedded granite boulders to become mechanically weathered into spheroidal shapes.

Also, about this part:

But it was interesting for the fact that a depression in the granite was not filled by sand from the sandstone layers above, which to my mind shows that the depression occurred after the sandstone was in place.

An artifact of an oblique image.

About the depression Faith refers to that's about 1/3 of the way from the left side of the image and at the boundary between the sandstone and granite? That looks like it's really there to me. It looks like one of the granite boulders detached from the granite face and fell to the ground.

Faith's comment also highlights again her belief that holes and depressions in rock faces represent real cavities buried in the strata that have been revealed by erosion, rather than that they're just caused by pieces of rock breaking off and falling to the ground.

--Percy


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 Message 176 by edge, posted 01-04-2017 2:34 PM edge has responded

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 Message 180 by edge, posted 01-04-2017 4:31 PM Percy has responded

    
edge
Member
Posts: 3904
From: Colorado, USA
Joined: 01-09-2002
Member Rating: 4.3


Message 180 of 202 (796797)
01-04-2017 4:31 PM
Reply to: Message 179 by Percy
01-04-2017 3:58 PM


Re: a review
I didn't understand this, but let me venture a guess: do you mean that the lower rocks were eroded a long, long time ago, then shortly after that erosion the upper layers were deposited upon them, then the upper layers were buried, then they were exposed along with the lower layers that now make up a small cliff face, ...

That is the story. The critical part, however, is that the granite was not mechanically eroded fast enough to remove the weathered material.

I think that part of the problem here is the difference between weathering and erosion. This is a very important distinction.

... then weathering removed some upper layer rock by mechanical erosion.

Not necessarily part of the story. In fact, I might say that the erosion that exposes the cliff face may be artificial, i.e. a road cut or something to that effect.

Not sure which images are meant.

In this case, I'm referring to the original images of Siccar Point, showing the unconformity.

My guess is that you're trying to explain that the weathering effects that caused the way the overlying sandstone and the underlying granite appear today was not what caused the embedded granite boulders to become mechanically weathered into spheroidal shapes.

I am only referring to the weathered granite. The sandstone, being composed of quartz hardly weathers at all.

The boulders are formed by spheroidal weathering of granite along fractures. The 'boulders' are not yet actual boulders. But they will be some ages hence. They are also not yet mechanically eroded, though they are chemically weathered.

Does this help? I am so accustomed to reading the rock record that it's all second nature to me.

About the depression Faith refers to that's about 1/3 of the way from the left side of the image and at the boundary between the sandstone and granite? That looks like it's really there to me. It looks like one of the granite boulders detached from the granite face and fell to the ground.

Almost certainly. There is a shadow below the overhanging sandstone layer. Faith thinks that this is a depression in the granite, present before the sandstone was deposited.

And yes, Faith seems to think that this was an original depression in the granite. In that case, there are a lot of original depression visible in this image.


This message is a reply to:
 Message 179 by Percy, posted 01-04-2017 3:58 PM Percy has responded

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 Message 181 by Percy, posted 01-04-2017 4:58 PM edge has responded

  
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