Register | Sign In


Understanding through Discussion


EvC Forum active members: 65 (9162 total)
5 online now:
Newest Member: popoi
Post Volume: Total: 915,815 Year: 3,072/9,624 Month: 917/1,588 Week: 100/223 Day: 11/17 Hour: 0/0


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   Evidence that the Great Unconformity did not Form Before the Strata above it
edge
Member (Idle past 1706 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(1)
Message 76 of 1939 (752953)
03-14-2015 8:48 PM
Reply to: Message 73 by Faith
03-14-2015 8:18 PM


Yes, and it can be easy to lose sight of its amazing size, but nevertheless in the canyon area, being right beneath that uplift, and right next to the canyon, suggests the effect I keep describing.
Faith, you never fail to entertain.
It is clear to everyone else here that no matter where the uplift occurred, the unconformity would be right underneath it.
Your observation is only relevant to this discussion because you say that it is.
But its huge extent also suggests that there should be other places where similar tectonic effects are in evidence.
Then please provide such evidence.
I'm talking about the stack of strata that used to exist above the Kaibab in the GC area, that no longer exists. It was as high as the Grand Staircase, and I suggest that it was strained by that mounded uplift (the Kaibab Uplift) when it occurred, since the highest strata would have stretched more over such a rounded uplift than the lower, and that it cracked, ...
Heh, heh, heh, ...
This is silly. So, you've got the post Permian rocks and the Precambrian rocks so strained that they are eroded away or highly sheared, and yet nothing happened to all of the rocks in between.
Are you being serious here?
... which was the beginning of the breakup of all that upper strata that then was washed away in the receding waters of the Flood, AND was the opening of what became the Grand Canyon. I think it's a very neat hypothesis myself.
It is a joke. It is a self-refuting fantasy.
The two miles of strata I'm referring to I just described above, the strata that were originally above the Kaibab over much of the Southwest area and into which the canyon was cut and out of which the Grand Staircase was carved. The "force" was the tectonic movement that caused the uplift and also the release of magma that is seen on the cross section under the GC and also at the far end of the Grand Staircase. I'd have to suppose that the same or other tectonic forces created the GU as far as it extends.
What were the dynamics of this 'Force'? When did gentle warps begin to generate the kind of strain you are talking about, that didn't affect the entire Paleozoic section?
Since you haven't yet explained them I don't know. I'll let you know after you've clarified.
It's pretty simple. When a fault cuts a rock the rock must be older than the fault. At the same time, when another structure (like an unconformity) cuts, terminates or dislocates a fault, that fault must be older than the feature that disrupts it.
Seems to be what everybody is saying, how the GU eroded flat and that created the surface for the strata to buld on.
Except that it was not entirely flat, as I explained earlier.
The problem I see is that I don't see how such an upthrust piece of hardened strata could erode away to flatness.
Some were not completely eroded. This is evident in your own sections.
You are missing my sarcasm directed at others here. Perhaps you need to notice more carefully the name at the upper right side of a post to whom it is addressed. In any case I agree with you that the uplift came later. I'm not entirely sure what you have in mind when you say "it warps the youngest rocks..."
The point is that whatever cause deformation of the GC Supergroup and eruption of the Cardenas Basalt did not affect the youngest rocks.
Uh yeah, that's the point of my argument that it wouldn't have eroded flat.
And it didn't. However, I know of no law that forbids that.
And there is plenty of time, your denial notwithstanding. There is actual hard evidence of long ages, all in opposition to your a priori beliefs.
So, what is your point?

This message is a reply to:
 Message 73 by Faith, posted 03-14-2015 8:18 PM Faith has replied

Replies to this message:
 Message 83 by Faith, posted 03-15-2015 8:01 AM edge has replied
 Message 95 by Faith, posted 03-15-2015 3:28 PM edge has not replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 77 of 1939 (752954)
03-14-2015 8:49 PM
Reply to: Message 74 by edge
03-14-2015 8:27 PM


Re: the Great uncomformity proves the Earth is old
... how the relation of the faults to the Supergroup proves it to be older than the strata.
You have it backward. The strata have to be there in order to be cut by faults.
I meant the strata above the G.U. I guess I have to call it the Paleozoic rocks.
I thought your evidence had to do with proving that the faults and formation of the G.U. preceded the laying down of the Paleozoic rocks, disproving my scenario in which they were already all there and all lifted at once.
The faults are terminated against the unconformity. This means the faults had to be there first. If not, then they would propagate through the unconformity. This is pretty basic geological interpretation.
Yes and I used the point myself in this thread somewhere. Thanks for the clarification.
But now I'm not sure which faults you are talking about.
Edited by Faith, : No reason given.

This message is a reply to:
 Message 74 by edge, posted 03-14-2015 8:27 PM edge has replied

Replies to this message:
 Message 79 by edge, posted 03-14-2015 8:56 PM Faith has replied

  
edge
Member (Idle past 1706 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


Message 78 of 1939 (752955)
03-14-2015 8:50 PM
Reply to: Message 75 by Faith
03-14-2015 8:41 PM


Re: Bible truth vs. Science
Once you have allowed the veracity of God's word to be brought into question, you have eroded the very foundation you need to make any claims at all for the primary issues of the Christian faith. If the Bible can't be believed in Genesis why should it be believed anywhere else?
Ah, I see. You are an absolutist and a Bible idolator. You don't worship your god.
And as a matter of sad fact, the gospel NEEDS Genesis to make sense, why we need a Savior, how God promised to send us a Savior.
According to Faith...

This message is a reply to:
 Message 75 by Faith, posted 03-14-2015 8:41 PM Faith has not replied

  
edge
Member (Idle past 1706 days)
Posts: 4696
From: Colorado, USA
Joined: 01-09-2002


(1)
Message 79 of 1939 (752956)
03-14-2015 8:56 PM
Reply to: Message 77 by Faith
03-14-2015 8:49 PM


Re: the Great uncomformity proves the Earth is old
I meant the strata above the G.U. I guess I have to call it the Paleozoic rocks.
The unconformity truncates those faults in the upward direction. The unconformity then post dates those faults and, by superposition, the Paleozoic System post dates the unconformity.
I thought your evidence had to do with proving that the faults and formation of the G.U. preceded the laying down of the Paleozoic rocks.
That is the unmistakable conclusion.
Yes and I used the point myself in this thread somewhere. Thanks for the clarification.
Then you have to agree that the faults which bound and preserve the GC Supergroup are older than the unconformity.
But now I'm not sure which faults you are talking about.
As I said, the ones that allow the GC Supergroup rocks to be preserved in down-dropped blocks. That faulting was clearly over by the time the Tapeats was deposited on the unconformity.

This message is a reply to:
 Message 77 by Faith, posted 03-14-2015 8:49 PM Faith has replied

Replies to this message:
 Message 82 by Faith, posted 03-15-2015 7:28 AM edge has replied

  
kbertsche
Member (Idle past 2131 days)
Posts: 1427
From: San Jose, CA, USA
Joined: 05-10-2007


(2)
Message 80 of 1939 (752959)
03-15-2015 12:22 AM
Reply to: Message 65 by Faith
03-14-2015 6:36 PM


Re: Bible truth vs. Science
This is sophistry. Science did develop from Christian principles, the principle that Nature follows the laws of a law-giving God. It certainly never meant that Science was on an equal footing with the Bible, it just meant that if Nature is lawful we have some hope of understanding it. There is certainly truth in Nature, but NOT NECESSARILY IN SCIENCE.
I completely agree with you that science is not on an equal footing with the Bible. These are two entirely different categories which cannot be directly compared. Science is a human interpretation of God's revelation of truth through nature, while the Bible is divine revelation of truth which must be interpreted by humans.
Nature and Scripture are both divine revelations of truth and are thus on an "equal footing" in terms of revealing truth. But they reveal very different things. To paraphrase Galileo, the Bible reveals how to go to heaven, while nature reveals how the heavens go.
Once you have allowed the veracity of God's word to be brought into question, you have eroded the very foundation you need to make any claims at all for the primary issues of the Christian faith. If the Bible can't be believed in Genesis why should it be believed anywhere else? And as a matter of sad fact, the gospel NEEDS Genesis to make sense, why we need a Savior, how God promised to send us a Savior.
I am not questioning the veracity of God's word, of course. Not even in Genesis. Rather, I am questioning--and rejecting--the YEC interpretation of God's word.

"Science without religion is lame, religion without science is blind." — Albert Einstein
I am very astonished that the scientific picture of the real world around me is very deficient. It gives us a lot of factual information, puts all of our experience in a magnificently consistent order, but it is ghastly silent about all and sundry that is really near to our heart, that really matters to us. It cannot tell us a word about red and blue, bitter and sweet, physical pain and physical delight; it knows nothing of beautiful and ugly, good or bad, God and eternity. Science sometimes pretends to answer questions in these domains, but the answers are very often so silly that we are not inclined to take them seriously. — Erwin Schroedinger

This message is a reply to:
 Message 65 by Faith, posted 03-14-2015 6:36 PM Faith has replied

Replies to this message:
 Message 81 by Faith, posted 03-15-2015 7:04 AM kbertsche has replied
 Message 84 by JonF, posted 03-15-2015 8:40 AM kbertsche has not replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 81 of 1939 (752962)
03-15-2015 7:04 AM
Reply to: Message 80 by kbertsche
03-15-2015 12:22 AM


Re: Bible truth vs. Science
Nature and Scripture are both divine revelations of truth and are thus on an "equal footing" in terms of revealing truth. But they reveal very different things. To paraphrase Galileo, the Bible reveals how to go to heaven, while nature reveals how the heavens go.
The written word can actually reveal things directly -- that's what "revelation" means. Nature doesn't reveal anything to us about itself or even about God in our fallen condition, it's utterly opaque to us normally, and science is the only method that can interpret it. And then it took millennia before science even developed as a useful tool and centuries after that for it to reveal anything consistently trustworthy. Nature may be on an equal footing as far as its being Gods work goes, but we can't read it at all as we can read God's written word.
You say you aren't denying Genesis, just the YEC interpretation of Genesis. But that can only mean you accept one of the interpretations that allows for evolution and the old earth -- the "gap" theory or some such? As I said, evolution requires death before the Fall, that's a direct contradiction of scripture and if you accept it you are contradicting the Bible, not just a human interpretation of the Bible. The Old Earth is also a contradiction, especially since it justifies the idea of evolution, but also because there is no way to compute the Old Earth from scripture itself, again contradicting not just a human interpretation but scripture itself.
If death preceded the Fall then death is natural and not a corruption of life due to sin. Why do we need a Savior from something that's natural and inevitable? He came to save us from sin which is a violation of God's law and from death which is a violation of nature brought about by sin. I don't see any way you can shoehorn in either of these theories without doing violence to God's word and to the gospel.
And

This message is a reply to:
 Message 80 by kbertsche, posted 03-15-2015 12:22 AM kbertsche has replied

Replies to this message:
 Message 85 by kbertsche, posted 03-15-2015 8:44 AM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 82 of 1939 (752963)
03-15-2015 7:28 AM
Reply to: Message 79 by edge
03-14-2015 8:56 PM


Re: the Great uncomformity proves the Earth is old
I meant the strata above the G.U. I guess I have to call it the Paleozoic rocks.
The unconformity truncates those faults in the upward direction. The unconformity then post dates those faults and, by superposition, the Paleozoic System post dates the unconformity.
I still don't know what faults you are talking about but I'm not sure it matters.
However, if the Paleozoic strata post-date the G.U. simply by superposition, that is, simply because it's beneath the Paleozoic system, that refers well enough to the strata the G.U. is composed of, all that being already there before the Paleozoic layers were formed, but it really doesn't prove that the unconformity itself, the tilted blocks of strata, formed before the Paleozoic system did. Unless I'm missing something in what you're saying. Surely it's not uncommon for there to be underground movements of rock that in themselves predate upper rock, while the movement and repositioning of the lower rock are then more recent than the upper rock. Earthquakes reflect such underground shifts, right?
I thought your evidence had to do with proving that the faults and formation of the G.U. preceded the laying down of the Paleozoic rocks.
That is the unmistakable conclusion.
Except for what I say above. Unless, again, I'm missing something in what you said.
Yes and I used the point myself in this thread somewhere. Thanks for the clarification.
Then you have to agree that the faults which bound and preserve the GC Supergroup are older than the unconformity.
That doesn't seem to be a problem although I still don't know what faults you are talking about, and I don't understand what you mean by "bound and preserve the Supergroup."
But now I'm not sure which faults you are talking about.
As I said, the ones that allow the GC Supergroup rocks to be preserved in down-dropped blocks. That faulting was clearly over by the time the Tapeats was deposited on the unconformity.
I don't see faults on most of the cross sections and still don't know what you are referring to. I also don't know what you mean by "allow the GC Supergroup rocks to be preserved in down-dropped blocks." I have to guess that the blocks are considered to have been lowered as mentioned before but I don't know why this is thought, what the evidence is, or what the implications are of this down-dropping. Or how the faulting relates to it and "preserves" it.

This message is a reply to:
 Message 79 by edge, posted 03-14-2015 8:56 PM edge has replied

Replies to this message:
 Message 91 by edge, posted 03-15-2015 10:38 AM Faith has replied

  
Faith 
Suspended Member (Idle past 1444 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 83 of 1939 (752964)
03-15-2015 8:01 AM
Reply to: Message 76 by edge
03-14-2015 8:48 PM


Yes, and it can be easy to lose sight of its amazing size, but nevertheless in the canyon area, being right beneath that uplift, and right next to the canyon, suggests the effect I keep describing.
Faith, you never fail to entertain.
It is clear to everyone else here that no matter where the uplift occurred, the unconformity would be right underneath it.
Then I guess I'm the dunderheaded exception, but I don't get it except on the scenario I've given which you disagree with. To have to be right underneath the uplift means it has to be related to the uplift somehow, but unless it was also affected in the uplift as I'm suggesting it was, then I don't see how you would regard it as anything but a completely random or accidental fact that it happens to be right beneath the uplift.
Your observation is only relevant to this discussion because you say that it is.
???
But its huge extent also suggests that there should be other places where similar tectonic effects are in evidence.
Then please provide such evidence.
Just a guess of mine that seemed logical. But perhaps some time you could give some kind of account of the Great Unconformity as it is found in other places besides the GC? That would be very interesting.
I'm talking about the stack of strata that used to exist above the Kaibab in the GC area, that no longer exists. It was as high as the Grand Staircase, and I suggest that it was strained by that mounded uplift (the Kaibab Uplift) when it occurred, since the highest strata would have stretched more over such a rounded uplift than the lower, and that it cracked, ...
Heh, heh, heh, ...
This is silly. So, you've got the post Permian rocks and the Precambrian rocks so strained that they are eroded away or highly sheared, and yet nothing happened to all of the rocks in between.
Let me get something clear: you aren't denying that there WAS such a stack of post Permian rocks above the canyon area?
Do you also accept that the post-Permian rocks were severely eroded, forming the Grand Staircase and scouring off the Kaibab plateau?
Are you being serious here?
Very. If all that post-Permian rock could have been so catastrophically eroded as we can see on that main cross section of the area, what's the problem with the possibility that the uplift put strain on the upper layers of that rock? At two miles above the Permian those uppermost strata would be stretched a great deal by such an uplift. This doesn't seem reasonable to you?
... which was the beginning of the breakup of all that upper strata that then was washed away in the receding waters of the Flood, AND was the opening of what became the Grand Canyon. I think it's a very neat hypothesis myself.
It is a joke. It is a self-refuting fantasy.
Seems quite reasonable to me. The strain is reasonable to begin with, and the breaking up of the upper strata is reasonable based on the strain which would stretch and crack the sediments. If it did all occur in the receding phase of the Flood you then have a lot of water as the mechanism for producing all that very visible erosion, including very likely the Grand Canyon itself.
Perhaps you are just so used to thinking in terms of slow processes this hits you as too alien to consider?
The two miles of strata I'm referring to I just described above, the strata that were originally above the Kaibab over much of the Southwest area and into which the canyon was cut and out of which the Grand Staircase was carved. The "force" was the tectonic movement that caused the uplift and also the release of magma that is seen on the cross section under the GC and also at the far end of the Grand Staircase. I'd have to suppose that the same or other tectonic forces created the GU as far as it extends.
What were the dynamics of this 'Force'? When did gentle warps begin to generate the kind of strain you are talking about, that didn't affect the entire Paleozoic section?
Well, first of all, you too believe the uplift occurred after all the strata were in place, correct? That suggests that you believe it possible for the strata to have remained intact through that uplift since it clearly IS intact. Now perhaps you think that's because it occurred more gently and slowly than I have in mind? Actually even if it did, ultimately the upper strata so high above the Permian would have had to undergo strain from being stretched more than the lower strata.
I think the immense weight of all the strata would have held it together by compressing it when the uplift occurred due to tectonic force from beneath. It wouldn't have had to be abrupt but it would have had to be extremely powerful, pushing up the entire stack three miles deep. The continuous relentless pushing of a continental collision seems powerful enough and not necessarily abrupt, adequate to the scenario I have in mind. I'm not imagining anything particularly abrupt or violent, just powerful enough pressure to push the strata of the Supergroup into an unconformity and raise the whole stack of strata above.
I'm going to have to break off answering this post and come back to it.
Edited by Faith, : No reason given.
Edited by Faith, : No reason given.

This message is a reply to:
 Message 76 by edge, posted 03-14-2015 8:48 PM edge has replied

Replies to this message:
 Message 86 by Pressie, posted 03-15-2015 8:49 AM Faith has replied
 Message 93 by edge, posted 03-15-2015 11:15 AM Faith has replied

  
JonF
Member (Idle past 168 days)
Posts: 6174
Joined: 06-23-2003


Message 84 of 1939 (752965)
03-15-2015 8:40 AM
Reply to: Message 80 by kbertsche
03-15-2015 12:22 AM


Re: Bible truth vs. Science
I am not questioning the veracity of God's word, of course. Not even in Genesis. Rather, I am questioning--and rejecting--the YEC interpretation of God's word.
Faith has explicitly declared that her intrepretation of the Bible is infallible.

This message is a reply to:
 Message 80 by kbertsche, posted 03-15-2015 12:22 AM kbertsche has not replied

Replies to this message:
 Message 98 by Faith, posted 03-15-2015 3:45 PM JonF has replied

  
kbertsche
Member (Idle past 2131 days)
Posts: 1427
From: San Jose, CA, USA
Joined: 05-10-2007


Message 85 of 1939 (752966)
03-15-2015 8:44 AM
Reply to: Message 81 by Faith
03-15-2015 7:04 AM


Re: Bible truth vs. Science
Nature doesn't reveal anything to us about itself or even about God in our fallen condition, it's utterly opaque to us normally, and science is the only method that can interpret it.
Really? Then why does Paul say that nature reveals truths about God so plainly and so clearly that fallen man is without excuse for rejecting God (Rom 1:18-20)? What you say above disagrees with Paul!
If death preceded the Fall then death is natural and not a corruption of life due to sin. Why do we need a Savior from something that's natural and inevitable? He came to save us from sin which is a violation of God's law and from death which is a violation of nature brought about by sin.
I believe that death of animals is indeed natural. They don't sin so they don't need a Savior. Death only of man is a consequence of sin (Rom 5:12ff).

"Science without religion is lame, religion without science is blind." — Albert Einstein
I am very astonished that the scientific picture of the real world around me is very deficient. It gives us a lot of factual information, puts all of our experience in a magnificently consistent order, but it is ghastly silent about all and sundry that is really near to our heart, that really matters to us. It cannot tell us a word about red and blue, bitter and sweet, physical pain and physical delight; it knows nothing of beautiful and ugly, good or bad, God and eternity. Science sometimes pretends to answer questions in these domains, but the answers are very often so silly that we are not inclined to take them seriously. — Erwin Schroedinger

This message is a reply to:
 Message 81 by Faith, posted 03-15-2015 7:04 AM Faith has replied

Replies to this message:
 Message 87 by jar, posted 03-15-2015 9:14 AM kbertsche has replied
 Message 99 by Faith, posted 03-15-2015 3:49 PM kbertsche has not replied

  
Pressie
Member
Posts: 2103
From: Pretoria, SA
Joined: 06-18-2010


Message 86 of 1939 (752967)
03-15-2015 8:49 AM
Reply to: Message 83 by Faith
03-15-2015 8:01 AM


Faith writes:
Just a guess of mine that seemed logical. But perhaps some time you could give some kind of account of the Great Unconformity as it is found in other places besides the GC? That would be very interesting.
In the Vanrhynsdorp Group in my country and the Nama Group in Namibia there's absolutely no geological unconformity found in the "rocks" between the Precambrian Namibian Era and the Cambrian period. Those sedimentary rocks straddle the boundary between the Precambrian and the Cambrian Period. No unconformity between Cambrian and Precambrian found there.
Blows magic global floods during that time out of the water.

This message is a reply to:
 Message 83 by Faith, posted 03-15-2015 8:01 AM Faith has replied

Replies to this message:
 Message 102 by Faith, posted 03-15-2015 4:15 PM Pressie has not replied

  
jar
Member (Idle past 394 days)
Posts: 34026
From: Texas!!
Joined: 04-20-2004


Message 87 of 1939 (752968)
03-15-2015 9:14 AM
Reply to: Message 85 by kbertsche
03-15-2015 8:44 AM


Re: Bible truth vs. Science
I believe that death of animals is indeed natural. They don't sin so they don't need a Savior. Death only of man is a consequence of sin (Rom 5:12ff).
I wish you would start a thread on that in one of the F&B forums since neither your position or Faith's position or even Paul's position seem to make any sense Biblically.

Anyone so limited that they can only spell a word one way is severely handicapped!

This message is a reply to:
 Message 85 by kbertsche, posted 03-15-2015 8:44 AM kbertsche has replied

Replies to this message:
 Message 113 by kbertsche, posted 03-15-2015 6:51 PM jar has seen this message but not replied

  
Percy
Member
Posts: 22391
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


(5)
Message 88 of 1939 (752970)
03-15-2015 9:17 AM
Reply to: Message 45 by Faith
03-14-2015 12:45 PM


Faith writes:
I recalculated the rise of the mounded area. It's a rise of 160 feet in one mile. Pretty shallow but still I don't see how layers are going to follow its contour.
No one is claiming the uplift was already present when the layers were deposited, but that's only a 3% slope. Take a foot-long ruler, lie it on a table surface, put a pencil under one end. That's a 3% slope. Layers will have no problem accumulating on such a mild slope.
You said this in Message 44:
Unfortunately for you all the evidence shows that the Great Unconformity was laid down before the layers above it
Except the evidence I'm giving.
You're not providing any evidence. Obviously you think you are, so what is it? In your Message 1 you didn't describe any new evidence, just "THINGS TO NOTICE" that were incredibly obvious. Not only had everyone already noticed them, they've been discussed, with you, in previous threads.
As all diagrams clearly show, the top of the tilted G.U. was eroded fairly flat before more layers were deposited atop it.
I always find that idea as absurd as the idea that the strata would conform to the slope of a hill.
That's your problem if you find absurd the process of erosion gradually flattening landscapes. It's a process we can see occurring in the world today, and one we find has happened enumerable times in the past.
Normal erosion doesn't reduce sharply tilted rock to a flat plain in my experience.
Erosion erodes whatever is there, whether it's been tilted from its original orientation or not. Look at this diagram of the formation of a basin and range again:
Look at the last step in the process, the bottom drawing. This is a typical basin and range. The highest parts of the exposed top portions of the tilted blocks form mountain ranges. The lowest parts of the exposed top portions of the tilted blocks form valleys. Here's my own rendition of the last stage in the formation of basin and range:
This next diagram shows what happens as the forces of weathering begin to work on the new landscape. The topmost parts of the layers that are sticking up begin to erode away (the mountains) and the eroded material accumulates in the lowest regions (the valleys):
The weathering of the high regions and the transport of the eroded material by the forces of wind and water into the lower regions continues:
The exposed top layers of the tilted blocks are eroded away until they are completely gone, exposing the layers below which are also eroded, eventually leaving only a flat plain atop tilted layers.
If the region should subside and become submerged then layers will begin accumulating atop them:
If the region is again uplifted and subjected to erosion and if a river flows through the region as it is uplifted then a canyon will be cut into the layers:
This is what happened at the Grand Canyon.
--Percy
Edited by Percy, : Fix quote.
Edited by Percy, : Typo.

This message is a reply to:
 Message 45 by Faith, posted 03-14-2015 12:45 PM Faith has not replied

Replies to this message:
 Message 89 by ThinAirDesigns, posted 03-15-2015 9:28 AM Percy has seen this message but not replied

  
ThinAirDesigns
Member (Idle past 2373 days)
Posts: 564
Joined: 02-12-2015


Message 89 of 1939 (752972)
03-15-2015 9:28 AM
Reply to: Message 88 by Percy
03-15-2015 9:17 AM


As the new guy to geology, that was AWESOME Percy. Thanks
JB

This message is a reply to:
 Message 88 by Percy, posted 03-15-2015 9:17 AM Percy has seen this message but not replied

  
Percy
Member
Posts: 22391
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


(1)
Message 90 of 1939 (752973)
03-15-2015 9:37 AM
Reply to: Message 48 by Faith
03-14-2015 12:52 PM


Faith writes:
Yes, but I didn't have the evidence of the order of things at the G.U. level, I didn't see how the layers would have butted up against it if deposited in the order usually accepted.
If by "butted up against it" do you mean the way your diagram shows new layers forming adjacent to the supergroup layers and butting up against them (Your diagram is mislabeled, by the way - what you've labeled the Great Unconformity is actually layers of the supergroup. The Great Unconformity is at the boundary at the very top of the supergroup layers. That boundary is at an angle to the supergroup layers themselves, and your diagram fails to show that, too.):
If this is what you mean, there is no evidence that anything like this ever happened. The Vishnu Schist adjacent to the supergroup layers were already there when the supergroup layers were deposited. When the stretching of the continent caused all the faulting that formed the blocks of basin and range then the lowest supergroup layers slipped to be adjacent to older Vishnu Schist layers. What we see in the region of the Grand Canyon you're looking at is just the very lowest and oldest layers of the supergroup.
See my previous Message 88 for a detailed illustration of how the layers at the Grand Canyon formed.
--Percy

This message is a reply to:
 Message 48 by Faith, posted 03-14-2015 12:52 PM Faith has replied

Replies to this message:
 Message 100 by Faith, posted 03-15-2015 3:58 PM Percy has seen this message but not replied

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2023 by EvC Forum, All Rights Reserved

™ Version 4.2
Innovative software from Qwixotic © 2024