Does the Eocene-Oligocene Transition show Life after the Global Flood?

[Job 33:6]

This says a lot about where you're coming from. The more I study the flood, the more I begin to understand just how complex it was.

Image B is interesting. Presumably those tilted rock layers are varying in degrees of hardness. Do you think it's weird that millions of years of gradual erosion appears to have sheered through all of them equally? You'd think the softer layers would have been eroded away much faster.

Of course a relatively sudden, extremely forceful event might be much less picky and sheer them all off equally. Just a thought.



How long does it take rock layers to harden in your estimation?
And also, semi-hardened rock layers can't be split apart?



Who believes they hardened instantaneously?



You mean rock layers heating up from a whole lot of force? What about that is a head-scratcher? If anything it leans towards catastrophic interpretation.



What are these magical laws that prevent dinosaurs from walking around and giving birth during the flood? There could have been all kinds of biological activity on temporarily exposed land masses.

And speaking of animal burrows, from what I gather there is much, much less of it than you would expect if these layers truly represted long-age ecosystems. However, if bioturbation occurred in temporary pulses between stages of inundation, it might explain the pattern better.




Probably because you're critiquing a cartoonish, simplistic view of the flood.



What exactly are you referring to here?

In some areas, more dense rock lasts longer than softer rock. However, there is no reason that, given enough time, layers would erode away equally, even if their densities do vary. But what should be noted in figure 2 is that you have extensional faulting, and so your rocks actually were not blasted away by compressional forces, rather they were stretched and pulled. Then when the stretching and pulling and turning was finished, then they were eroded.

So these rocks were, as you suggested, dense and hard prior to being eroded. And in order to erode through thousands of feet of solid rock, you either need an extraordinarily long time, or you need...essentially pure acid. But of course the oceans are not pure acid.

And this is just figure B. We still have all the other figures to go through. Which include but are not limited to:

Figure C: erosion and more deposition of thousands of feet of rock.

Figure D: More uplift and faulting, this time compressional.

Figure E: Extentional faulting ie a change in directional forces, and the faulting of further solidified rock.

Figure F: The erosion of thousands of feat of solidified rock...again. But this time, we have meanders, indicating that erosion was done by the river that rests within it...which is the Colorado river, which isnt made of pure acid, its just a regular river.

It didnt simply get blasted away, violently by acid waters (for which there is no evidence of), it was eroded away, casually by a regular everyday river (which is visibly evident).

You asked how long it might take rocks to harden. Well, there are different types of rocks present in the layers. You are looking at, millions of years. Go outside and pick up a rock, many are very dense, well compacted and lithified, and even super heated. Many form under tens of gigapascals of pressure and under temperatures of hundreds of degrees.

These are pressures and temperatures that really can only exist deep within the earth under the weight of kilometers of rock. These conditions cant exist at the surface of the earth, it just doesnt make any sense.

These are pressures so high, that anything on the surface of the planet would be...smashed into nothing and incinerated. Noah wouldn't even have a boat. Regular sedimentary rocks wouldnt even exist.

And no, the rocks were not "semi hardened", these were just regular rocks. There are things like fault gouge, breccias, pencil cleavage, propogating faults and cataclastic deformation, these are features that form in regular rock. And you cant even have certain rocks, such as igneous rocks, being "semi hardened" because if they were semi hardened, it would indicate a particular cooling point in which many of them wouldnt form.

Either the rock is cooled and has a particular chemistry, or it is still hot. Or you get partial melting, which again certain rocks would form in such environments.

Regarding sedimentary rocks, there are soft sediment formations, but the faults described above are not soft formations. There is nothing about them that indicates such, as far as physics and chemistry are concerned.

"What are these magical laws that prevent dinosaurs from walking around and giving birth during the flood? There could have been all kinds of biological activity on temporarily exposed land masses."

Remember, you just suggested that this flood produced temperatures hundreds of degrees high under gigapascals of pressure. No life could exist in such an environment. Let alone build nests and lay eggs and dig complex burrow systems and live at all. And these fossils and burrows and nests are found all over the planet in every period of time. So its not like there was just some random island hanging out in the middle of an apocalypse that dinosaurs lived peacefully on as if the planet wasnt 300 degrees celcius with atmospheric pressures beyond what is even possible in the universe.

And you suggest that there may be less bioturbation in older strata.

There is no question that lots of time existed for animals to hang out and to live their lives and to do what animals regularly do...all throughout the geologic column. Especially in the mesozoic in which the above strata depict in figures A through F.


And most flood advocates suggest that the flood occurred in perhaps a single year. So one has to wonder...in a single year, how did all of the above occur? It doesnt make any sense.

And time and time again, ive asked young earthers to try to make a specific timeline (perhaps month by month) in which all of this has occurred, and there is no logical way to do it.

 

[Job 33:6]

And the above even gets worse...a lot worse.

I always give the same example of an unconformity here in the Appalachian that rests between silurian and ordovician bedding. The ordovician bedding actually rests horizontally and unconformably against vertical silurian bedding.

It's one thing if the silurian were horizontal and the ordovician we're vertical. But it's actually an overturned or double turned angular unconformity in back to back periods in the paleozoic.

Which, young earthers have absolutely no way to explain the existance of such a thing.

And these things can be found in really any period you look. To suggest that such things formed in any short period of time doesn't make any sense and soft sediment just doesn't fold and fualt as hard rock does with fragmented breccias, thrust and reverse faults, propogating faults, etc.

If you have a mountain of wet sand for example, it won't fragment into sharp edged shards nor will it remain in parallel layers when turned on it's side. Also you wouldn't get lineation of things like phylosilicates in sheared rock. Sheared rock wouldn't exist at all if sediments or rock were soft because sediments would just roll off of one another if they were both hardened and lithified together.

 

[Job 33:6]

And you also get things like sheared oolids and trilobites and shellfish. That are sheared in synchrony with the rock body which contains them.

Soft or semi soft shells...they don't really exist in brachiopods or trilobites. Either it has a shell or it doesn't. Unless you're looking at some bizarre Burgess shale organism

So if you have sheared ductile deformation of fossils which are hard and otherwise bilaterally symetric, which is identical to sheared deformation of rock surrounding it...

Then they're both hard. And the shearing must occur under super high temperatures and pressures, else they would fracture (brittle deformation).

Ultimately, what I'm trying to say is that...it's obvious that these rocks we're individually deposited and individually lithified and individually folded and overturned. Which are events that, must take an extraordinarily long time. Far longer than any amount of time proposed by flood advocates.

 

[Ophiolite]

In some areas, more dense rock lasts longer than softer rock. However, there is no reason that, given enough time, layers would erode away equally, even if their densities do vary. But what should be noted in figure 2 is that you have extensional faulting, and so your rocks actually were not blasted away by compressional forces, rather they were stretched and pulled. Then when the stretching and pulling and turning was finished, then they were eroded.

So these rocks were, as you suggested, dense and hard prior to being eroded. And in order to erode through thousands of feet of solid rock, you either need an extraordinarily long time, or you need...essentially pure acid. But of course the oceans are not pure acid.

And this is just figure B. We still have all the other figures to go through. Which include but are not limited to:

Figure C: erosion and more deposition of thousands of feet of rock.

Figure D: More uplift and faulting, this time compressional.

Figure E: Extentional faulting ie a change in directional forces, and the faulting of further solidified rock.

Figure F: The erosion of thousands of feat of solidified rock...again. But this time, we have meanders, indicating that erosion was done by the river that rests within it...which is the Colorado river, which isnt made of pure acid, its just a regular river.

It didnt simply get blasted away, violently by acid waters (for which there is no evidence of), it was eroded away, casually by a regular everyday river (which is visibly evident).

You asked how long it might take rocks to harden. Well, there are different types of rocks present in the layers. You are looking at, millions of years. Go outside and pick up a rock, many are very dense, well compacted and lithified, and even super heated. Many form under tens of gigapascals of pressure and under temperatures of hundreds of degrees.

These are pressures and temperatures that really can only exist deep within the earth under the weight of kilometers of rock. These conditions cant exist at the surface of the earth, it just doesnt make any sense.

These are pressures so high, that anything on the surface of the planet would be...smashed into nothing and incinerated. Noah wouldn't even have a boat. Regular sedimentary rocks wouldnt even exist.

And no, the rocks were not "semi hardened", these were just regular rocks. There are things like fault gouge, breccias, pencil cleavage, propogating faults and cataclastic deformation, these are features that form in regular rock. And you cant even have certain rocks, such as igneous rocks, being "semi hardened" because if they were semi hardened, it would indicate a particular cooling point in which many of them wouldnt form.

Either the rock is cooled and has a particular chemistry, or it is still hot. Or you get partial melting, which again certain rocks would form in such environments.

Regarding sedimentary rocks, there are soft sediment formations, but the faults described above are not soft formations. There is nothing about them that indicates such, as far as physics and chemistry are concerned.

"What are these magical laws that prevent dinosaurs from walking around and giving birth during the flood? There could have been all kinds of biological activity on temporarily exposed land masses."

Remember, you just suggested that this flood produced temperatures hundreds of degrees high under gigapascals of pressure. No life could exist in such an environment. Let alone build nests and lay eggs and dig complex burrow systems and live at all. And these fossils and burrows and nests are found all over the planet in every period of time. So its not like there was just some random island hanging out in the middle of an apocalypse that dinosaurs lived peacefully on as if the planet wasnt 300 degrees celcius with atmospheric pressures beyond what is even possible in the universe.

And you suggest that there may be less bioturbation in older strata.

There is no question that lots of time existed for animals to hang out and to live their lives and to do what animals regularly do...all throughout the geologic column. Especially in the mesozoic in which the above strata depict in figures A through F.


And most flood advocates suggest that the flood occurred in perhaps a single year. So one has to wonder...in a single year, how did all of the above occur? It doesnt make any sense.

And time and time again, ive asked young earthers to try to make a specific timeline (perhaps month by month) in which all of this has occurred, and there is no logical way to do it.

First rate assembly of diverse, but relevant information. (Mind you, I have a soft spot for anything that includes Bowen's Reaction Series!)

 

[lifepsyop]

In some areas, more dense rock lasts longer than softer rock. However, there is no reason that, given enough time, layers would erode away equally, even if their densities do vary.

I'm assuming you meant to say "wouldn't"? If so, you're going to have to do a little better than simply asserting it.
I'm not saying it's impossible. Nature does weird, unexpected things. And it is certainly unexpected that slow, gradual erosion forces over long ages would act on both softer and harder rock equally.

In a long gradual scenario, one might expect softer sediments would erode more quickly than harder ones.

Furthermore it's unexpected that fully hardened rock would simply twist and bend like wet clay without resulting in huge fractures. Again, not saying it's impossible, just unexpected. However if the sediment layers were not completely dried and hardened when they began to be deformed, this is exactly the type of thing I'd expect to see.

But what should be noted in figure 2 is that you have extensional faulting, and so your rocks actually were not blasted away by compressional forces, rather they were stretched and pulled. Then when the stretching and pulling and turning was finished, then they were eroded.

So these rocks were, as you suggested, dense and hard prior to being eroded. And in order to erode through thousands of feet of solid rock, you either need an extraordinarily long time, or you need...essentially pure acid. But of course the oceans are not pure acid.

Are you talking about Figure F here? Phanerozoic rocks? I never suggested they had to be fully hardened.

As far as the erosion through many different layers of rock, what kind of effect do you think an entire ocean suddenly draining off the top of these sediments would have?

Here is just a minor example, the Missoula flood. Even evolutionists have argued that this amount of erosion might have occurred in a single catastrophic flood (within the evolutionary timeline of course), or rapid succession of floods occurring within years. And presumably being a post-flood catastrophe (Pleistocene rock layers), this would have been a tiny amount of water compared to the height of inundation during the global flood.

And this is just figure B. We still have all the other figures to go through. Which include but are not limited to:

Figure C: erosion and more deposition of thousands of feet of rock.

Figure D: More uplift and faulting, this time compressional.

Figure E: Extentional faulting ie a change in directional forces, and the faulting of further solidified rock.

Okay.

Figure F: The erosion of thousands of feat of solidified rock...again. But this time, we have meanders, indicating that erosion was done by the river that rests within it...which is the Colorado river, which isnt made of pure acid, its just a regular river.

So you're saying the evidence shows that the rock was eroded by moving water.

It didnt simply get blasted away, violently by acid waters

I never mentioned anything about "acid waters", though that is an interesting idea... and you have yet to put forth an argument on how it couldn't have been rapidly eroded by massive amounts of water. You're just nakedly asserting that it wasn't.

(for which there is no evidence of), it was eroded away, casually by a regular everyday river (which is visibly evident).

You're arguing that it's "self-evident" that a relatively tiny river carved through thousands of feet of hard rock creating massive canyons over millions of years? Sorry but that is an ambiguous interpretation at best... and more likely an extremely weak interpretation.

You asked how long it might take rocks to harden. Well, there are different types of rocks present in the layers. You are looking at, millions of years. Go outside and pick up a rock, many are very dense, well compacted and lithified, and even super heated. Many form under tens of gigapascals of pressure and under temperatures of hundreds of degrees.

These are pressures and temperatures that really can only exist deep within the earth under the weight of kilometers of rock. These conditions cant exist at the surface of the earth, it just doesnt make any sense.

These are pressures so high, that anything on the surface of the planet would be...smashed into nothing and incinerated. Noah wouldn't even have a boat. Regular sedimentary rocks wouldnt even exist.

And no, the rocks were not "semi hardened", these were just regular rocks. There are things like fault gouge, breccias, pencil cleavage, propogating faults and cataclastic deformation, these are features that form in regular rock. And you cant even have certain rocks, such as igneous rocks, being "semi hardened" because if they were semi hardened, it would indicate a particular cooling point in which many of them wouldnt form.

Either the rock is cooled and has a particular chemistry, or it is still hot. Or you get partial melting, which again certain rocks would form in such environments.

Regarding sedimentary rocks, there are soft sediment formations, but the faults described above are not soft formations. There is nothing about them that indicates such, as far as physics and chemistry are concerned.

I thought we were talking about sedimentary rock layers, not metamorphic. I'll have to revisit this one.

And are you talking about only pre-Cambrian strata?

"What are these magical laws that prevent dinosaurs from walking around and giving birth during the flood? There could have been all kinds of biological activity on temporarily exposed land masses."

Remember, you just suggested that this flood produced temperatures hundreds of degrees high under gigapascals of pressure. No life could exist in such an environment. Let alone build nests and lay eggs and dig complex burrow systems and live at all.

I didn't suggest anything like that. This is your own global flood hypothesis, apparently.

And these fossils and burrows and nests are found all over the planet in every period of time.
So its not like there was just some random island hanging out in the middle of an apocalypse that dinosaurs lived peacefully

I certainly don't think dinosaurs were "living peacefully" during various stages of a global catastrophe. Simply in a state of survival, perhaps moving into a previously inundated area that had been recently uplifted.

And you suggest that there may be less bioturbation in older strata.

No I didn't. Actually I might expect more in strata of wholly marine environments.

There is no question that lots of time existed for animals to hang out and to live their lives and to do what animals regularly do...all throughout the geologic column. Especially in the mesozoic in which the above strata depict in figures A through F.

Are you suggesting bioturbation cannot possibly happen quickly? I would actually expect a frenzied amount of burrowing from marine animals massively displaced from their regular seafloor environment and seeking shelter.

And most flood advocates suggest that the flood occurred in perhaps a single year.

Yes, though major portions of the Cenozoic strata may have been deposited after the year-long flood event.

So one has to wonder...in a single year, how did all of the above occur? It doesnt make any sense.

And time and time again, ive asked young earthers to try to make a specific timeline (perhaps month by month) in which all of this has occurred, and there is no logical way to do it.

Pardon me if I don't take your word for it. I see little more than naked assertions and ambiguous interpretation coming from you. Not to say it isn't interesting.

 

[Job 33:6]

Regarding your first response, it's not about the rate at which erosion occurs on varying rock types. It's about whether the rock is undergoing some form of deformation or uplift which would offset it from equilibrium and about whether the rock type is at an equilibrium.

Think about it, why wouldn't all the different rocks erode flush with the ground if they all had millions of years to erode away? For what reason would a rock indefinetly resist erosion and stick up into the sky?

View attachment 242983

No rock will stick into the sky forever if it is subjected to erosional forces such as those of wind...

Ok so now that we know that these rocks will erode toward the center of the earth, where would they stop eroding? The answer is that if you have wind, travelling along the surface of the earth, objects at a higher elevation than what is flush with the ground, will be subjected to erosional forces of a greater amount than rocks which do not stand in the way of those forces. This is why trees blow over in storms but the earth doesn't lift up into sky.

So the rocks erode down until they're flush with the ground. Or in the case of rock eroded by a river, they may be eroded down to the water table then they will reach equilibrium and it doesn't matter if it's a quartzite or rock made of marshmallows, they will erode to equal elevations regardless of density.

Once you understand this basic reality of erosion, then we can continue.

 

[Job 33:6]

"Furthermore it's unexpected that fully hardened rock would simply twist and bend like wet clay without resulting in huge fractures. "

Have you ever heard of ductile deformation?

It is well known that rocks take on ductile properties (like play doh or something pliable) when subjected to great amounts of heat and pressure (which are both common in the earth). If a rock is not at a certain temperature or does not have a certain pressure applied to it in certain directions, it will fracture (brittle deformation), however, ductile (non breaking) deformation is well understand and is known to be an occurrence in the earth and with rocks such as the ones in the image you posted.

 

[Job 33:6]

"Are you suggesting bioturbation cannot possibly happen quickly? I would actually expect a frenzied amount of burrowing from marine animals massively displaced from their regular seafloor environment and seeking shelter."

Frenzied animals arent going to be roaming around picking up tree branches and constructing nests. We even have pterosaurs foot tracks and tracks of ancient birds. What kind of a frenzied or fleeing pterosaur or bird waddles around on the ground?

There is nothing about tracks we find that indicate that animals were running around fleeing for their lives or frenzied. And honestly, if rock was being metamorphosed at hundreds of degrees celcius and eroded away at super fast rates by acid waters, then these animals wouldn't have had more than a fraction of a second to build their burrows or nests or burrow networks etc.

The fact is, regular everyday nests and not only that but mass collections of nests and complex multi-level burrow systems, is something we would expect to find if animals were regularly living life.

It is not something we would expect in the midst of a global flood in which rocks are being metamorphosed and asteroids are slamming into the planet and thousands of feet of solid rock is being instantaneously eroded away by acid waters.

And they must be acid waters because regular water, such as the water we know that exists on planet Earth, would take millions of years to erode through tens of thousands of feet of rock. Especially dense rock (based on rates of erosion that we see in the world today).

 

[Job 33:6]

"and you have yet to put forth an argument on how it couldn't have been rapidly eroded by massive amounts of water. "

You could take the worlds most powerful pump and blast a body of quartzite, and you would make no progress in eroding it away in your lifetime.

Unless the water chemically alters rock, such as perhaps in the case of limestone, water will not erode away 10 thousand feet of dense non reactive rock in any short period of time as you seem to believe.

Contrary to flood believers beliefs, this is physically impossible.

 

[Job 33:6]

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JF004099

Here is a paper in which estimates are made for rates of erosion of a fluvial system through sedimentary rocks. These rocks are not impervious shales, nor are they dense quartzites or other dense metamorphic rocks.

The researchers estimate incision rates at 1-3 millimeters per year.

https://pdfs.semanticscholar.org/3199/e10bd3d2df41c1c52245f3c54b24d5b0f8a1.pdf

Here is a paper that suggests rates of erosion peaking at 5 millimeters per year.

Needless to say, rivers do not blast through solid rock at any fast rate.



So, if we look at the images below. Mass wasting occurs in a linear path.

Notice in the above images, mass wasting is high energy and occurs in a linear path.
===================================================
Below we have low energy meanders.

In the picture above, we have a non linear, meandering path of a river. These rivers are low energy and sort of...aimlessly wander.They dont have enough energy to force a direct path of motion through rock, so they pick up small sediment, drop it off on a point bar, and cut the opposing wall creating a meander. This is what regular everyday rivers do, its well understood. And if you dont know what a meander is, read about it.
Meander - Wikipedia

This is not high energy, as it bows and ebbs aimlessly twists. High energy would blast in a single direction (as observed in the mass wasting images above), it would not alternate back and forth over and over again.

So we know this is low energy flow. As a matter of fact, we see many low energy rivers forming meanders today, so there is nothing odd about this concept. Casual rivers meander, its just what they do.

Now back to the start, if we have...lets say 6000 feet of rock, and said rock is eroded at an average rate of 5mm per year...

thats 1.8 million millimeters, divided by 5 per year....thats, 360,000 years.

Even if we quadrupled estimates, at 20 mm per year, we would still have 90,000 years.

in order for 6000 feet of rock to be eroded in a single year, we would need an erosion rate, literally 360,000 times greater than rates of erosion observed today.

Unless of course, the river was made of some sort of acid. But then still a river of acid would not meander, it would just burn a linear path.

And again, we know that these rocks were solidified prior to erosion, as non solidified rocks would not contain things like fault gouge and fault skarp, sharp brecciated fragmentation, propagating faults, sheared fossils and minerals and things of the like.

 

[Job 33:6]

With the above said, here is an aerial view of the dry falls/scablands and an aerial view of the grand canyon.

scablands^

Grand canyon^


Notice, the scablands have that same high energy linear path of mass wasting. There are no meanders, it is just a straight, high energy, bulldozing path, straight to the nearest river.

While the grand canyon looks entirely different in the form of a randomly turning, bowing, point bar depositing, dendritic, every day river.


If a river really had a super high amount of energy to blast away strata like at the scablands, that same water would not turn 180 degrees over and over and over again. Simple physics, an object in motion stays in motion, and the lithology of the canyon (the varying rock types) is not directing the meanders as the strata is laterally continuous. The meanders are purely the result of regular every day meander forming processes (the stream slows and drops sediment into a point bar, and cuts away on the opposing wall).

 

[Job 33:6]

Not only that, but the scablands deposits are limited to recent strata. The grand canyon has strata spanning for a much greater superpositional extent of strata.

They are completely different, temporally, geomorphologically, structurally, geochemically, lithologically, etc. Which is why pointing at the channeled scablands, is a poor and unreasonable response.

 

[Job 33:6]

"I thought we were talking about sedimentary rock layers, not metamorphic. I'll have to revisit this one.

And are you talking about only pre-Cambrian strata?"

The world consists of both.

Mesozoic and Cenozoic extension recorded by metamorphic rocks in the Funeral Mountains, California | GSA Bulletin | GeoScienceWorld

We find metamorphic rock of varying types and varying igneous rocks all throughout the column.

The above link is to research of mesozoic metamorphic rock that has undergone ductile deformation. This is superpositionally and temporally equivelant to rocks of the grand canyon, it is just in california, one state to the west.

Geologic development of the Cordilleran metamorphic core complexes | Geology | GeoScienceWorld

Here is a paper discussing metamorphic tertiary rock of arizona.

So you have to understand that there are mix of rock types, world wide and all throughout the geologic column.

"The Funeral Mountains metamorphic core complex, like so many of these complexes in the North American Cordillera, contains early ductile structures related to Mesozoic compressional tectonics that have been overprinted by structures related to later extension. The core-bounding detachment system formed in late Miocene time, and ductile extensional fabrics in its footwall have been viewed as evidence of a higher-temperature stage in the same event. Integrated structural analysis and geochronology, however, indicate that ductile fabrics with a transport direction similar to the northwest direction of movement on the detachment are part of an older extensional event of Late Cretaceous age. "

Do you understand what the paper is saying here? It is stating things that...could not be explained by a flood.

 

[lifepsyop]

Regarding your first response, it's not about the rate at which erosion occurs on varying rock types. It's about whether the rock is undergoing some form of deformation or uplift which would offset it from equilibrium and about whether the rock type is at an equilibrium.

Think about it, why wouldn't all the different rocks erode flush with the ground if they all had millions of years to erode away? For what reason would a rock indefinetly resist erosion and stick up into the sky?

View attachment 242983

No rock will stick into the sky forever if it is subjected to erosional forces such as those of wind...

But the question is not whether or not the harder rock could eventually be eroded. Of course it could.

The question is why don't we see evidence of further erosion, channeling, scouring of the softer sediments?

Why is each layer of differentiated rock so evenly sheered off? (angular unconformity in image B)

Ok so now that we know that these rocks will erode toward the center of the earth, where would they stop eroding? The answer is that if you have wind, travelling along the surface of the earth, objects at a higher elevation than what is flush with the ground, will be subjected to erosional forces of a greater amount than rocks which do not stand in the way of those forces. This is why trees blow over in storms but the earth doesn't lift up into sky.

Okay, for argument's sake let's assume they are all ultimately eroded flush with the ground equally. Then what? We're back to the original question. Why don't we then see evidence of a significant increase of erosion or abrasion in the softer sediment layers? (A "natural selection" of sediments if you will) They were exposed for millions of years weren't they? Why such uniformity?

You're just using a lot of words to restate the same assertion that it happens. I'm still waiting for an actual explanation.

So the rocks erode down until they're flush with the ground. Or in the case of rock eroded by a river, they may be eroded down to the water table then they will reach equilibrium and it doesn't matter if it's a quartzite or rock made of marshmallows, they will erode to equal elevations regardless of density.

Once you understand this basic reality of erosion, then we can continue.

Your little meandering river scenario river has a similar problem. Namely, why does this little meandering river choose to burrow itself through thick layers of harder rock beneath it when there is less resistance on the softer sediments beside it?

 

[Job 33:6]

Regarding the first topic again,

You said

"The question is why don't we see evidence of further erosion, channeling, scouring of the softer sediments?

Why is each layer of differentiated rock so evenly sheered off? (angular unconformity in image B)"

Rock will not weather down into the center of the earth. Erosional forces are mobile, flush with the ground. And so rock erodes, flush to the ground, whether it is highly dense rock, or less dense rock.


Its like running a slab of meat through a slicer, whether the meat has dense portions or soft portions, it cuts evenly because the cutting forces exist at a particular elevation.


Dense rock isnt going to necessarily protrude into the atmosphere at a higher elevation, if the dense rock has been eroded enough in which it is ran down to grade. The softer layers may erode flush with the ground first or slightly ahead of the denser layers or at a quicker rate. But ultimately, both dense and lesser dense layers will be equally eroded, flush with the ground.


Another example:

Lets say you build a sand castle at the beach. And the sand castle has a layer of mud and a layer of sand and a layer of gravel. If you let this castle sit, exposed to the atmosphere, then whether its water of the ocean or wind moving across the land, or glacial erosion from ice scouring through, each form of erosional force will erode both dense layers and soft layers equally and flush with the ground. They wont be unequally eroded unless the dense layer has not had the time to erode, or the erosional forces somehow erode deeper into the crust. Neither of which necessarily makes sense in this case, as the environment has had enough time to erode, and wind cant blow underground. So the rock slows or even stops in its rate of erosion flush with the ground.

 

[Job 33:6]

Actually, this also might help explain how erosion works...

So, you are asking why erosion would not continue underground... wind cant blow underground, so the erosion stops.

Even in figure F you can see that erosion doesnt really occur down into the bottom half of the figure. This is because...again, erosion wont just continue down into the center of the earth. It stops where erosive forces meet an equilibrium. Ice cant erode underground. It can scour the surface, but it cant go below what its own density allows. Same for water and wind. They dont erode underground, except in the case of limestone caves in which chemical dissolution results in water moving underground toward sea level. But wind and ice do not do this, and this requires that the environment be elevated above the water table (just a place where water rests underground).

 

[Job 33:6]

"Okay, for argument's sake let's assume they are all ultimately eroded flush with the ground equally. Then what? We're back to the original question. Why don't we then see evidence of a significant increase of erosion or abrasion in the softer sediment layers? (A "natural selection" of sediments if you will) They were exposed for millions of years weren't they? Why such uniformity?"

Maybe i should ask this, because i suppose there is a disconnect here.

What do you think we should see? Do you think we should see less dense rocks eroded into the earth?

 

[essentialsaltes]

Your little meandering river scenario river has a similar problem. Namely, why does this little meandering river choose to burrow itself through thick layers of harder rock beneath it when there is less resistance on the softer sediments beside it?

Given where the water is in the diagram, the answer seems obvious.

 

[Job 33:6]

"Your little meandering river scenario river has a similar problem. Namely, why does this little meandering river choose to burrow itself through thick layers of harder rock beneath it when there is less resistance on the softer sediments beside it?"

I thought this might have been what you were trying to get at.

Most rivers do not erode down into the earth. But we agree that, in the case of the grand canyon, the calorado river has eroded through several thousand feet.

The answer to why the grand canyon is different than say...the mississippi, is because of those same compressional and extensional forces that i keep bringing up over and over again.

Notice in figures B and F, erosion does not occur down into the bottom half of the figure. In Figure B, erosion occurs flush around the center of the figure. Then in figure F, erosion occurs again, roughly flush with the center of the figure. You asked why water would burrow itself into dense rock, as opposed to eroding softer rock around it, well the answer is that in Figure D, the land was uplifted by compressional forces. We call it the laramide orogeny. And with uplifted rivers, we have what we call erosional incision.

When you raise an object off of the ground, you give it something called gravitational potential energy. A higher state of energy forces something to erode more aggressively toward the center of the figure (sea level and flush with the ground).

And you can try this at home if you want. Get yourself a big box and put sand in it and put some water in it. Then lift and tilt the box and you will find that the water will gain energy and will erode away the sand faster as it begins to flow at a stronger velocity. Or you can go to a local museum and they have little setups where you can re-enact river erosion in sand boxes, its actually kind of fun.
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To summarize, the reason the river is cutting through hard rock rather than moving laterally, is because it is making its way toward the underlying water table, which just so happens to be below some of the denser rock. The reason it had to cut through all the above less dense layers is because the whole system was lifted into the atmosphere (above grade and above a flush level of the ground) by plate tectonics in the laramide orogeny.

Notice that the erosion of the upper 5000 feet of rock does not occur until after figure D in which those same layers had risen in elevation. Once risen in elevation, gravitational potential energy increases in the river, and there is now a vertical separation between the river and the water table. So the river has more energy and it wants to get back to its happy equilibrium, so it moves toward the water table. Its lateral motion is lessened once it enters the dense rock because the walls are dense, which is why lateral erosion of the canyon is greater in distance higher in the canyon. But by the time the water gets into the basement rock there, its just going straight down. Its not longer meandering, its cutting more like a knife through butter while simply retaining its pre existing meanders.

 

[lifepsyop]

Its like running a slab of meat through a slicer, whether the meat has dense portions or soft portions, it cuts evenly because the cutting forces exist at a particular elevation.

Interesting characterization. Yes, this was my original interpretation. The layers were cut uniformly by a rapid and extreme force.

Is something that looks like meat run through a slicer what you expect to see over millions of years of a gradually evolving lithosphere?