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Author Topic:   Deposition and Erosion of Sediments
AdminNosy
Administrator
Posts: 4754
From: Vancouver, BC, Canada
Joined: 11-11-2003


Message 91 of 127 (195745)
03-31-2005 1:50 PM
Reply to: Message 90 by Jazzns
03-31-2005 11:20 AM


SubTitle
As a help to all readers could you observe that discrepancy between the subtitle on your post (Re: Deposition on dry land) and the content of your post ("Inferences about past states and events"?)?

This is a general hint the the anterlered one seems to have given up on.


This message is a reply to:
 Message 90 by Jazzns, posted 03-31-2005 11:20 AM Jazzns has replied

Replies to this message:
 Message 92 by Jazzns, posted 03-31-2005 1:55 PM AdminNosy has not replied

  
Jazzns
Member (Idle past 3225 days)
Posts: 2657
From: A Better America
Joined: 07-23-2004


Message 92 of 127 (195748)
03-31-2005 1:55 PM
Reply to: Message 91 by AdminNosy
03-31-2005 1:50 PM


Re: SubTitle (changed)
Good call Nosy. I'll watch that in the future.

This message is a reply to:
 Message 91 by AdminNosy, posted 03-31-2005 1:50 PM AdminNosy has not replied

  
Faith 
Suspended Member (Idle past 758 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 93 of 127 (196254)
04-02-2005 4:49 PM
Reply to: Message 29 by Jazzns
03-17-2005 1:11 PM


Re: Hopefully Helpful Info About Sedimentation
Hello Jazz. I will try to get back to this thread, starting with your message #29 as you requested.

My problem is with the enormous time frame. The idea that ANYTHING could sit still for 50 million years is simply preposterous to my mind. How can ANYTHING "subtle" happen in a 50-million year period? Hurricanes alter seacoasts and beaches, tornados move tons of stuff from here to there, one good rain causes mudslides all over California that rearrange local landscapes drastically, not subtly, and destroy houses; all in one year; but the redwall limestone stays in place for 50 million years even in the phase where it's quietly sedimenting away and not yet lithifying?

quote:
That is part of the problem. Over 50 million years, things like a hurricane ARE subtle events.

You are absolutely not getting it. You need to predict the accumulated effects of our normal weathering patterns over such an enormous period of time. Such events are not subtle at all if the principle of uniformitarianism is correct and they happen at the rate experienced in human history.

Figure up the normal pattern of such events, of hurricanes, tornadoes, earthquakes, mudslides, rock slides, volcanoes, forest fires, tidal waves, rainstorms, snowstorms, windstorms, floods, then add in the hundred-year record-breaking versions that are also part of the pattern, then multiply by whatever millions of years it is postulated that a particular stratum took to form. (Assuming that anybody agrees that any of them were ever above water for so long, which in fact may not be the case anyway -- but this is a digression).

Most of these normal events have been known to alter the topography of the land. It is within historical time that such events may appear insignificant, not over millions of years, and insignificant to us because they don't happen everywhere at once, we are used to them and have learned to deal with them more or less, at least in some parts of the world. But they would not be dwarfed at all by millions of years, as you claim, but on the contrary, multiplied to enormous effects. Every year the world experiences a round of them and we manage to recover one way or another, even with great loss of life in some cases, but recover nevertheless, and sometimes we note that the terrain has changed, but we pick up and go on. Just multiply these yearly effects by millions.

quote:
Over the span of your life have any of the hurricanes removed the Florida everglades or the beaches in the southeast coast?

No, of course not, and your focusing on this shows you are missing the point. Each storm moves things around to some extent. Give it millions of years and see what moving things a little every year adds up to.

quote:
Did El Nino destroy the Mojave Desert? Sure it might mix stuff up but it is still there.

Uh huh, but as usual you are not getting the point, that small changes multiply greatly over millions of years.

quote:
These "events" do not stop deposition and over the course of time the average will be positive deposition.

But not your nice regular even flat deposition which is what we see in the strata.

quote:
No one is claiming that everything must sit still for 50 million years. All it has to do is sit sill long enough for more stuff to pile on top of it on average. Once it is buried then either it gets further buried or it gets eroded. The stuff that gets eroded is carted off to some other location where it may or may not get buried there. It has to go somewhere and it WILL and up someplace where it is less and less likely to be eroded even if it has to travel all the way to the bottom of the ocean.

Yes, but again these processes cannot be expected to build up regular horizontal layers of the sort we see in the strata. They shift things around, they do not allow neat layers to form.

How long did it take for the sediment to accumulate during that 50 million years before the next layer of completely different sediment started accumulating? You guys are all talking about geological processes that you see occurring in human time, such as sedimentation in rivers, and extrapolating to millions of years of time as if it made sense to do that.

quote:
It does make sense because we are not just looking at the stuff that gets dropped out of the Mississippi river while we are watching it. We know that the Mississippi river delta is composed of material that the river has weathered from upstream. We can look at the sedimentation rate today and we can drill and see all the layers that have been deposited over the lifetime of the delta. To say that these layers in particular are from a different source other than the delta is rediculous because they are the same as the ones we can watch being deposited today. Therefore we can look at the whole Mississippi delta and all the layers it has produced ever.

I'm not getting this picture. You aren't describing these layers, their contents, their thicknesses, comparing them to the Geo Column. You have to show that the rate of deposition and the distinctions between layers could explain the buildup of the Geo Column over millions of years. And who said anything about these layers being "from a different source other than the delta" anyway?

quote:
When we practice geology on these layers we are looking at something that is "current" with respect to geologic time. The Mississippi delta system is "live" so we know a lot about the characteristics of the sediment in the delta. Then when we find layers buried somewhere else where there is not a river but has the same characteristics as the layers of the Mississippi delta we can hypothesize that there was once a delta there. Then we search the area to try to find evidence of an ancient river and when we do it confirms our ability to take our current knowledge that we gathered from the current "live" formation and apply it to something different.

Sure, but many layers building up in a delta in historical time doesn't exactly commute to layers built up over millions of years as seen in the Geo Column. The best you can extrapolate is that water deposition is likely the cause.

And since you are clear that the deposition is of sediments brought down from eroded upstream rocks and terrain, how does the idea of "landscapes" ever come up with regard to any of the strata as explained by water deposition anyway?

quote:
This applies to many other aspects of geology. We can watch deserts today and how they work. We can watch sand dunes and cut into them to see what they look like on the inside. We can see that they are one big heap of sand with internal cross-bedding. A desert is a "live" geologic system even if we never saw the sand that is at the bottom of dune be deposited. Then when we find the Coconino sandstone that just looks like a lithified version of a sand dune we have strong evidence that the Coconino sandstone came from a desert.

You can say pretty justifiably that the Coconino sandstone was formed from sand that was tumbled as dune sand is tumbled, but going on to say that that layer represents a millions-of-years-in-the-making "landscape" of dunes built on top of a millions-of-years-in-the-making "landscape" of clay deposition that became shale, on down through the strata... You know, I know I keep repeating myself, and I know it irritates people here to no end, but every now and then I just have to stop and think about what these layers actually LOOK like in the Grand Canyon and elsewhere, and the Geo timeframe explanation of millions of years again hits me as a gigantic hoax. "Landscapes?" Under water, above water, whatever, it does not compute. OK, I'm doing my best to put into words why. Excuse the digression please.

How deep is the sedimentation in a river? can it possibly compare to the thicknesses of the strata? And since you say below that those same sediments are re-eroded and re-deposited, how can THAT be extrapolated to the neat thick layers of the canyon walls?

quote:
Well, first off the canyon sediments were not deposited by a river so there can be no extrapolation to the same kinds of things we see in the GC. River deposits are very different from ocean deposits so your request for a correlation between the sediment in the GC and river sediments is unwarrented.

The point was that when I'd point out how the strata in the canyon couldn't have built up over millions of years somebody would point to a river as an example of how it could, NOT to say that's the cause of the Grand Canyon itself -- neither I nor they made that mistake as far as I know -- but to say that this is a PROCESS OF LAYER-MAKING THAT CAN BE EXTRAPOLATED to the formation of the strata in the Geo Column in general. My answer is that the process may help explain it but not the time factor. In any case, as I recall, it look quite a while before anyone even said that the Grand Canyon was formed in the ocean, and some appeared to be unsure about how much of it was formed that way. If any strata lower in the column appear to be eroded, that also remains to be explained in terms of ocean deposition.

It appears to me that ALL the horizontal -- or previously horizontal and still parallel -- strata wherever they are found MUST have been formed in water, but so far nobody has confirmed that.

In a river, the re-erosion and re-deposition happens as the river carries material down stream. Rivers tend to erode things but they also leave evidence of their erosion and when they flood. The process of re-erosion and re-deposition creates ripple marks in some rivers that get preserved if that sediment lithifies. This is similar to the cross-bedding in desert sandstone. It is an indicator that the sediment was being moved around by some process (wind or water) before it was lithified. It directly shows that sediment in question was exposed to weathering yet not enough to overcome the amount of sediment that entered the system which allowed it to be buried.

And yet you ignore other processes such as big changes in the landscape within a year or certainly a human lifetime, and apparently don't extrapolate THOSE things to the millions of years.

Big changes like what?

Mud slides? There are tons of preserved examples of ancient mud slides. Sometimes that is the best way to bury some dry land geologic features. Polystrate trees and such are often the result of some local catastrophic event such as a mud slide that quickly buries something. These things are preserved in the geologic record. IN the case of the GC, mud slides are rare at the bottom of the ocean.

Volcanoes? These are also preserved in the geologic record and even in the GC there is a disruption of sedimentation due to a volcano erupting and leaving behind its ash and igneous rock. But it buried the stuff that was already there. It did not remove it.

Tornadoes/Hurricanes? Sure these things cause weathering but are actually minor in comparison to the overall time that sediment is being deposited. Also, consider that the material removed by these events still ends up somewhere and often it is probably nearby. SO when you look at a formation that spans hundreds upon hundreds of square miles, the fact that this was in one spot but is now a hundred miles away as a part of the same feature is moot.

Such processes would certainly obliterate a layer of sediment over millions of years (if not underwater).

No actually either they would help preserve the layers or at worst are a minor disruption in the net sedimentation which probably only serve to move stuff around a bit.

Somebody says oh but it was covered up (underwater or not underwater?). But with what?

Sediment on the surface is subject to weathering. If the weathering tends to dump more stuff out then take stuff away then material will pile up and be buried. This is observable both in real time and as a part of "live" geologic system.

All I'm going to say to the entire quotation exchange above is that you are not addressing the effect I'm saying all these processes would have on the strata DURING THEIR MILLIONS OF YEARS OF FORMATION, when the sediments were still presumably quite moveable. You keep imagining things happening AFTERWARD, piling on top of the formation and so on, but remember, the formation itself was presumably, based on the timetable idea, in the process of forming for millions of years and presumably, therefore, subject to all these normal processes over those millions of years. You say there are records of mudslides. Fine. But surely a mudslide would have destroyed any layer in the process of forming before it slid -- not something piling on TOP of it, but the layer itself sliding. And if a mudslide occurred on top of a layer not yet formed then it would have interrupted it anyway. And how many of these do you suppose would have happened in millions of years here and there? Combined with all the other kinds of disturbances I can't see any strata forming at all.

Except underwater of course.

Yes, as you say, "SEDIMENT ON THE SURFACE IS SUBJECT TO WEATHERING." Thank you. Now extrapolate that TO MILLIONS OF YEARS OF extremely slow buildup on that surface which weathering would affect to a depth greater than the deposition depth implied by those millions of years and try to figure out how a layer stayed a layer for even a tenth of that time.

UNLESS IT WAS UNDER WATER. AND IF IT WAS UNDER WATER, and you all agree it was under water, then other considerations apply, not erosion. These other considerations have to do with how on earth one kind of sediment accumulated so slowly for so long under water, just that one kind of sediment just as presented in the walls of the Grand Canyon, and then after MILLIONS UPON MILLIONS OF YEARS, a different sediment started accumulating. Why not in hundreds of years? Decades? Why should there be any thick layers of identifiable sediments at all? Why not a conglomeration? Why not an inch of one followed by an inch of another for the whole column? Why ten feet of one and then fifteen feet of another? Each accumulated over millions of years -- if underwater, without erosion too, so that what you see is what you get. You really are NOT thinking about the actual situation I'm trying to get hold of here. Just about nothing but sandstone for millions of years? Just about nothing but limestone for millions of years? Come ON!

I'm going to have to break off at this point and resume answering this post later.


This message is a reply to:
 Message 29 by Jazzns, posted 03-17-2005 1:11 PM Jazzns has not replied

  
Faith 
Suspended Member (Idle past 758 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 94 of 127 (196285)
04-02-2005 8:03 PM
Reply to: Message 29 by Jazzns
03-17-2005 1:11 PM


Re: Hopefully Helpful Info About Sedimentation
* * * * *
Here's a creationist website saying what I've been trying to say so repetitively here (and to some so irritatingly) all along about why you can't extrapolate from present processes to the geo column, but they say it better:

...There seem to be no processes taking place in the present that are competent to explain the corresponding formations of the past. For example, the evaporative processes which are producing salt deposits today are leaving salt beds which are both qualitatively different and quantitatively trivial in comparison to the great thicknesses of pure salt and gypsum found in the geological strata. The same is true of coral and limestone formations. Great continent-wide formations of sandstone and shale are quite incommensurate with any beds of sand and silt being deposited by modern rivers. Modern volcanoes are in no way competent to produce the great thicknesses and region-wide areas of volcanic rocks found in the earth’s crust. Modern rivers could never produce the deep canyons or the thick beds of alluvium through which they flow. Modern glaciers could never produce the continental glacial deposits of the past. The present is not the key to the past. Catastrophism, not uniformitarianism, is the only sufficient explanation for the geologic column. ICR on sedimentation processes

* * * * *

quote:
Limestone is a neat geologic feature. YECs usually dodge my questions about limestone because it is very hard to fit limestone formation in a young earth and espeically a flood. Limestone is created from the fossils of dead sea creatures. A little sea creature will die and its body will fall to the bottom of the ocean just like a particle of silicate does for "regular" sedimentation. In order for limestone to accumulate in any thickness it requires a relativly calm warm environment like the bottom of the ocean or a lake. Near the shore where the tides are always mixing things up, limestone does not form so it it hard to imagine how a trillion trillion of dead sea creatures decided to settle out together during a worldwide flood.

The flood covered the land to some depth. Why wouldn't it have carried trillions of trillions of sea creatures over the land areas? They would all have died in the thick sediments stirred up by the rains and the flooding. How many, who knows, but very possibly many more than live in the sea at one time now. But also limestone isn't always organically formed. Some creationists claim the majority observed isn't organic.

However hard it is to make everything fit a worldwide Flood, it seems to me a lot harder to make it fit the Geo timescale, much harder to explain how you get 10 or 20 feet of limestone deposited extremely slowly over millions of years, followed by 10 or 20 feet of sandstone deposited extremely slowly over millions of years, followed by a few feet of clay/shale deposited at the same rate and so on for dozens of layers at least, and hundreds according to some reckonings.

What happened to the sea creatures while the sandstone and shale were depositing? What explains only sand for millions of years? Only clay? Only sea creatures?

quote:
Since the environment that allows limestone to form must be calm it is easy to see why we would expect limestone formations in particular to be pretty neat and flat. The bottom of the ocean and the bottom of lakes are pretty flat so there is no mystery there. Limestone does not form on land at all so if you were thinking that then I hope this clears that up.

No, it needs moisture of some kind, but inorganic limestone forms in damp caves in the form of stalagmites and stalactites, and it forms pretty fast too:

Pictures showing recent formation of limestone

quote:
Some limestone is also due to reef systems, (also a problem for how a 1000ft reef of delicate sea creatures could form during a flood).

These like reefs today are large habitats for little sea cretures and like most all limestone are packed full of marine fossils.


Presumably the corals would have been moved from one place to another in a flood. Here's what is said about corals on the same page on sedimentation from ICR that I quoted above:

During the upheavals of the Flood, extensive coral deposits in the warm antediluvian oceans were torn up, transported, and redeposited later around great rock mounds, giving a superficial appearance of having grown there in place, rather than having been washed into place. ICR on sedimentation processes etc.

If the idea is that the Grand Canyon formed in water, that helps deal with the questions about erosion to a great extent anyway as presumably the sediment just falls to the bottom and stays there. But even in that case FIFTY MILLION YEARS? Again, these strata are different from each other, made up of different hardened sediments, a limestone here, a different limestone on top of it, a shale, etc etc. Are you guys REALLY thinking about FIFTY MILLION YEARS when you are trying to explain to me how Oh well a bunch of stuff WAS on top of it but it got eroded away?

quote:
We can tell very easily when something was eroded away. It leaves behind what is called and erosional disconformity. Basically when you look at the rocks in detail you can tell that there was an abrupt break in the deposition only to be resumed by some drastically different sediment. Sometimes the deposition will even be at a different angle which means that the feature was tilted before sedimentation resumed. Sometimes there is not an abrupt change between the layers because all that happend was that the environment changed. If sandstone is being deposited near the shore and sea level rises then it will probably start to deposit silt instead without there ever being a break. All that happens is that the sand stops being buried by more sand and starts being buried by silt.

Yes, but you have to postulate a VERY rapid change, rise in sea level or whatever, as the strata clearly show sharp demarcations and not long periods of confusion of sediments. The abrupt breaks are what make the whole geo timescale questionable. They retain their flatness so where's the erosion you say the abruptness suggests? Quite the opposite is suggested -- NO erosion because that would destroy the flatness. I know there are pockets of different kinds of sediments in some layers but this is not what would be expected as the result of erosion of the layer over huge spans of years, but obliteration of the horizontal flatness/shape of the layer.

Not sure the tilting would have to have occurred before the sedimentation resumed. It could have happened in one tectonic catastrophe. For instance, looking at the bottom of the Grand Canyon it seems to me that the idea that the tilted strata would have been so neatly and horizontally sheared off over a few million years of erosion and then covered with neat horizontal layers over more millions of years doesn't fit any universe I've ever heard of. Seems more likely to me that something disturbed the lower part of the whole stack, that that part was tilted while still somewhat damp though highly compressed, and either the upper stack slid over it a ways or the lower stack was pushed under (big magma bubble suggested in the Grand Canyon area cross section would certainly have displaced and moved around the strata above it, and seems to have pushed the lower strata off to the side), and the weight of the upper sheared off the tilted stack, which was still damp and shearable. I don't know what happened either and my scenario may be silly as usual, but no sillier than the timetable idea of slow erosion to neat sheer horizontality of rock-hard layers diagonally thrust upward.

quote:
How we know something "WAs on top of it" is by diagnostic means. It requires a very detailed look at the rocks that you just won't get from looking at a big picture of the GC.

The idea that you have to look at the rocks microscopically to ascertain events that took millions of years makes no sense. Whatever took millions of years is GOING TO BE OBVIOUS on the face of it. If it's erosion, it's not going to leave a neat horizontal configuration of one kind of sediment.

Were these layers formed under water or not? You have to make up your mind.
quote:
Some were formed on land and some were not. That is part of how we know it took a long time to deposit the layers of the GC. Sea level rose and fell often during many many years. Sometimes it fell enough to expose that area to the air and either eroded some of the layers or deposited more stuff like the Coconino sandstone. This happened more than once during the geologic history of the GC. We would actually expect this and it would be kind of strange to see hundreds of millions of years of NO evidence that sea level has changed. That would be better evidence of a flood. Unfortunatly we do not see that evidence.

Sea level didn't change in a flood that covered the entire earth? What can you be thinking? It rose over a period of forty days, it stayed over the land for some period, during which the stirred-up sediments and dead sea life would have precipitated out over the land, and then it receded, during which it would have affected the land being exposed by waves and tides which might have further deposited sediments and sea life on land.

Yes of course you have to postulate many risings and fallings of the sea to account for what appears in the strata on the timeframe idea. But the idea that erosion during the exposed periods accounts for the sharp demarcations simply makes no sense. Erosion would have messed up the horizontality. I know I keep saying this but it's true, it's obvious, it would have. Where you find this erosion is in the abrupt change from one stratum to another, but that's no evidence of erosion at all. If it was out of water for part of those millions of years, how long -- half a million? 10 million out of the 20 a given layer is supposed to have taken to form? -- it would simply not exist as a layer at all. I know I keep saying this but it's OBVIOUS. Erosion would NOT leave a neat horizontal surface upon which a new sediment would gradually start depositing horizontally after the sea level rose again. And how long did it take while the sea level was rising anyway? If it crept up by the slow increments everything has to happen by in this jerryrigged timeframe scenario of millions of years, then why wouldn't the sea itself obliterate the layer with its waves and tides washing over it during the creeping up period?

quote:
So to make up our mind the answer is yes. Sometimes the deposition of the layers of the GC happened on land and sometimes it happend on water. Sometimes the layers were eroded and we see an erosional disconformity. Either way we know that sometimes the area was under water and sometimes it was not.

Let me be sure I'm understanding although I answered this above: You are saying that the evidence of erosion is the sharp demarcations between the strata?

If you're talking about erosion apparently you aren't talking about an underwater environment where you all seem to be saying that sediments settle to the bottom and stay put, and harden as the bottom drops or something along those lines. If it got eroded it must have NOT been under water. But then you all agree the canyon layers were formed under water. This does get hard to follow.

quote:
I can see how it is hard to follow if you have not been exposed to the concept before. Ocean levels rise and fall so sometimes land will be covered by water and other times it may not be. This is the case for the GC and why we see limestone which is very much a marine feature covered by the Coconino sandstone which is very much a desert feature.

Which is why you need all these postulated risings and fallings. Actually I have heard this scenario before. It boggled me then, it boggles me now. I see how it was arrived at but it doesn't make sense. And if the idea really is that the sharp demarcations are to be explained by erosion during periods above water that makes even less sense.

The Geo Column idea assumes that each layer is a "landscape" taht endured for a very long period of time. I keep coming to the Mississippian period because it seems simplest: Only one kind of sediment, redwall limestone, and the period is said to have lasted some 50 million years. ONLY redwall limestone made up that
"environment," that "landscape" for fifty million years?

quote:
As was mentioned in another post. The one layer of limestone is actually very complex. It would be very strange maybe to see 50 million years worth of sediment without some kind of dynamics. Luckily, we do see these dynamics and the redwall limestone is a good example of this.

The point is that the overall content is an enormously thick layer of at least 99% redwall limestone throughout the Grand Canyon area, as shown by both diagrams of the cross section that I've seen, into Utah to the north and no doubt east for some distance too, and what "dynamics" are going to change that fact?

How long was it in the sedimentary form?

quote:
I am not sure what this question is asking. I assume you are asking how long was it unlithified sediment? Well lithification does not happen all at once. As something gets buried it is subject to pressure and heat. The more it gets buried the more it gets compacted until it finally becomes stone.

Here's the picture. Let's assume sedimentation OUT of water. We are postulating back in time from what we actually see in the strata. We have a finished layer of stone, say sandstone, that is assumed to have taken, oh, what, 50 million years to form. It's forming on top of say a layer of, oh, shale, that has supposedly already formed and hardened (by my reasoning it couldn't have but let's pretend). It's got fifty million years to lay down 50 feet of sandstone and it is doing this by depositing grains of sand bit by bit, following the timeframe idea of slow deposition, centimeter by centimeter. How many years would it take for it to accumulate to a sufficient depth for the lower layers to begin to lithify?

Or were our dunes blown in all at once somehow?

quote:
There are even varying degress of this when talking about sedimentary rocks. You can find sandstone that is very loose and where you can still see the individual grains of sand very well. Then you can find different sandstone that is extremely hard and still harder to see the individual featuers of the sediment. For limestone, you can range from these very messy chunks of shells and material to very fine compressed rocks that do not even look like limestone until you pour some acid on it and watch it fizz. Basically, sediment stays sediment until it gets buried enough to compress it into rock. So a few layers down from the surface something might still be just loose sediment.

Yes, these are all processes that do not take great periods of time to occur. The question about the time a given layer remains unlithified sediment during the millions of years posited for its formation has to do with how much time it had to be disturbed by external processes such as weathering.

Was this underwater? Did it lithify during those 50 million years before the next layer / era began?

quote:
The bottom part of the layer probably started to lithify as soon as it was buried enough.

What's enough? This is SLOW formation remember. It's going to take MILLIONS of years to become 50 feet of rock.

quote:
The other important thing to think about is that the layers is MUCH thinner than it was when it was loose sediment. As things get buried they get compacted sometimes very drastically. A layer that is dozens of feet now may have been many hundreds of feet when it was still being deposited.

Good point. Thanks for reminding me of that. So our sand has to pile up to many hundreds of feet over the millions of years before it settles down into 50 feet of rock. All sand, nothing but sand, millions of years.

Oh, and over what extent of planet earth did this Mississippian era stretch, and is that "era" all characterized by limestone everywhere on earth?

quote:
The Mississippian was a time and no limestone was not being deposited everywhere during the Mississippian. There is Mississippian sandstone, igneous rocks, etc depending on what was being deposited where. There are also places where the geologic history is missing any Mississippian rocks at all. These either represent areas where the erosion was geater than sedimentation during the Mississippian or where the Mississippian rocks have been eroded since that time.

...A single layer of global limestone would mean that the whole world was under water. This would be great evidence for some kind of global flooding if anyone could find such a layers that was global. No one has so far.


That's all clarifying, thanks. As I understood it, the way the time periods are established is by the fossil contents of the layers. So the same fossils are found in different sediments in different parts of the world?

Great swaths of the whole earth covered in sedimentary limestone for how long?

quote:
Nowhere has anyone found a global layer of anything except maybe the K-T Boundary which is a very thin layer of iridium probably from a stellar impact.

I didn't say "global," Jazz, I said "great swaths." But perhaps it's only in isolated areas such as the greater Grand Canyon area? Certainly a huge swath of limestone was laid down there.

Sorry if this is all rather disjointed. I'll try to boil it all down at some point, but right now I just want to get through your posts.


This message is a reply to:
 Message 29 by Jazzns, posted 03-17-2005 1:11 PM Jazzns has not replied

  
Faith 
Suspended Member (Idle past 758 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 95 of 127 (196330)
04-03-2005 1:05 AM
Reply to: Message 80 by Jazzns
03-23-2005 9:33 PM


Erosion between layers & unconformities
A partial answer to your #80. In preparation I did a couple of sketches of my own of what it seems to me the Grand Canyon walls should *really* look like given the assumption of millions of years of formation of each layer. Basically it's the same diagram but I elaborated the second a little more in the direction I have in mind, showing what I think actual erosion would do to the individual layers as they were forming -- no more nice neat horizontality. I used the MS Paint program and I made them into JPG files, but it turns out Image Shack won't accept them, says the files are corrupted -- I forget the exact message but something along those lines. I'm afraid they're also too large and I haven't learned the HTML way to post here. Well, maybe I'll try pictures again eventually.

Meanwhile about the dis/non/unconformity information, I've understood the basic concept all along but the terms are a bit hard to keep in mind. Nonconformity = contact between sedimentary rock and other kinds of rocks, check; Angular unconformity = contact of layers at an angle to layers at another angle, say horizontal, check. But it is mainly the DISconformity that is of relevance to this discussion, as that is the term for the supposed erosion between layers.

quote:
Knowing this much tells us that whatever it is that created the GC was more complicated than just dumping a lot of dirt.

Um,not sure how you might have gotten the impression I thought such a thing, but onward...

quote:
In fact, if the creation of the GC was due to a single depositional event we should not expect to see any unconformities at all.

But I don't have any problem at all expecting to see them! Tectonic activity caused by the Flood would explain the angular unconformities for instance as it displaced layers laid down in the Flood. Irregularities in the deposition of a particular layer wouldn't be at all unexpected with sediments that were laid down by water, including drainage between layers moving some sediments and causing some apparent erosion on a small scale.

quote:
The fact that these unconformities exist attests directly to multiple depositional events. Faith, if you are going to contest the mainstream interpretation of the formation of the GC, this is a good place to start laying some common ground from which to diverge. Do you agree that the fact of the existence of unconformities, without necessarily any admission of time, shows that with very little uncertainty that multiple depositional events are responsible for the formation of the GC?

Not sure why you emphasize the unconformities, as the layers themselves are clearly separate depositional events from each other.

quote:
And they were eroded away PERFECTLY...'

Eroded away "perfectly" is not a very accurate statement. The diagnosis of a disconformity comes from that fact that the contact between the two layers is explicitly not uniform over an area. There very existence of an "imperfect" contact is what tells us that erosion has happened. The fact that it is still parallel just means that the area was not tectonicly active over the period between the erosional event and the subsequent depositional event that caused the disconformity...


Everything you say suggests minuscule imperfections, but given the millions of years no way would the imperfections be minuscule if we're talking about erosion over at least much of that time, even to the removal of entire layers you expect should be present. Here's where I wish I could show you my sketches. Even they show far more regularity than I think would actually exist given the millions of years.

quote:
In other words, flat places are still flat.

No way, not after a million years of erosion.

quote:
Given that, if there was an interruption in deposition for some reason such as sea level falling, then when deposition resumed there is no reason to expect that it would not continue to lay new "horizontal" layers over slightly eroded "horizontal" layers.

Except that the eroded layer would not be merely "slightly" eroded after a long long long period exposed to erosion.

quote:
This is in stark contrast to the west coast of the North America which is extremely active where layers are being bent, tilted, folded, etc due to tectonics. In this case we would expect there to form many angular unconformities.

But angular unconformities aren't really relevant here. Obviously tectonic activity has acted as you say on already formed layers, but I'm talking about the formation period of each layer and how erosion and other weather effects would have obliterated its horizontality over even as "little" as a million years.

quote:
Then when we find angular unconformities we know to look for other examples of tectonic activity in the geologic history of the area. In the case of the angular disconformity of the GC, this is exactly what we find. After the angular (originally horizontal) layers of the GC were laid down there was tectonic mountain building activity that caused those layers to be tilted. This evidence correlates the reason and timing for what we see with regards to angular layers in the GC.

With regards to this. Do you agree that the way we know an unconformity exists is due to the "imperfect" nature of the contact between the layers?


1) The definition at Wikipedia didn't mention any visible clues in the layers, just said "An unconformity is a gap in time in rock layers, where erosion occurs while deposition slows or stops. ...In an unconformity, data is lost, and geologist must use other clues...

2) This "imperfect" nature of the contact is still in question. I see the illustration on the model of the Grand Canyon you linked, of disconformities at the surface of two layers, obviously something that occurred BETWEEN the layers, implying it happened AFTER the layer was formed, only on the SURFACE of it. But according to the Geologic Timescale it took millions of years to form those layers, so why is the erosion only on the surface, AFTER they were formed, but there is no erosion shown DURING that long period? I'd guess that these disconformities occurred between the layers after they were formed -- maybe after the one layer was laid down but the upper layer was not yet in place, or after the upper layer was in place, and in fact many layers above, as water would have continued to be pressed out between the newly formed layers for some time afterward and displaced some sediments in the process.

See, the more you tell me, the more I know, the more convinced I am that my original impression is correct.


This message is a reply to:
 Message 80 by Jazzns, posted 03-23-2005 9:33 PM Jazzns has replied

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 Message 97 by Admin, posted 04-04-2005 1:50 PM Faith has replied
 Message 98 by Jazzns, posted 04-05-2005 1:07 PM Faith has replied

  
Admin
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Message 96 of 127 (196377)
04-03-2005 9:51 AM
Reply to: Message 95 by Faith
04-03-2005 1:05 AM


Re: Erosion between layers & unconformities
Faith writes:

I used the MS Paint program and I made them into JPG files, but it turns out Image Shack won't accept them, says the files are corrupted -- I forget the exact message but something along those lines. I'm afraid they're also too large and I haven't learned the HTML way to post here. Well, maybe I'll try pictures again eventually.

Please email any images to Admin's Email and I'll make them available at EvC Forum so you can include them in your messages.


--Percy
EvC Forum Director

This message is a reply to:
 Message 95 by Faith, posted 04-03-2005 1:05 AM Faith has not replied

  
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Director
Posts: 12814
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Message 97 of 127 (196677)
04-04-2005 1:50 PM
Reply to: Message 95 by Faith
04-03-2005 1:05 AM


Re: Erosion between layers & unconformities
Here's a thumb of the image, you should be able to fetch the path off it by right clicking on Properties so you can use it in your own messages, let me know if you need help (don't worry, it looks great at full size:


Click to enlarge

PS - If you're any good at graphic design, I need a new site logo.


--Percy
EvC Forum Director

This message is a reply to:
 Message 95 by Faith, posted 04-03-2005 1:05 AM Faith has replied

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Jazzns
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Posts: 2657
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Joined: 07-23-2004


Message 98 of 127 (196947)
04-05-2005 1:07 PM
Reply to: Message 95 by Faith
04-03-2005 1:05 AM


Re: Erosion between layers & unconformities
I combined your two responses into one. Here we go!

There are two major components from the initial part of your rebuttal from the following:

Most of these normal events have been known to alter the topography of the land. It is within historical time that such events may appear insignificant, not over millions of years, and insignificant to us because they don't happen everywhere at once, we are used to them and have learned to deal with them more or less, at least in some parts of the world. But they would not be dwarfed at all by millions of years, as you claim, but on the contrary, multiplied to enormous effects. Every year the world experiences a round of them and we manage to recover one way or another, even with great loss of life in some cases, but recover nevertheless, and sometimes we note that the terrain has changed, but we pick up and go on. Just multiply these yearly effects by millions.
...
Yes, but again these processes cannot be expected to build up regular horizontal layers of the sort we see in the strata. They shift things around, they do not allow neat layers to form.

The first component of your statement is the mixing up of surface layers of sediment by events such as a hurricane. When explained that the only thing needed is deposition to be greater than erosion you continued with the argument that you don't expect the layers to be horizontal.

The whole point of this surface weathering argument from my perspective boils down to this incredulity about horizontal layers forming at the surface.

Let’s use a concrete example like the Coconino Sandstone. From http://www.geocities.com/earthhistory/grandb.htm :

Unlike obviously marine formations, which tend to thicken towards the west (seaward), the CS thins toward the west, and is thickest (about 1000ft) in the central Grand Canyon area. Further, the orientation of dunes and wind-ripple marks within the CS suggest that the Coconino erg was transported by wind from the north, not by water from the west.

Really thick in one place and thin in another? Well, doesn't that mean that it has to slope? Doesn't that break the law of original horizontality?

The answers are yes, yes, and no respectively. The whole point about original horizontality is that in a given spot a deposit will be horizontal with respect to the layers above and below it. If it is not horizontal with respect to itself 200 miles away then that is okay. When we look at the GC, which is a cross section of the formation in one spot compared to the breadth of it across the area, it looks very nice in between the layers near it. In a different location it might not even be between the same layers, at the same depth, of the same thickness, etc.

Now let’s try to figure out what would happen to a desert full of sand dunes as it experiences the occasional El Nino. Sand at the very top will get wet and be blown around. Some new sand will be deposited by the extra weathering going on. Some sand that is already there will get blown away. When normal deposition resumes, the normal rates of deposition will determine if the sand that is now at the surface will continue to be buried or continue to be eroded depending on what is happening as a net average to that environment.

Part of the problem is that I think you are forgetting that, most of the time, land based deposits are continually eroded. So yes, we do expect things like a hurricane or something to destroy something faster than it was already being destroyed if that was its erosional fate anyway. Most stuff on land gets eroded and ends up in the ocean or a lake. We do expect though that the minority of places like river valleys, basins, etc to be able to accumulate sediment and things like a hurricane are going to be more likely to help put stuff there rather than take stuff away. So some places on land will be able to accumulate and preserve their deposits, especially if they then become inundated with water which is REALLY good at preserving deposits.

The GC is part of a rare formation where this was the case. A land deposit was part of a net depositional environment where more stuff was being added than taken away. Then the sea came back and it was preserved by the continued deposition of marine sediments. Other land based sand deposits might build up to the point that they are now the high ground and then switch to an environment where it is the source rather than the end of a depositional system. Some get preserved, some do not. The Coconino just happened to be one of the ones that did.

I'm not getting this picture. You aren't describing these layers, their contents, their thicknesses, comparing them to the Geo Column. You have to show that the rate of deposition and the distinctions between layers could explain the buildup of the Geo Column over millions of years. And who said anything about these layers being "from a different source other than the delta" anyway?
...
Sure, but many layers building up in a delta in historical time doesn't exactly commute to layers built up over millions of years as seen in the Geo Column. The best you can extrapolate is that water deposition is likely the cause.

I only assumed you would not agree that the whole delta was created by the river itself. If it had been then we are looking at an old earth scenario because, not only is it 7 miles thick in some places, it has migrated from Illinois over time as indicated by the sediments and their migration over the landscape. I can only assume that there is some other YEC explanation of why there are deltaic sediments in the middle of the geologic column in Illinois which are then covered up by different sediments, all supposedly from the flood.

Source: www.talkorigins.org/indexcc/CD/CD211.html

We can also tell a lot more about the sediments then just that they were deposited under water. Delta sediments have very specific characteristics.

From:http://gpc.edu/~pgore/geology/historical_lab/sedenvirons.htm

1. Deltas are fan-shaped deposits formed where a river flows into a standing body of water, such as a lake or sea. Coarser sediment (sand) tends to be deposited near the mouth of the river; finer sediment is carried seaward and deposited in deeper water. Some well known deltas include the Mississippi River delta and the Nile River delta.

So what happens then when we find a fan shaped pile of sediments with a gradient of particle sizes starting at coarse near the center to fine near the edges in the middle of the geo column for a particular area? What is the better explanation, that it was once a delta or that the flood just made it look like a delta.....somehow?

And since you are clear that the deposition is of sediments brought down from eroded upstream rocks and terrain, how does the idea of "landscapes" ever come up with regard to any of the strata as explained by water deposition anyway?

Just to be precise, let’s use the terminology of "depositional environment" instead of "landscapes". The site that I listed above talking about deltas has a nice list of depositional environments and their descriptions. An ocean and a desert are both depositional environments.

In any case, as I recall, it look quite a while before anyone even said that the Grand Canyon was formed in the ocean, and some appeared to be unsure about how much of it was formed that way. If any strata lower in the column appear to be eroded, that also remains to be explained in terms of ocean deposition.

Why don't we do a summary of the deposition of the GC as it is postulated by classical geology. This should explain when and why things were eroded.

Distilled from

http://www.kaibab.org/geology/gc_geol.htm#where
and
http://www.kaibab.org/geology/gc_layer.htm#vs


  1. 1.25 GA to 825 MA years ago the bottom most layers were laid down. These are coastal layers indicating shallow marine or beach environments.

  2. Between 825 MA 550 MA more layers were deposited but these were also eroded in that time indicating that the ocean regressed. The area was tilted during that time.

  3. Between 550 MA and 540 MA the ocean began to transgress and the area was a coastline with shallow ocean sediments. The only reason I wanted to point this out specifically is that within the structure of this layer there is evidence of islands! So much for neat and horizontal over a large area.

  4. Between 550 MA and 300 MA an ocean transgressed and then regressed leaving deep ocean layers behind.

  5. Between 300 MA and 280 MA the area was a coastline and shallow marine sediments indicating the end of the regression.

  6. Between 280 MA and 270 MA the ocean had regressed to the point that the environment was total sub-aerial. This is when the Coconino sandstone was laid.

  7. Between 270 MA and 250 MA the ocean started to transgress onto land again leaving shallow marine sediments.

  8. If any more layers had been deposited on top of that they have been eroded since the uplift of the Colorado plateau

Notice, if erosion keeps on going like it is now, eventually the Coconino sandstone will be gone and you will have a situation of missing layers like there is in the middle of the column of the GC. If the ocean stays gone long enough then all that geologic history gets erased.

It appears to me that ALL the horizontal -- or previously horizontal and still parallel -- strata wherever they are found MUST have been formed in water, but so far nobody has confirmed that.

The Coconino sandstone is most definitely not a marine formation. The cross-bedding plus the characteristics of the sand particles plus the terrestrial fossils all account to that. Also, the very first link in this post gives a good treatment of why the Coconino is most certainly a land deposit. Other deposits in the GC indicate a shoreline with partial marine and partial sub-aerial sediment. The rest are totally marine.

Such processes would certainly obliterate a layer of sediment over millions of years (if not underwater).

Well, I don't know how mudslides would obliterate the layers they cover. It seems to me that they would help preserver the layers that get covered by them.

Other events certain would weather things quicker but where does all the weathered material go? It goes to low places like basins, valleys, lakes, oceans. Tornadoes and hurricanes help not hurt the process of weathering and sedimentation. If you respond to this with more disbelief about the layers not being horizontal then I really think you need to give yourself the time to understand what is really meant by the law of original horizontality. What you claim is real and what is actually real are two different things with regards to this. I mean no offense by this. I am just trying to warn you that you are treading on territory where it simply looks like you are uneducated about the topic. If you continue with the same reasoning after it has been explained to you it will only seem that you are willfully uneducated about the topic. If you sill just don't understand what I mean by "horizontal with respect to" then ask me to clarify.

All I'm going to say to the entire quotation exchange above is that you are not addressing the effect I'm saying all these processes would have on the strata DURING THEIR MILLIONS OF YEARS OF FORMATION, when the sediments were still presumably quite moveable. You keep imagining things happening AFTERWARD, piling on top of the formation and so on, but remember, the formation itself was presumably, based on the timetable idea, in the process of forming for millions of years and presumably, therefore, subject to all these normal processes over those millions of years. You say there are records of mudslides. Fine. But surely a mudslide would have destroyed any layer in the process of forming before it slid -- not something piling on TOP of it, but the layer itself sliding. And if a mudslide occurred on top of a layer not yet formed then it would have interrupted it anyway. And how many of these do you suppose would have happened in millions of years here and there? Combined with all the other kinds of disturbances I can't see any strata forming at all.

Mudslides usually happen to things that are being eroded so I wouldn't expect the content of the mudslide to be that of something that was currently undergoing deposition. Now if it slides on top of something else like a bunch of trees then the forest floor and those trees might be preserved as long as erosion doesn’t strip away that too. This is how things like the Joggins polystrate trees were formed and the paleosols they are planted in. Bill Birkland has a great post on this forum somewhere that shows a polystrate telephone pole and some polystrate houses. Good example about how some things can be preserved by localized catastrophe.

Mudslides are not how most things get preserved but the whole point of the example was to show that localized catastrophe mostly serves to bury things more rather than unbury them. I have said it before but I will repeat for effect. Tornadoes and hurricanes and such all send sediment into low places just like we would expect. Even if they hit the low place directly all they are really doing is mixing up the topmost part of a very thick sediment. These things help deposition not hurt.

Yes, as you say, "SEDIMENT ON THE SURFACE IS SUBJECT TO WEATHERING." Thank you. Now extrapolate that TO MILLIONS OF YEARS OF extremely slow buildup on that surface which weathering would affect to a depth greater than the deposition depth implied by those millions of years and try to figure out how a layer stayed a layer for even a tenth of that time.

All surfaces are subject to weathering, not all are subject to being weathered away. I repeat that most land surfaces are eroded but some are not. Those some may end up becoming part of the geologic column if they are further preserved. The Coconino sandstone was one of the some.

UNLESS IT WAS UNDER WATER. AND IF IT WAS UNDER WATER, and you all agree it was under water, then other considerations apply, not erosion.

Not everything that is deposited under water gets preserved and everything that gets preserved is not necessarily under water. Most stuff that is deposited under water is preserved and most stuff that is not deposited under water is not preserved. It is not an all or nothing thing with regards to sediment preservation. You need specific conditions to preserve a layer of sediment. Those conditions are well met for most marine environments and are well met in a few land environments.

These other considerations have to do with how on earth one kind of sediment accumulated so slowly for so long under water, just that one kind of sediment just as presented in the walls of the Grand Canyon, and then after MILLIONS UPON MILLIONS OF YEARS, a different sediment started accumulating.

We don't expect things to change much very quickly so why should different sediment be deposited? Why wouldn't an ocean still be an ocean over a couple dozen million years? If it is still an ocean then why would we not expect the layers of sediment that it is dropping to be deep marine sediment with slight fluctuating variations as sea level changed slightly like in the case of the redwall limestone.

Why not in hundreds of years? Decades? Why should there be any thick layers of identifiable sediments at all? Why not a conglomeration? Why not an inch of one followed by an inch of another for the whole column? Why ten feet of one and then fifteen feet of another? Each accumulated over millions of years -- if underwater, without erosion too, so that what you see is what you get. You really are NOT thinking about the actual situation I'm trying to get hold of here. Just about nothing but sandstone for millions of years? Just about nothing but limestone for millions of years? Come ON!

What is funny is that a lot of the things that you just listed as if they should be seen are actually seen. While trying to destroy the foundation of classical geology you are actually defining parts of it.

Sometimes a deposit does represent only a few hundred thousand years, or a few thousand years, or a few hundred years, or a year, or even a few days.

Sometimes deposits are a conglomeration! There is actually a rock type called that! A conglomerate rock is one that is composed of a bunch of different sized grains ranging from a stone to a fine grain of sand. These are usually found in river, glacier, and alluvial fan deposits. For things that are not conglomerates we have known mechanisms for why they get sorted; namely that we are watching them being sorted naturally today.

The way classical geology explains these changes are by changes in the environment that collects the sediment. I offer to you as a counter the same question, why would a flood create layers of identifiable sediment? What process sorted the sediment and why did it reverse that sorting numerous times during the life of the flood?

Deposits can range from miles to thousands to hundreds of feet thick all the way to as small as inches and even millimeters! Yes in some places we actually do see an inch followed by another inch etc!

With regards to the paragraph you quoted.

...There seem to be no processes taking place in the present that are competent to explain the corresponding formations of the past. For example, the evaporative processes which are producing salt deposits today are leaving salt beds which are both qualitatively different and quantitatively trivial in comparison to the great thicknesses of pure salt and gypsum found in the geological strata.

This is blatantly false. Older evaporite deposits contain pollen, other plant life, other playa lake features, and even other sediments. The notion of evaporite deposit purity give by YECs is directly false. They are either lying or just don't know what they are talking about. Here is proof:

From www.iidb.org/vbb/archive/index.php/t-38096.html

This claim can be traced back to Sozansky (1973), who claimed that the (alleged) absence of pollen and/or planktonic tests in evaporite deposits argues against an evaporation model. However, it is now known, and has been known for decades, that many evaporite deposits do in fact contain "impurities" such as pollen, plankton, algae, fungi spores, volcanic ash layers, and so forth, which we would expect on the restricted-marine, basin-evaporation theory, but not what we would expect if these salts were somehow rapidly extruded underwater in a global flood.

For instance, the 2km+ thick Sedom Formation evaporites in the Dead Sea Basin are about 80% pure halite, with 20% gypsum, marl, chalk, dolomite and shale (Niemi et al., The Dead Sea: The Lake and its Setting, Oxford Monographs on Geology and Geophysics No. 36, p. 46). Significant amounts of pollen are also present in these evaporites as well. See also: Ulrich Jux, The Palynologic Age of Diapiric and Bedded Salt, Department of Conservation, Louisiana Geological
Survey, Geological Bulletin 38, October, 1961; Wilhelm Klaus, Utilization of Spores in Evaporite Studies, in Jon L. Rau and Louis F. Dellwig, editors, Third Symposium on Salt, Cleveland: The Northern Ohio Geological Society, Inc., 1970.

The Paradox Basin evaporites, mentioned earlier, in fact have many thin interbedded shale layers containing brachiopods, condonts, and plant remains (Duff et al., Cyclic Sedimentation, Developments in Sedimentology, no. 10: Elsevier Publishing, 1967, p. 204).

My favorite part is that there is actually dolomite and shale in the middle of an evaporite deposit. Evaporite purity is a pure misnomer. RandyB refused to engage me when I presented this to him. Evaporites are extremely hard to make comply with a young earth. So hard that no YEC yet has posed an even slightly plausible explanation for why these things would form in the middle of a flood.

The same is true of coral and limestone formations. Great continent-wide formations of sandstone and shale are quite incommensurate with any beds of sand and silt being deposited by modern rivers.

No one says that continent wide formations are formed by rivers and most certainly coral and limestone is not formed by rivers. These are formed along with sandstones and shales in oceans where there is plenty of room to make continent wide formations given that there is more ocean bottom then continent.

Modern volcanoes are in no way competent to produce the great thicknesses and region-wide areas of volcanic rocks found in the earth’s crust.

Not all igneous rock is volcanic.

www.encyclopedia.com/html/b1/batholit.asp

If they truly mean just volcanic rock then they might not be considering that much more volcanic activity is known to have occurred in the past. How again does a flood create volcanoes? Why would it create more in a year than geologic time proposes? What happens to all that heat? If it all formed under water, why isn't all of the volcanic rock pillowed?

www.state.me.us/doc/nrimc/mgs/sites-2003/jan03.htm

Modern rivers could never produce the deep canyons or the thick beds of alluvium through which they flow.

Why would they not especially if the beds of alluvium are the exact same that get deposited every time that river floods? Why would a flood happen to drop thick beds of alluvium right where a river would be making it look like the river did it?

Modern glaciers could never produce the continental glacial deposits of the past.

Modern glaciers are nothing like the glaciers of the past. Of course modern glaciers are insufficient to account for all the glacial deposits ever found. During an ice age though and the multiple ice ages that occurred in the past, those mammoth glaciers certainly could account for it all.

Glaciers will often carve out deep and long gouges out of the underlying rock as it drags huge boulders in its flow. We see this today. What happens then when we see one of these big gouges in the middle of the geologic column? How did the flood make that gouge look exactly like a glacier did it? How did it do it to soft sediment? Why do we see these things in the middle of that Sahara Desert? How did glaciers get there or how did the flood mimic the fingerprint of glaciers there?

With regards to your further response:

The flood covered the land to some depth. Why wouldn't it have carried trillions of trillions of sea creatures over the land areas? They would all have died in the thick sediments stirred up by the rains and the flooding. How many, who knows, but very possibly many more than live in the sea at one time now. But also limestone isn't always organically formed. Some creationists claim the majority observed isn't organic.

Even if they could have been all alive at once, why did it sort them? The certain organic origin of limestone is covered in my previous post and in brief when you bring it up again below.

What happened to the sea creatures while the sandstone and shale were depositing? What explains only sand for millions of years? Only clay? Only sea creatures?

The ocean was either too shallow or too deep for life to live in great abundance. There is a zone a certain distance off shore that is ideal for limestone depositing creatures to live. Go farther and they can’t, go shallower and they can't. You are also being much to general when you talk about "only" sandstone or "only" limestone. You should be saying "mostly" limestone because even within limestone you can have sand and silt.

No, it needs moisture of some kind, but inorganic limestone forms in damp caves in the form of stalagmites and stalactites, and it forms pretty fast too

But those caves get the calcite FROM already existing limestone. See my previous post where you gave me those links. No YEC has a method of original formation of inorganic limestone that I have ever seen and some even just say it was all formed by creatures pre-flood which is totally implausible. In any case you have every different YEC organization with a slightly different and often conflicting version of where limestone comes from.

During the upheavals of the Flood, extensive coral deposits in the warm antediluvian oceans were torn up, transported, and redeposited later around great rock mounds, giving a superficial appearance of having grown there in place, rather than having been washed into place. ICR on sedimentation processes etc.

What is the more simple explanation?


  1. That a giant flood sorted out all these marine creatures and only these marine creatures and piled them up in growth positions to look exactly like the same coral reefs that we can go into the ocean and look at today.

  2. That it actually was a coral reef?

Yes, but you have to postulate a VERY rapid change, rise in sea level or whatever, as the strata clearly show sharp demarcations and not long periods of confusion of sediments. The abrupt breaks are what make the whole geo timescale questionable. They retain their flatness so where's the erosion you say the abruptness suggests? Quite the opposite is suggested -- NO erosion because that would destroy the flatness. I know there are pockets of different kinds of sediments in some layers but this is not what would be expected as the result of erosion of the layer over huge spans of years, but obliteration of the horizontal flatness/shape of the layer.

Why? Why would it have to be a rapid change especially when the deposits show a gradient of sediment as it changes from one to the other? Your sharp demarcation is only true from you macroscopic photograph of the layers of the GC. Take a look at them in detail and what you really see is a graded continuous deposition where the only thing that changed is the type of particle being deposited. If all we had was a look at the cross section of the GC from a distance then I might even be a YEC. It is a good thing that we can actually cut into the rock and see what is really going on over wide areas.

Not sure the tilting would have to have occurred before the sedimentation resumed. It could have happened in one tectonic catastrophe.

As I have said before this is an extremely hard thing to defend. The fact of the erosional contact between the tilted layers and the horizontal layers is the biggest thing I think along with why the top layers were not disturbed. No tectonics ever postulated by geology or any ambitious YEC could tilt the bottom layers w/o disturbing the top layers. Even if you had that you need to explain the erosion.

The idea that you have to look at the rocks microscopically to ascertain events that took millions of years makes no sense.

Why do you think that everything must be obvious at a macroscopic level? I wasn't even talking about putting rocks under a microscope, all I am saying is that you have to go down there, cut into the rock and look at the contact between the layers up close. You can't diagnose an unconformity from an aerial shot.

Whatever took millions of years is GOING TO BE OBVIOUS on the face of it.

No it is not. Rocks get compressed, that is what they do. Sometimes you need to actually go look at the specific parts of it in detail.

Yes of course you have to postulate many risings and fallings of the sea to account for what appears in the strata on the timeframe idea. But the idea that erosion during the exposed periods accounts for the sharp demarcations simply makes no sense.

Erosion does not account for the demarcation between all the layers. Certainly where you have a disconformity that is a sharp demarcation but the difference between the other layers is a change in the type of material being deposited. There is no break in the deposition in this case. No one ever said that erosion had to happen in between each and every layer.

Erosion would have messed up the horizontality. I know I keep saying this but it's true, it's obvious, it would have.

No it is not obvious. This is a bare assertion with no evidence. I would expect all sediment to be deposited horizontal with respect to the other layers since that is both what we see happening today and what we see evidenced in the geologic column both "recent" and "ancient" whatever you want that to mean.

Where you find this erosion is in the abrupt change from one stratum to another, but that's no evidence of erosion at all.

Incorrect, evidence of erosion is given by the discovery of a disconformity which has specific properties that make it a disconformity, not all changes in layers are due to a disconformity.

If it was out of water for part of those millions of years, how long -- half a million? 10 million out of the 20 a given layer is supposed to have taken to form? -- it would simply not exist as a layer at all. I know I keep saying this but it's OBVIOUS. Erosion would NOT leave a neat horizontal surface upon which a new sediment would gradually start depositing horizontally after the sea level rose again.

Depends on where you are talking about. Also, these things that you are saying are obvious are simply not obvious. I know this is frustrating to you but you have to understand that it is not obvious to me and it seems like it was not obvious to those who you were having this conversation with before. If I am being stupid then you have to dumb it down and explain it to me in simpler terms. Just saying that it is obvious is not going to lead us anywhere. There are a ton of things that I could say are obvious to me but most certainly would not be to you. I am specifically asking for detailed clarification for this.

What is obvious to me is that we see horizontal deposition going on today despite things like hurricanes, etc so why could it not have also happened this way in the past?

And how long did it take while the sea level was rising anyway? If it crept up by the slow increments everything has to happen by in this jerryrigged timeframe scenario of millions of years, then why wouldn't the sea itself obliterate the layer with its waves and tides washing over it during the creeping up period?

It might obliterate some of it and it might obliterate all of it. With the Coconino sandstone it didn't obliterate all of it. Why would it have to remove it all?

Let me be sure I'm understanding although I answered this above: You are saying that the evidence of erosion is the sharp demarcations between the strata?

No, I am saying it is due to a non-uniform and drastic contact between the layers. Just being a different layer does not automatically make you a disconformity. I have explained this also above so I won't get into it much more. If you are still confused about this then please ask and I will gladly clarify.

The point is that the overall content is an enormously thick layer of at least 99% redwall limestone throughout the Grand Canyon area, as shown by both diagrams of the cross section that I've seen, into Utah to the north and no doubt east for some distance too, and what "dynamics" are going to change that fact?

I am not sure how this question relates to the impurity of the limestone. I never questioned the breadth of the limestone. I was responding to you when you said that you couldn't believe that only limestone was being deposited. My point was that it was not just limestone just mostly limestone. Since you didn't respond to that point I don't really know what to say. The breadth was not in dispute. That whole area was an ocean so certainly the same type of deposits would accumulate. Certainly wherever the shoreline was during the time of the deposition of the redwall limestone, we should not expect to find the same type of deposits. Since I don't know what is "next to" the redwall limestone at its edges I cannot comment with specifics. I would expect it to be some kind of shallow marine sediments like sandstone or sandy limestone.

How many years would it take for it to accumulate to a sufficient depth for the lower layers to begin to lithify?

I am pretty sure that answer is a big unfulfilling, "it depends". It depends on the type of rock, the rate of sedimentation, if there are chemicals in water that are more helpful by "gluing" things together when they precipitate out of the water, if the deposition is on land or in water, what is being deposited on top of it and why, etc.

Or were our dunes blown in all at once somehow?

That would be silly. Sand probably started being deposited long before the environment became sub-aerial. Now with piles of sand the wind would get to blow it around while more sand was coming in from whatever sourced the original sand. No one is saying that sea level would drop in an instant and that wind would blow in these huge dunes. THAT would be something which is catastrophic.

Yes, these are all processes that do not take great periods of time to occur. The question about the time a given layer remains unlithified sediment during the millions of years posited for its formation has to do with how much time it had to be disturbed by external processes such as weathering.

Once it is buried it is not exposed to weathering anymore. Only the top most layers are weathered. And these will only be "weathered away" if the accumulation over time is less than the erosion over time. It can stay unlithified for as long as it needs to as long as it’s continuing to get buried. Also, if it was deposited in an environment that was likely to bury it in the first place, it is also likely to continue to bury it until lithification is certain.

Good point. Thanks for reminding me of that. So our sand has to pile up to many hundreds of feet over the millions of years before it settles down into 50 feet of rock. All sand, nothing but sand, millions of years.

No. Just mostly sand. A beach should stay a beach for a decently long time. And don't forget, terrestrial trace fossils. Those seem to continue to be ignored.

That's all clarifying, thanks. As I understood it, the way the time periods are established is by the fossil contents of the layers. So the same fossils are found in different sediments in different parts of the world?

The time periods are not established by the fossils. All fossils do is give a clue as to a ballpark of the time of the rock which may span multiple time frames. Other methods including relative positioning and radiometric dating must be used to pin it down to a specific spot in the geologic time scale.

But I don't have any problem at all expecting to see them! Tectonic activity caused by the Flood would explain the angular unconformities for instance as it displaced layers laid down in the Flood. Irregularities in the deposition of a particular layer wouldn't be at all unexpected with sediments that were laid down by water, including drainage between layers moving some sediments and causing some apparent erosion on a small scale.

Actually, knowing what I do about basic hydraulic sorting I would not expect anything that you just said. If all this stuff was laid down in a flood I would expect all the big grained stuff to be on the bottom and all the small grained stuff to be on the top. What flood geologists have to do is explain why this is true sometimes and then reversed and reversed again, etc. This explanation has not been given thus far by any of the "big" YEC organizations.

I would also not expect any erosional surfaces because there would be no time or mechanism for displacing sediment in a drastic net depositional event like the postulated flood. What flood geologists need to do is explain the mechanism for causing erosional unconformities under water and to show that this mechanism actually works within their flood model. Where is that unified flood model anyway? Maybe you could point us at it? It should be peer reviewed by all the leading YEC organizations, it should be widely agreed upon by them, explain all the facts, etc.

Not sure why you emphasize the unconformities, as the layers themselves are clearly separate depositional events from each other.

No they are not. Where there is no unconformity there is only a change in the type of deposition. Deposition is never stopped so it is not another depositional event. This is a very important point. In some places we have deposition being ceased, in some cases parts of the deposits are removed, and then deposition resumed. Only when this happens is a disconformity created. If a flood did this then it must be shown why, how, and how that explanation is better than the mainstream one.

Everything you say suggests minuscule imperfections

What gave you that idea?

but given the millions of years no way would the imperfections be minuscule if we're talking about erosion over at least much of that time, even to the removal of entire layers you expect should be present.

Who said the changes are minuscule? All I meant to say is that you are not going to see the disconformity just by looking an aerial shot of the GC. You actually have to drill or cut into the rock and look at it to see a sharp contact rather than a simple graded change in deposit. Geology isn't just staring at pictures and thinking up neat ideas. You won't get the evidence of the disconformities from a macro scale picture.

But angular unconformities aren't really relevant here. Obviously tectonic activity has acted as you say on already formed layers, but I'm talking about the formation period of each layer and how erosion and other weather effects would have obliterated its horizontality over even as "little" as a million years.

Angular unconformities are extremely important here. They are part of the history of sedimentation of the column of the GC and therefore they need to be explained. These things were laid down, tilted, eroded, and further buried by some process. Any flood model must explain this.

2) This "imperfect" nature of the contact is still in question. I see the illustration on the model of the Grand Canyon you linked, of disconformities at the surface of two layers, obviously something that occurred BETWEEN the layers, implying it happened AFTER the layer was formed, only on the SURFACE of it. But according to the Geologic Timescale it took millions of years to form those layers, so why is the erosion only on the surface, AFTER they were formed, but there is no erosion shown DURING that long period?

First of all, cross-bedding in the Coconino sandstone IS evidence of erosional forces acting on the sediment during its deposition. Ripple marks in river deposits are another example of the same kind of thing. No one here has said that no erosion happens to the sediment as it is being deposited even in the ocean. All that is required for sediment to accumulate is deposition greater then erosion. In an ocean or a lake erosion is extremely low so that is why sediment piles up there. On land sediment may pile up because erosion is low or because deposition is high. The Rio Grande Valley example that I gave before is a good example of this. The Sandia Mountains provide a ton of input and because a lot of it gets dropped into the valley it is hard to move it away. The end result is a net deposition of coarse alluvial fan deposits. River deltas are like this for a water environment. Lots of sediment is being moved but so much of it is also being brought in that you have a net deposition.

In particular, a disconformity is where the sediment has been re-exposed to erosion after being buried. This might not have been clear. Stuff piled up and then afterward was exposed to greater erosion which weathered it back down to some level.

I'd guess that these disconformities occurred between the layers after they were formed -- maybe after the one layer was laid down but the upper layer was not yet in place, or after the upper layer was in place, and in fact many layers above, as water would have continued to be pressed out between the newly formed layers for some time afterward and displaced some sediments in the process.

Once again, I doubt that even the most ambitious of YEC geologists would give something like this even a passing thought. At a disconformity often you can see that the rock is physically scarred from being stripped, is uneven, and is in drastic contrast to the rock that is further deposited upon it later. How is that supposed to happen after it is laid down?

This is already very long so I won’t burden you with more.

Thanks for the great discussion.


FOX has a pretty good system they have cooked up. 10 mil people watch the show on the network, FOX. Then 5 mil, different people, tune into FOX News to get outraged by it. I just hope that those good, God fearing people at FOX continue to battle those morally bankrupt people at FOX.
-- Lewis Black, The Daily Show

This message is a reply to:
 Message 95 by Faith, posted 04-03-2005 1:05 AM Faith has replied

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 Message 100 by Faith, posted 04-07-2005 4:10 AM Jazzns has replied

  
Faith 
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Posts: 35298
From: Nevada, USA
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Message 99 of 127 (197370)
04-07-2005 1:42 AM
Reply to: Message 97 by Admin
04-04-2005 1:50 PM


Re: Erosion between layers & unconformities
PS - If you're any good at graphic design, I need a new site logo.

No experience with it. Pretty good at drawing, and sometimes doodle on Paint. Just out of curiosity, however, I'd be interested in hearing what you have in mind for the new logo. I do know a couple of people who do graphic design, though I'm not really familiar with their work.


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Faith 
Suspended Member (Idle past 758 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 100 of 127 (197381)
04-07-2005 4:10 AM
Reply to: Message 98 by Jazzns
04-05-2005 1:07 PM


Re: Erosion between layers & unconformities
Basically your rebuttal to my statement that normal weather/erosion would disrupt the formation of any of the layers in formation is that it wouldn't, or at least it didn't. Not much of a rebuttal. Obviously it didn’t. That proves the whole thing was formed under water and the layers were NOT subjected to normal erosive processes for any great length of time.

A slope of thinness to thickness even to a great depth is not what I believe would be the result of normal weather processes. Remember I keep pointing out the VISIBLE STRAIGHTNESS or FLATNESS of the strata. A gradual slope is still straight and flat, certainly compared to what erosion over millions of years would do to it. I expect that it would have been disrupted in many many ways by normal erosion and weather effects OVER MILLIONS OF YEARS. More thickness in one place than another simply fits a Flood scenario in which more was deposited in one place than another and then smoothed down to relative flatness by the water action and the sediments that were laid down on top of it. Erosion over the millions of years assumed by the Geo timetable, on the other hand, would cut into it, not make a smooth gradual slope.

I’m going to send Percy another drawing to illustrate what I mean, a few layers laid down in water and not eroded, and then one exposed to weather after starting to be laid down in water. And in my opinion the actuality would be more drastic than the drawing. I try to show a couple of canyons being cut by water forming streams or rivers. The Grand Canyon itself was water cutting through over a mile of layered sediments, so why wouldn’t water runoff have cut through multiple layers at any point of exposure to surface weather over the postulated millions of years for each layer?

quote:
The whole point about original horizontality is that in a given spot a deposit will be horizontal with respect to the layers above and below it. If it is not horizontal with respect to itself 200 miles away then that is okay.

It’s OK with me too. I don’t get your point. What’s with all this quibbling about the OBVIOUS horizontality of the Grand Canyon strata? Honestly, of all things to dispute, to pick that is just incomprehensible. What ARE you trying to prove anyway? So there are minor deviations from perfect horizontal, and so there is erosion to a degree between the layers that doesn’t affect the overall horizontality, and so there are areas where parts of the whole stack have been tilted so that it’s not horizontal, but the layers are still parallel. What is it you are trying to prove? I really don’t get it. If you want to rebut my position you have to show that a million years of erosion of the surface of a single layer when exposed above water WOULD NOT disturb the horizontality or parallel configuration of the strata as I’m claiming it would.

How do you explain that canyons were NOT cut by running water through multiple layers of the canyon at any point in their formation – after three or four layers, after seven or eight, or each one at a time as it was exposed to weather? -- just as the Grand Canyon itself was later cut by water? ALL the canyons that were cut through those layers, not just the Grand Canyon but canyons to the north that are seen on the cross section diagrams, were cut AFTER ALL THE LAYERS WERE LAID DOWN, AFTER THE ENTIRE STACK WAS BUILT. Why? Why not IN BETWEEN???? My first drawing illustrates the effect I would expect in the finished column. I expect that such canyons WOULD have been cut, and then filled in by later sedimentation according to the long ages theory and that’s what I tried to illustrate (Edit: That's really not too likely to happen in reality, that it would be filled in by the next sediment, but for the sake of the discussion and a simple illustration I'm proposing it. It would have disrupted the horizontal appearance of the canyon walls either way). The drawing I’m going to send now is my idea of how a single layer would have been eroded during its millions of years of formation.

AGAIN, remember that we’re talking about MILLIONS OF YEARS for the formation of EACH LAYER, plenty of time for MANY canyons to form.

quote:
When we look at the GC, which is a cross section of the formation in one spot compared to the breadth of it across the area, it looks very nice in between the layers near it.

???”In between the layers near it”???

quote:
In a different location it might not even be between the same layers, at the same depth, of the same thickness, etc.

I would expect a variety of layers, that is, obvious discomformities, unconformities etc; it would fit a Flood scenario. It's the Geo timetable that has a problem with it, not I, but that's another subject. The subject of the moment is whether there is evidence of erosion within the individual layers, which I believe would have been so drastically disrupted by normal weather over millions of years the parallel layering would simply have been obliterated altogether. AGAIN, look at the cross section submitted by jar and the one I found. Here it is again. Scroll down the page:

N-S Cross section of Grand Canyon area up through Grand Staircase

The layers are depicted as remarkably parallel over a HUGE breadth of land to the north and east, and the formations of the Grand Staircase and canyons of Utah continue the extremely neat and consistent layers of the Grand Canyon to an enormous distance. I really don't know what you are trying to prove. The parallel formations are clearly the sort of thing that would have had to be laid down in water and NOT affected by erosion at ANY point in their formation if they were to retain that basic formation as they do.

quote:
Now let’s try to figure out what would happen to a desert full of sand dunes as it experiences the occasional El Nino. Sand at the very top will get wet and be blown around. Some new sand will be deposited by the extra weathering going on. Some sand that is already there will get blown away. When normal deposition resumes, the normal rates of deposition will determine if the sand that is now at the surface will continue to be buried or continue to be eroded depending on what is happening as a net average to that environment.

Part of the problem is that I think you are forgetting that, most of the time, land based deposits are continually eroded.


That's very funny since that's what I've been emphasizing. You’ve done this before, claimed I’ve overlooked the very thing I’ve in fact been emphasizing and basing my argument on. I don’t know how to account for this. Do you?

quote:
So yes, we do expect things like a hurricane or something to destroy something faster than it was already being destroyed if that was its erosional fate anyway. Most stuff on land gets eroded and ends up in the ocean or a lake. We do expect though that the minority of places like river valleys, basins, etc to be able to accumulate sediment and things like a hurricane are going to be more likely to help put stuff there rather than take stuff away.

I was simply listing many NORMAL weather patterns that normally occur over a year’s time in various parts of the world. Focusing on hurricanes or any particular pattern misses the point that overall they all make a mess of the topography even in a relatively short period, and then if you multiply that by millions of years you just don't have a flat layer any more, you have a very lumpy dippy surface with streams making channels in it and so on. I don't think you are addressing the point I'm trying to make at all.

quote:
So some places on land will be able to accumulate and preserve their deposits, especially if they then become inundated with water which is REALLY good at preserving deposits.

You betcha. Water is the ONLY thing that will give us the horizontal layers.

I'm only going to answer this much for now and ask Percy if he'll put up my second drawing.

This message has been edited by Faith, 04-07-2005 03:14 AM


This message is a reply to:
 Message 98 by Jazzns, posted 04-05-2005 1:07 PM Jazzns has replied

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 Message 102 by Jazzns, posted 04-07-2005 1:48 PM Faith has replied

  
Admin
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Message 101 of 127 (197413)
04-07-2005 9:18 AM
Reply to: Message 100 by Faith
04-07-2005 4:10 AM


Image Posted

Click to enlarge


--Percy
EvC Forum Director

This message is a reply to:
 Message 100 by Faith, posted 04-07-2005 4:10 AM Faith has not replied

  
Jazzns
Member (Idle past 3225 days)
Posts: 2657
From: A Better America
Joined: 07-23-2004


Message 102 of 127 (197473)
04-07-2005 1:48 PM
Reply to: Message 100 by Faith
04-07-2005 4:10 AM


What will erosion do to low places? What about those land deposits?
Basically your rebuttal to my statement that normal weather/erosion would disrupt the formation of any of the layers in formation is that it wouldn't, or at least it didn't. Not much of a rebuttal. Obviously it didn’t. That proves the whole thing was formed under water and the layers were NOT subjected to normal erosive processes for any great length of time.

In particular the GC this is mostly true. The only layer that is totally sub-aerial is the Coconino sandstone. The rest were oceanic marine deposits. The Coconino in particular was exposed to erosive forces by direct evidence of the cross-bedding in its matrix. The Coconino is wind blown sand, has an absence of marine life and presence of terrestrial life.

More thickness in one place than another simply fits a Flood scenario in which more was deposited in one place than another and then smoothed down to relative flatness by the water action and the sediments that were laid down on top of it.

What Flood scenario? You have yet to point at a flood scenario. I would also not expect a torrential flood covering the entire globe to smooth out anything let alone sort it in a reverse hydraulic fashion the first place. How would raging waters sort then smooth the Coconino sandstone? While your at it how about an explanation for how the flood would wind blow the sand, let animals walk around in it and make burrows, round the individual grains of sand like we see wind doing today but not water, and then lay down limestone on top of that?

Erosion over the millions of years assumed by the Geo timetable, on the other hand, would cut into it, not make a smooth gradual slope.

Like it does all the time you mean? Like the island topography in the middle of the canyon deposits? Like fresh water river channels in the middle of the geologic column?

http://home.entouch.net/dmd/rivchan.htm

In recent years, three-dimensional seismic data has become very common in the oil industry. Much like a CAT scan of the earth, fine details of the earth's structure can now be viewed in three-dimensional form. Features like deltas and river channels are now clearly seen meandering across a seismic volume. Figure 10 is a drawing of a river channel found on a seismic survey buried 1,670 feet deep in Baylor County, Texas.

...

When showing this to one friend, he asked if the river could be a buried pre-flood river? It can't. Most young-earth creationists believe that all the fossils were formed during the flood. There are several thousand feet of fossiliferous sedimentary rocks beneath this river channel and 1,600 feet of fossiliferous sediment above the channel. If all the fossils were a result of the flood then the river channel must also have been deposited during that year. But there is no time. The reason that the river channel is so visible is that the channel is incised into a limestone bed. In other words, over 5,000 feet of sedimentary rock was deposited before the Breckenridge limestone bed was deposited. After its deposition the river eroded the channel into the limestone. Nor could the erosion have taken place under the ocean. To erode the limestone in the fashion that it is eroded would require fresh water. The ocean is close to being saturated with calcium carbonate (lime), and so seawater would not easily erode a channel into limestone. This channel must have been deposited above sea level.

I’m going to send Percy another drawing to illustrate what I mean, a few layers laid down in water and not eroded, and then one exposed to weather after starting to be laid down in water. And in my opinion the actuality would be more drastic than the drawing. I try to show a couple of canyons being cut by water forming streams or rivers. The Grand Canyon itself was water cutting through over a mile of layered sediments, so why wouldn’t water runoff have cut through multiple layers at any point of exposure to surface weather over the postulated millions of years for each layer?

Simple, most of the time it was not exposed to weathering. How is water runoff going to cut limestone layers in the middle of an ocean.

As for the Coconino, it was weathered during its deposition as I have described before. Why it did not get cut up? I don't know but I also wouldn't be surprised if it was cut up in some places. I have yet to see any data about how the Coconino looks over the area of its deposition.

I also wouldn't be surprised if it was pretty continuous because we know a few things about it that point at an environment that would mean it had little exposure to drastic erosive forces. We know it was close to shore. We know where it was laid down was previously an ocean bottom. We know ocean bottoms are pretty flat and not too many canyons form off a gentle coast.

Also, if it had been exposed to erosional forces that would have cut it up those same erosional forces probably would not have allowed it to have formed in the first place. The fate of the GC is to be completely eroded because it is now high ground. I would not expect the GC to ever get buried again by new deposition. Most of the time this will be the case for a canyon. I would expect to see very few preserved canyons in any geologic column for the same reason. High erosion cuts canyons and that same high erosion usually prevents preservation.

How do you explain that canyons were NOT cut by running water through multiple layers of the canyon at any point in their formation – after three or four layers, after seven or eight, or each one at a time as it was exposed to weather? -- just as the Grand Canyon itself was later cut by water?

Once something is exposed to enough weathering to create a canyon I expect it to be weathered away. Since the GC was laid down in a coastal/ocean environment I don't expect many canyons to be slicing though a beach or reef.

ALL the canyons that were cut through those layers, not just the Grand Canyon but canyons to the north that are seen on the cross section diagrams, were cut AFTER ALL THE LAYERS WERE LAID DOWN, AFTER THE ENTIRE STACK WAS BUILT. Why? Why not IN BETWEEN????

Because it was not in an environment where a canyon would be cut. It was low ground on a gentle slope. The only time a canyon could have been theoretically cut would have been during a period of erosion which candidates are any of the disconformities in the GC. For all we know there WAS a canyon cut through it where that angular unconformity is in the canyon but when you get that much weathering usually most of it gets weathered away. Guess what, it did!

In between any other layers where there is no disconformity there would be no way to see any major erosional features because deposition never stopped. Periods of erosion are marked by disconformities so at most there could have been only a few chances for something to happen to the layers of the GC to alter its topography. Since it was pretty much a flat coastline the whole time it was being laid down (after the angular unconformity) we shouldn't expect to see a canyon or something like it cut into it. Of course unless you know of any canyons cutting through flat beaches?

My first drawing illustrates the effect I would expect in the finished column. I expect that such canyons WOULD have been cut, and then filled in by later sedimentation according to the long ages theory and that’s what I tried to illustrate (Edit: That's really not too likely to happen in reality, that it would be filled in by the next sediment, but for the sake of the discussion and a simple illustration I'm proposing it. It would have disrupted the horizontal appearance of the canyon walls either way). The drawing I’m going to send now is my idea of how a single layer would have been eroded during its millions of years of formation.

I certainly would not expect that. I would not expect a canyon or other major erosional features to form in a coastal environment. IN other environments we do see things like you propose. The islands and the river channel I showed you above are great examples of this. So once again we have the things that you say should be there which are actually there. They just aren't there for the GC in any drastic way because the GC is so unique. We do see erosional topography in the angular unconformity which you seem to think is not that big of a deal for a flood. In fact, the presence of that angular unconformity alone is evidence of exactly what you are asking just not in the way you would like to see it.

Another thing you should note is that we expect erosional surfaces to make things flat. Over "MILLIONS" of years of exposure to erosion a particular surface is in constant transition to becoming flat. Erosion makes things flat, deposition happens flat relatively to original topography (i.e. with respect to the other layers). Given these two facts, we would expect to see most sedimentary rocks to be flat which is exactly what we do see.

AGAIN, remember that we’re talking about MILLIONS OF YEARS for the formation of EACH LAYER, plenty of time for MANY canyons to form.

And eroded flat. The GC is pretty young in terms of geologic time. Give it a few dozen million years and it will be gone too.

I would expect a variety of layers, that is, obvious discomformities, unconformities etc; it would fit a Flood scenario.

You have yet to explain why you think it is obvious that unconformities would occur in the middle of a flood. To me they are a major problem for a flood because sediment needs to be laid down, harden, be eroded often by forces that are not water based (i.e. the glacier example in my last post), and the have deposition resume. How all of this is going to happen under water you need to explain.

It's the Geo timetable that has a problem with it, not I, but that's another subject. The subject of the moment is whether there is evidence of erosion within the individual layers, which I believe would have been so drastically disrupted by normal weather over millions of years the parallel layering would simply have been obliterated altogether.

Enough weathering to produce erosional features in the column usually is enough to also make sure the layers don't preserve. In some cases we DO SEE preserved instances of drastic erosional topography. Classical geology has no problem with why we occasionally find ancient freshwater river channels. A flood model certainly has big problems explaining why we would see any major erosional features happening in the middle of the flood at the same time that the sediments which are eroded are being laid down.

The layers are depicted as remarkably parallel over a HUGE breadth of land to the north and east, and the formations of the Grand Staircase and canyons of Utah continue the extremely neat and consistent layers of the Grand Canyon to an enormous distance. I really don't know what you are trying to prove. The parallel formations are clearly the sort of thing that would have had to be laid down in water and NOT affected by erosion at ANY point in their formation if they were to retain that basic formation as they do.

Your whole point seems to boil down to this disbelief that something can be exposed to erosion yet still form a sedimentary layer. I might just not be as clear as I need to be in my explanations but I will try again.

When erosion happens that causes sediment to go away, that environment will not produce a sedimentary layer. This is what I meant when I said that in order to make a sedimentary rock you need the net effect to be deposition rather than erosion.

When erosion happens that does not cause sediment to go away, that environment will produce a sedimentary layer. Environments where this will happen are low places like a basin. A canyon is not going to form at the bottom of a basin because rivers and other runoff do not go uphill.

When you are at a place that tends to collect sediment, any type of erosion going on is only going to further the deposition in that place. It is very difficult to remove sediment from the bottom of a low topographical area like a basin.

Take a bowl and anchor it to the ground somewhere outside and leave it there for a year. Let rain and wind act on it and after a year go and look at it. I am willing to bet that there is a layer of dirt inside that bowl. If it rains a lot where you live then you might even get a mini playa lake. Now turn the bowl upside-down and cover it with dirt. Wait a year and go look at it. I am willing to bet that most the dirt that you had piled on top of the bowl will be gone.

This may seem naive but I feel that this is the level where the communication is being disrupted. The properties that allow sedimentary layers to form in the first place also dictate that they will not be eroded away. You can almost say that this is the case by definition of a depositional environment. I think the reason this might not have been clear earlier is that no one who is trying to be honest will say that these places are not exposed to erosion. They simple are not exposed to the kind of erosion is that is going to take away sediment. The scenarios that you are describing simply cannot happen normally.

All this seems pretty basic to me so that might be why there is some confusion. If it is not basic to you then please tell me and we can keep digging deeper into the details.

1. Low places, erosion does not remove sediment, you get a layer.
2. High places, erosion does remove sediment, you cannot form a layer or layers are destroyed.

At any given time in any place on Earth it must be the case that one of those two things is happening.

That's very funny since that's what I've been emphasizing. You’ve done this before, claimed I’ve overlooked the very thing I’ve in fact been emphasizing and basing my argument on. I don’t know how to account for this. Do you?

With this, I just think that we are still talking past each other. There is a point in what I said which was not communicated correctly. You said that you expect all this erosion to be happening. My point was that you are right, it is happening. My point is also that on land the fate of most environments is to have their topography eroded away. But in some, topography is built up and these are the minority when talking about land. Of the places that are being eroded we will never see evidence of in the geologic column. The geologic column consists of only the things that have not been eroded away, by definition. This is exactly why sharp erosional features like a GC are not preserved in the column except in rare and unusual circumstances.

I was simply listing many NORMAL weather patterns that normally occur over a year’s time in various parts of the world.

Any kind of weathering, be it normal or drastic like a hurricane, will not remove sediment from a low place in any kind of substantial amount if even at all to create a drastic erosional feature. THAT IS the point.

Focusing on hurricanes or any particular pattern misses the point that overall they all make a mess of the topography even in a relatively short period, and then if you multiply that by millions of years you just don't have a flat layer any more, you have a very lumpy dippy surface with streams making channels in it and so on. I don't think you are addressing the point I'm trying to make at all.

I am addressing your point but just maybe not in the way that you would like which is one in which you are shown to be correct. Given that this is a relatively poor medium and we are necessarily at odds makes appropriate communication a constant struggle.

You point is that you expect to see a "lumpy dippy" surface with "streams making channels" even in a net depositional environment and that point is simply not correct. In a basin, if there are any streams they will empty into the basin not chop it up. These things will add to the deposition not take it away.

You betcha. Water is the ONLY thing that will give us the horizontal layers.

No, low places where sediment accumulates gives us horizontal layers. We see this today. We also see this in the geologic column in sediments that cannot have been deposited by water. This is the reason I brought up the issue of sediments that are very much land deposits which has yet to be addressed.

We know that the Coconino is a terrestrial deposit. From the location I listed before:
http://www.geocities.com/earthhistory/grandb.htm

The Coconino Sandstone (CS) consists of cross-bedded, well-rounded quartz grains. Most of the laminae are composed of climbing translatent strata and sand-fall strata. These are exactly the features we see in modern desert sand seas, such as the Sahara. Strahler explains:

"[D]esert dunes have distinguishing physical properties that set them apart from all other known forms of well graded sand deposits. The dune surfaces are devoid of plant cover and are formed into great wavelike ridges with sharp crests and steep lee slopes. The sand, usually almost entirely of quartz composition, is extremely well-graded in terms of size. The grains are spherical to a degree of perfection not found in water-transported sands. The grains surfaces are frosted by the force of intergrain impacts in free air, not subject to the cushioning effect that is found in water. Under prevailing strong winds, with dry conditions, the sand is carried up the windward slopes by low leaps and rebounds. Upon reaching the dune crest, the grains are projected into the air to fall in the comparitvie calm of the protected lee slope, where they build up the sand slope to a steeper angle of inclination. This slope is the slip face. At an unstable surface layer under gravity slides down the slip face until stability is resumed. This process, repeated innumerable times, gives the dune an internal structure or long, steep sand laminae. This structure is called dune bedding, or planar lamination" (p. 217).

...

The CS also preserves a variety of trace fossils which, like the sediment structure itself, are indicative of subarial deposition processes. For example, some laminae preserve perfectly formed raindrop prints (see figure 6 in Middleton et al, p.194). Also present are a variety of vertebrate (small reptiles, some possibly early mammal-like reptiles) and invertebrate (millipedes, spiders) trackways. Pictures of some of these traces and tracks can be seen here.
Hunt and Santucci note:

". . . Coconino tracks fall within three species of Chelichnus [also called Laoporus -- Lockley. ed.] [McKeever and Haubold, 1996]. Chelichnus is characterized by rounded manual and pedal impressions that are of nearly equal size and which exhibit five short, rounded toe impressions (though less than five may be preserved). Trackways have a pace angulation of about 90o and the manual and pedal impressions are close together [McKeever and Haubold, 1996]. The three valid species of Chelichnus are distinguished on the basis of size alone and are presumed to be the tracks of caseid-like animal [e. g. Haubold, 1971]. Chelichnus bucklandi has pedal impression lengths of 10-25 mm, C. duncani of 25-75 mm and C. gigas of 75-125 mm [McKeever and Haubold, 1996]" (Taxonomy and Ichnofacies of Permian Tetrapod Tracks from Grand Canyon National Park, 1998).

Similar trackway assemblages (ichnofaunas) are found in correlative Permian eolian deposits around the world, including the De Chelly Sandstone in Arizona, the Lyons Sandstone in Colorado, the Hopeman, Corncockle and Locharbriggs Sandstone Formations of Scotland, the Cornberger Sandstein of Germany, and the Los Reyunos Formation of Argentina (Hunt and Lucas, 1988a,b). Attempts by McKee, Brady and others to duplicate the tracks of the CS indicate that dry sand would have been necessary to retain the smallest of these trackways, such as those of spiders, to the level of detail they found to possess in the CS. Brady (1939, 1947) showed that modern analogues of the Coconino invertebrate fauna failed to leave any impression in sand which was even slightly moist, but that the same animals left clear impressions in dry sand (p. 185). McKee also performed a detailed study of the Coconino tracks, using a large trough and artificial sand dunes. Experiments with various vertebrates and invertebrates, using different levels of water saturation, confirm Brady's conclusion that many of the Coconino tracks were impressed into dry, loose sand. Others appear to have been impressed upon damp substrates.

Of course this poses the question which I have asked many times before of why tracks of any animal should be found in a layer produced in the middle of the flood in the first place? This is in particular in contrast to many YEC speculations that have the Coconino being deposited toward the end of the flood for other technical reasons. If the Coconino was deposited at the end then why were there animals walking around on the sand under water?

The question of evaporite deposits continues to get either an innocent dismiss or a purposeful dodge. Since I cannot tell by the absence of a response I'll leave the judgment to the readers. The only attempt by YECs to account for evaporites is to bank on this notion of evaporite purity which I have already shown to be absolutely false. That evaporites are not pure is a fact and not open to interpretation by anyone. Any flood model must explain why we see evaporite deposits in the middle of the geologic column in their impure state. These things are formed on land today by the countless filling and evaporation of playa lakes leaving behind an extremely thin layer of the saline content of the water behind. To get these deposits to build up in the thickness we see in the column you would have to have literally hundreds of thousands to millions of rain/evaporation cycles to produce them. Meanwhile life is going on dropping pollen and other indicators in the middle of these deposits. Nearby stratrigraphy gives other indications that they environment was eolean such as strata bearing mud cracks and other trace fossils.

Add on to this the biggest reason to negate any catastrophic formation of evaporites. We see them forming today with the product being exactly what we see deep in the column. We can go to playa lakes like Salt Lake and the Dead Sea and drill and find a gradient of deposition of halite and gypsum mixed in with all kinds of other sediments and traces of life. Then when we find the exact same thing somewhere in the middle of the column, why would we postulate that they were formed in any other method then the one that produces the exact same formations that we can watch growing!?!? If they were made in any different way, why would they look exactly the same? What is the simpler explanation?

If you want to postulate that the major portion of the geologic column was formed in the flood then you must take into account the evidence of deposits that point plainly to their being formed on land. If your whole argument rests on your belief that sediments accumulating on low ground ever loose their contents in any meaningful fashion then your argument simply collapses on itself. That is just plainly not what occurs based on direct observation. Places that get eroded like you suggest simply do not form sedimentary layers.

This message has been edited by Jazzns, 04-07-2005 10:50 AM


FOX has a pretty good system they have cooked up. 10 mil people watch the show on the network, FOX. Then 5 mil, different people, tune into FOX News to get outraged by it. I just hope that those good, God fearing people at FOX continue to battle those morally bankrupt people at FOX.
-- Lewis Black, The Daily Show

This message is a reply to:
 Message 100 by Faith, posted 04-07-2005 4:10 AM Faith has replied

Replies to this message:
 Message 103 by Faith, posted 04-07-2005 2:59 PM Jazzns has replied

  
Faith 
Suspended Member (Idle past 758 days)
Posts: 35298
From: Nevada, USA
Joined: 10-06-2001


Message 103 of 127 (197490)
04-07-2005 2:59 PM
Reply to: Message 102 by Jazzns
04-07-2005 1:48 PM


Re: What about those land deposits?
quote:
Basically your rebuttal to my statement that normal weather/erosion would disrupt the formation of any of the layers in formation is that it wouldn't, or at least it didn't. Not much of a rebuttal. Obviously it didn’t. That proves the whole thing was formed under water and the layers were NOT subjected to normal erosive processes for any great length of time.

In particular the GC this is mostly true. The only layer that is totally sub-aerial is the Coconino sandstone. The rest were oceanic marine deposits.


Look, I have been talking about this for some time and you have been mostly addressing topics peripheral to it. Leave the Coconino for now and please address the formation of the other layers, as you and others have said that while they were formed as oceanic sea deposits there were also MANY risings and fallings of sea level and SOME of the layers had SOME length of time above water in which they were exposed to weather in an aerial environment, AND, if I got this right, that these periods out of water explain the erosion that IS seen between certain layers.

Please let's stick to this topic. This has to be established first. I've been guessing that those that were exposed to air after having been laid down as marine deposits would have been so exposed for AT LEAST a very conservative million years out of the 20 or 50 million given for the total formation of a given layer, and unless I missed it you haven't said one word about this guess. Was it a million or ten million and which layers were so exposed to the air? What about the disconformities where it is believed that entire layers were eroded away? I've been mostly focused on this and have been claiming that during whatever time period it was, these layers would have been subjected to greater erosion than is present in any of them. This is what both my illustrations were designed to show. (As a matter of fact MANY things would have been different with such a scenario than what is actually observed but that's another subject).

Please address just this one point for now. I still have to get back to posts of yours prior to the one I just answered as well as the rest of this one.


This message is a reply to:
 Message 102 by Jazzns, posted 04-07-2005 1:48 PM Jazzns has replied

Replies to this message:
 Message 104 by Jazzns, posted 04-07-2005 4:37 PM Faith has not replied
 Message 105 by Jazzns, posted 04-07-2005 4:43 PM Faith has replied

  
Jazzns
Member (Idle past 3225 days)
Posts: 2657
From: A Better America
Joined: 07-23-2004


Message 104 of 127 (197514)
04-07-2005 4:37 PM
Reply to: Message 103 by Faith
04-07-2005 2:59 PM


Re: What about those land deposits?
The majority of the post you just responded to talk about exactly why we would expect erosion to occur just as we see it in the GC. If what I said is not clear then please ask specific questions because I cannot think of a better way to describe it other than what I just did.

To summerize.

Erosion tends to erode things flat.
Deposition tends to piles things up flat.

We see these things occurring today.

In places, including the GC, we DO find instances of drastic erosional features like the ones you are expecting to be there. I gave two examples of this. It just so happens that the particular layers of the GC that we have been talking about that this was not the case for them. This is part of what makes the GC such an interesting place for geologists. It is extremely well preserved.

I simply cannot think of what more you could want other than confirming evidence that exactly what you expect does occur plus an explanation for why the normal scenario is in contrast. Please ask specific questions.

Thanks,

{ABE I responded to the few specific questions in your post in a following post}

This message has been edited by Jazzns, 04-07-2005 01:44 PM

This message has been edited by Jazzns, 04-07-2005 01:50 PM


FOX has a pretty good system they have cooked up. 10 mil people watch the show on the network, FOX. Then 5 mil, different people, tune into FOX News to get outraged by it. I just hope that those good, God fearing people at FOX continue to battle those morally bankrupt people at FOX.
-- Lewis Black, The Daily Show

This message is a reply to:
 Message 103 by Faith, posted 04-07-2005 2:59 PM Faith has not replied

  
Jazzns
Member (Idle past 3225 days)
Posts: 2657
From: A Better America
Joined: 07-23-2004


Message 105 of 127 (197516)
04-07-2005 4:43 PM
Reply to: Message 103 by Faith
04-07-2005 2:59 PM


With regards to specifics.
Was it a million or ten million and which layers were so exposed to the air?

The only layer exposed to the air would be the one where the disconformity is present. The time span that is missing by the presense of the disconformity can vary from many thousands to many millions of years.

What about the disconformities where it is believed that entire layers were eroded away?

We diagnose missing layers by their presense in neighboring strata that happened not to be exposed to erosion in the same way. It is never assumed just from a disconformity alone what those layers were. A disconformity alone only tells us that after a period of deposition, a period of erosion erased whatever was on top of the rock up until depostion started again.

That the erosional unconformities of the GC are relativly flat is not suprising given that it is posed to have formed in a coastal environment. If you have a problem with this answer then please be specific why you have a problem.

THanks,


FOX has a pretty good system they have cooked up. 10 mil people watch the show on the network, FOX. Then 5 mil, different people, tune into FOX News to get outraged by it. I just hope that those good, God fearing people at FOX continue to battle those morally bankrupt people at FOX.
-- Lewis Black, The Daily Show

This message is a reply to:
 Message 103 by Faith, posted 04-07-2005 2:59 PM Faith has replied

Replies to this message:
 Message 106 by Faith, posted 04-07-2005 7:00 PM Jazzns has replied

  
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