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Faith  Suspended Member (Idle past 1444 days) Posts: 35298 From: Nevada, USA Joined: |
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Author | Topic: Deposition and Erosion of Sediments | |||||||||||||||||||||||||||
Faith  Suspended Member (Idle past 1444 days) Posts: 35298 From: Nevada, USA Joined: |
Simple topic: Sticking to the Grand Canyon at least for starters, because it is easy to visualize, it appears obvious to me that the individual strata are not eroded as roxrcool and others claim they are, as erosion over the millions of years designated for each of the layers would obliterate them, not leave them as neatly parallel/horizontal as they are. I'm sure some erosion can be demonstrated, but nothing like what should be expected from the millions of years assumed.
And no, when I say neatly I don't mean some kind of perfection. They LOOK parallel/horizontal to the naked eye. This should be a pretty limited topic, sticking to the specifics of the creation of a single layer of the Geo Column for the most part as suggested by Admin, but including how a given layer started from sediment and built up from the bottom to become rock and stayed relatively flat and horizontal over millions of years, which I claim is impossible.
{Edit note: I have changed the proposed topic title from "Objections to Evo Time Frame Deposition of Strata #2" to "Deposition and Erosion of Sediments". I have also removed Faith's previous "edited by" messages. - Adminnemooseus}
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crashfrog Member (Idle past 1466 days) Posts: 19762 From: Silver Spring, MD Joined: |
Sticking to the Grand Canyon at least for starters, because it is easy to visualize, it appears obvious to me that the individual strata are not eroded as roxrcool and others claim they are You may have noticed, perhaps, that there's a Grand F'ing Canyon running down through the layers? With a river down at the bottom? Where do you suppose that came from, exactly? Aliens? I don't see how a claim that erosion never occured could be in the least bit coherent with the existence of the canyon itself. Now if you're talking about non-river erosion, and you're certain that erosional rates exceed depositional rates, it would be nice if you could prove it with the numbers. AbE: Sorry, that came off as totally abrasive. Let me restate in the form of a question. When you say that you don't see any signs of erosion, are you talking about the erosional origin of the canyon itself, or erosion events prior to that, acting on the in situ sediment masses prior/post lithification? This message has been edited by crashfrog, 03-16-2005 01:15 PM
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Adminnemooseus Administrator Posts: 3974 Joined: |
I would love to see a clean, uncluttered topic happen here.
Personally (and many (most?) members disagree) I would like to see restraint used, it the number of quote boxes inserted. To me, such results in a "chopped up" effect. Again this is an "IMO". DO NOT RESPOND TO THIS MESSAGE IN THIS TOPIC. If you feel you need to respond, take it to one of the topics listed in my "signature". Adminnemooseus This message has been edited by Adminnemooseus, 03-16-2005 12:46 PM New Members should start HERE to get an understanding of what makes great posts.
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roxrkool Member (Idle past 988 days) Posts: 1497 From: Nevada Joined: |
Sticking to the Grand Canyon at least for starters, because it is easy to visualize, it appears obvious to me that the individual strata are not eroded as roxrcool and others claim they are, as erosion over the millions of years designated for each of the layers would obliterate them, not leave them as neatly parallel/horizontal as they are. I'm sure some erosion can be demonstrated, but nothing like what should be expected from the millions of years assumed.
Faith, you are looking at PHOTOGRAPHS. People who have worked on the rocks themselves, looked and studied the contacts see the erosive events. You simply cannot make that sort of call without ever having looked at the rocks themselves. Do some research on the Muav Limestone and the channels carved into the top of it. Those channels are filled with a fresh-water carbonate unit called the Temple Butte Limestone. Withing the Redwall Limestone formation, there is a low angle unconformity between the underlying Thunder Springs Mbr. and the overlying Mooney Falls Mbr. You cannot see these things in a photograph.
And no, when I say neatly I don't mean some kind of perfection. They LOOK parallel/horizontal to the naked eye.
Again, Faith, you are looking at photographs taken hundreds if not thousands of feet away from the rocks. While they ARE for the most part parallel and horizontal, they are also sub-parallel and sub-horizontal. THAT sort of detail you cannot see in a photograph.
This should be a pretty limited topic, sticking to the specifics of the creation of a single layer of the Geo Column for the most part as suggested by Admin, but including how a given layer started from sediment and built up from the bottom to become rock and stayed relatively flat and horizontal over millions of years, which I claim is impossible.
Large thickness of sediment can accumulate in basins by a process called basin subsidence. The weight of accumulating sediment causes the crust beneath the basin to deform and sink, thus providing ample accomodation space for continued basinal deposition. As long as the basin remains stable, it will continue to subside. The deeper the limestone gets, the more it's subjected to increasing temperatures and pressures, both of which are responsible for lithification. Cement, in the form of either calcite or dolomite (for carbonate rocks), is also responsible for lithification, and it is sourced from the same rocks (usually). As for how it remained horizontal, tectonics are usually responsible for tilting and/or deforming strata and if the basin was free of tectonic influences, little or no deviation from horizontal would occur. However, the presence of a low angle unconformity between the underlying Thunder Springs Mbr. and the overlying Mooney Falls Mbr. suggests tectonic movement and erosion preceding deposition of the Mooney Falls Mbr., which disproves your assumption that all the layers are perfectly horizontal and neat. (I stole and revised the above from my PNT topic.)
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Minnemooseus Member Posts: 3941 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: Member Rating: 10.0 |
I fear you have a very simplified view of what are sediment and sedimentary processes.
There are a large number of different sediment types and sedimentary environments. Vast amount of study time has been done on all this, ranging from using a microscope on up. Vast numbers of journal articles and thick books are the result. Whole university courses are devoted to specialized areas of sediments and sedimentation. And here we try to cover it all in an on-line forum. Indeed, a long history of deposition and erosion, repeated over and over, may well be the route to what is seen in the end. The marks of erosion and/or non-deposition may be large (Grand Canyon) or they may be very subtle. One example of a sedimentary environment is that of a river (referred to as the fluvial environment). In a modern river environment, the sediment of the river banks and flood plain continue to be re-eroded and re-deposited. What you see is the current (no pun intended) result, subject to further change. In either a modern example or an old now rock example, evidence of much of the process can be seen. Concerning limestones: The geo-clich is that limestones mean that nothing was happening. They are there because the was no tectonic activity in the area, and thus no detrital (fragmental) sediment was being brought in and deposited. They are the result of a very placid environment. Much of the limestone is directly or indirectly of biological origin - it is a graveyard of past life. Enough for now. Follow up questions welcome. Fellow geologist are welcome to harpoon me. Mellow Moose with a rusty geology degree Professor, geology, Whatsamatta U Evolution - Changes in the environment, caused by the interactions of the components of the environment. "Do not meddle in the affairs of cats, for they are subtle and will piss on your computer." - Bruce Graham
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jar Member (Idle past 393 days) Posts: 34026 From: Texas!! Joined: |
Would it be worthwhile to go into the fact that what we see today is simply the NET remaining deposit? If there is a layer that was laid down over 1 million years, what we see today is simply what remains after being deposited, compressed, eroded, moved and twisted?
The initial deposit may well have been considerably thicker and was subject to being deposited and eroded throughout the period. What remains is simply the NET difference between deposition and erosion. Is that correct? If a layer is (all simply asumed numbers for explanation) 1000 feet think and was supposedly laid down over 1000 years, that does not mean 1 foot per year but rather that deposition averaged 1 foot per year more than erosion. Is that correct? Aslan is not a Tame Lion
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Faith  Suspended Member (Idle past 1444 days) Posts: 35298 From: Nevada, USA Joined: |
Sticking to the Grand Canyon at least for starters, because it is easy to visualize, it appears obvious to me that the individual strata are not eroded as roxrcool and others claim they are You may have noticed, perhaps, that there's a Grand F'ing Canyon running down through the layers? With a river down at the bottom? Oh for crying out loud. This new thread is off to a RIDICULOUS start for you to say something that stupid. Over and over I have said that the ONLY VISIBLE erosion that we can all see with our own eyes happened AFTER the layers had built up over their supposed millions of years, the canyon itself. Good grief. What is the point if people can't follow that much of an argument.
Now if you're talking about non-river erosion, and you're certain that erosional rates exceed depositional rates, it would be nice if you could prove it with the numbers. We're talking about the INDIVIDUAL layers, or ONE individual layer for simplicity's sake. I am saying there is NO EVIDENCE OF EROSION on a single layer, which would certainly have obliterated it in its sedimentary form if it had been built up on DRY land over 20 million years. If you can't follow the argument get off the topic.
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pink sasquatch Member (Idle past 6022 days) Posts: 1567 Joined: |
I am saying there is NO EVIDENCE OF EROSION on a single layer, which would certainly have obliterated it in its sedimentary form if it had been built up on DRY land over 20 million years. If you can't follow the argument get off the topic. Hi Faith; it seems you are stating... "Sedimentary rock cannot form. It would be obliterated by erosion faster than its formation." If this is not accurate perhaps you can clarify your quote above.
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Minnemooseus Member Posts: 3941 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: Member Rating: 10.0 |
Depending on the environment, the degree of sediment reworking and movement can vary from little to none, to very extensive.
The previously mentioned fluvial environment is, of course, subject to massive reworking. Likewise a wind blown sand deposit (dune). A deep sea turbidite deposit, on the other hand, is much more isolated from erosional forces. Even in the absence of current reworking, there is such a thing as biological reworking (bioturbation). Think of how modern sediments are being churned by the life forms present. On a pre-Cambrian field trip, the professor commented on how someone else had commented that the there present tidal deposits contained the best preserved tidal structures he had ever seen. The reason? No life was present to bioturbate the sediments. A great example of the reworkings of sediments over a long time period, is found in quartzites (near 100% quartz sandstones). Not only is a lot of physical wear required to get rid of the other softer minerals, but the quartz grains themselves show a long history of wear. It take a lot of abrasion to round an originally angular quartz grain. Even more extreme is the example of quartz grains with abraded over growths. The grains were eroded and rounded and deposited and silica cemented into a hard rock. Then they were re-eroded, re-rounded, re-deposited, and re-cemented again into a new hard rock. Individual grains can be found, that show multiple cycles of this process. One question that is rarely touched on is, if vast amounts of the sedimentary rock pile were deposited in the short period of "the great flood", where did these sediments come from? It is a similar problem to "flood geology", as to where did the water come from. While mainstream geologic theory has no problem with the sediment source, "flood geology" seems to have to produce the sediments from who knows where. I once ran the "where's the sediments from" question past Tranquility Base. He proposed the concept of "catastrophic weathering". I likened that concept as being along the lines of two turtles having a catastrophic collision. Moose
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NosyNed Member Posts: 8996 From: Canada Joined: |
No, PS he is saying that he doesn't think any layer could build up over 20 million years on dry land. He didn't say (in fact has agreed that sediment can form under water)that sediment can not form.
I think I would like to know which layer it is that geologists are saying formed on dry land for 20 million years. Could you tell us which layer you are refering to Faith. I also think that the point made about net depostition needs to be understood.
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Faith  Suspended Member (Idle past 1444 days) Posts: 35298 From: Nevada, USA Joined: |
Faith, you are looking at PHOTOGRAPHS. People who have worked on the rocks themselves, looked and studied the contacts see the erosive events. You simply cannot make that sort of call without ever having looked at the rocks themselves. "Erosive events" that occurred over millions of years would have obliterated any layer in its formative stage. This is elementary logic. There would not be merely minuscule evidences of "erosive events" you'd have to examine the rocks to discover over such a period of ages, there would simply be not much of a layer left at all. As I've repeatedly said, what actual real erosion obviously does in the Grand Canyon area, is create the Grand Canyon itself.
Do some research on the Muav Limestone and the channels carved into the top of it. Those channels are filled with a fresh-water carbonate unit called the Temple Butte Limestone. Withing the Redwall Limestone formation, there is a low angle unconformity between the underlying Thunder Springs Mbr. and the overlying Mooney Falls Mbr. You cannot see these things in a photograph. Such minuscule observations of the strata are not required for the obvious effects real erosion would have caused during a period of twenty million years or so. That geologists take such evidences as in any way representing the actions of erosive processes during the building-up period of sediment-to-rock of a single layer over such long ranges of time is evidence only that geologists are in thrall to the false evolutionistic theory, and not thinking about the reality at all. If you require posters to take geology field trips and speak geologese here, it should be posted up front at this site so that we can stay away and you won't have to deal with mere logical thinkers without a degree in Geology. Or just don't post to us.
And no, when I say neatly I don't mean some kind of perfection. They LOOK parallel/horizontal to the naked eye. Again, Faith, you are looking at photographs taken hundreds if not thousands of feet away from the rocks. While they ARE for the most part parallel and horizontal, they are also sub-parallel and sub-horizontal. THAT sort of detail you cannot see in a photograph. So what? What would that prove that they aren't perfect? By my understanding of the supposed great times involved in their formation they should not have even the SLIGHTEST appearance of horizontal parallel rocks distinct from each other, except perhaps if they formed under water, and even then I have to ask how ONLY one kind of sediment was laid down over 20 million years and then ONLY another kind after that and so on. Here's where you can bring in your claim that Oh but there was tons of stuff on top of it once upon a time that got eroded away, and I can answer that there is no evidence of that and if that stuff got completely eroded away so would the RELATIVELY even strata beneath it, certainly before it became rock and how long does that take under water? Numbers please. Has this been observed? And wouldn't rock itself wear down visibly by normal weathering on dry land over so many millions of years? Remember it's exposed for that long a time, it's the surface of the column for that long a time given the aging method of the Geo Column hypothesis, and after all aren't you the one who insisted on the notion that the very rocky Rockies were completely eroded away twice?
This should be a pretty limited topic, sticking to the specifics of the creation of a single layer of the Geo Column for the most part as suggested by Admin, but including how a given layer started from sediment and built up from the bottom to become rock and stayed relatively flat and horizontal over millions of years, which I claim is impossible. Large thickness of sediment can accumulate in basins by a process called basin subsidence. The weight of accumulating sediment causes the crust beneath the basin to deform and sink, thus providing ample accomodation space for continued basinal deposition. As long as the basin remains stable, it will continue to subside. The deeper the limestone gets, the more it's subjected to increasing temperatures and pressures, both of which are responsible for lithification. Cement, in the form of either calcite or dolomite (for carbonate rocks), is also responsible for lithification, and it is sourced from the same rocks (usually). As for how it remained horizontal, tectonics are usually responsible for tilting and/or deforming strata and if the basin was free of tectonic influences, little or no deviation from horizontal would occur. What is your point? Which theory are you giving for the formation of a single layer of the Grand Canyon? Only it's lowest layers were tilted so why mention that at all?
However, the presence of a low angle unconformity between the underlying Thunder Springs Mbr. and the overlying Mooney Falls Mbr. suggests tectonic movement and erosion preceding deposition of the Mooney Falls Mbr., which disproves your assumption that all the layers are perfectly horizontal and neat. See above. This is a straw man representation of what I've been trying to say. It does not MATTER to what I'm saying that there are exceptions and imperfections. The OVERALL OBVIOUS VISIBLE IMPRESSION, certainly of the Grand Canyon, and in fact of all the extant portions of the Geol. Column throughout the world, is of NEAT HORIZONTAL LAYERS. How else would the evolutionistic idea of successive development of life forms through the fossil contents have occurred to anyone at all ever without this visible horizontal stratification? It's the very observation that STARTED the whole notion. And I read somebody's link at the other thread about the history of geology -- oh, no, it was a link on another thread that somebody resurrected, that gives "Steno's law" or something like that, in which he lays down generalizations that supposedly the field of geology still operates from, very common sense observations such as that an entire layer is a horizontal deposit over a large area, that the layers built up from the bottom over time etc. etc. etc. He also shows a layer in which erosion is considered to have occurred and "clasts" are supposedly the evidence of it. But it apparently involves the movement of one layer over the other in some unusual order rather than having been built up from the bottom in the usual fashion, and the erosion is minuscule compared to what one would normally reasonably logically expect would happen to any not-yet-rock sedimentary deposit over millions of years, at least in the atmosphere and not under water. I hope you can follow me. It is getting wearisome simply trying to get across what I'm talking about. Again, it would be nice if a forum allowed drawing pictures to illustrate. SO much quicker.
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NosyNed Member Posts: 8996 From: Canada Joined: |
Over and over I have said that the ONLY VISIBLE erosion that we can all see with our own eyes happened AFTER the layers had built up You may have said it but is it true that the erosion only happened after the layers were built up? You have only seen photographs. What real evidence are you using besides some tourist pictures? We should, perhaps, ask the geologists if there is any erosion of layers in the middle of the pile? The problem might be, Faith, that you are reaching conclusions without having all the evidence at hand. You can not make any firm statements about the Grand Canyon since you know nothing about it.
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Faith  Suspended Member (Idle past 1444 days) Posts: 35298 From: Nevada, USA Joined: |
Drat. Unfortunately I have a busy day today and tomorrow. Already there are posts to me I want to answer but I have to put it off. Sorry. And unfortunately I know there will be an overwhelming number more by the time I get back. Oh well. I have to leave for now. At least until late tonight.
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Adminnemooseus Administrator Posts: 3974 Joined: |
A most proper attitude!!!
Take the time you need, the others will wait. Hasty replies are a bad thing. BTW, you need not have replied to Crashfrog's above message. IMO it was out of line (note my reply to his message). Adminnemooseus
{Edited to change ID. I gotta go back to having the admin mode being the default} This message has been edited by minnemooseus, 03-16-2005 05:27 PM New Members should start HERE to get an understanding of what makes great posts.
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pink sasquatch Member (Idle past 6022 days) Posts: 1567 Joined: |
It is getting wearisome simply trying to get across what I'm talking about. Again, it would be nice if a forum allowed drawing pictures to illustrate. You can post pictures here. Hopefully this will be helpful to the discussion:
Faith - I guess I'm having trouble understanding-Are you proposing an alternative mechanism for the formation of the a single layer? If so, why is your mechanism more reasonable than what you are arguing against? Such minuscule observations of the strata are not required for the obvious effects real erosion would have caused during a period of twenty million years or so. The effects of real erosion produced the canyon, which I guess is pretty obvious (even though I hate that word). What you haven't addressed is why we would should expect the erosion rate to be the same a hundred yards into the wall of the canyon as it is at the site of the river itself. I think you really need to address a seemingly key issue with your argument - that, as Nosy mentions above, NET sedimentation is the issue, and produced the results we see. In other words, as long as the sedimentation rate is greater than the erosion rate, sedimentation will occur. You seem to be arguing that erosion would vastly exceed sedimentation across the entire landscape, not unlike it did in the formation of the canyon itself due to the erosive forces produced by the river. Do you have any evidence for a higher rate of erosion than sedimentation? If not, your argument seems to have little basis. This message has been edited by Admin, 03-17-2005 09:23 AM
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