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Author Topic:   Long build up of Sediments
Percy
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Posts: 22391
From: New Hampshire
Joined: 12-23-2000
Member Rating: 5.2


Message 166 of 180 (295741)
03-15-2006 9:22 PM
Reply to: Message 165 by Faith
03-15-2006 4:13 PM


Re: Title of thread is LONG buildup of sediments
Faith writes:
Percy writes:
What we can do is point out that the world has changed very little over the past 5000 years (limiting ourselves to the post-flood era). Europe and North America are moving apart at the rate of about 2 or 3 inches per year. That means that 5000 years ago these continents were around 2 miles closer, a tiny .1% closer of the 3500 distance.
You assume the rate now has always been the same.
We have evidence that the rate of sea floor spreading has always been roughly the same. That rate is about 2-3 inches per year for the Atlantic Ocean.
The first evidence is the sedimentation depth that increases gradually from the ridge to the continent. Had the rate changed from several miles per year to several inches per year, a change of nearly a 100,000 times, then the older stretch of sea floor where the rate had been fast would have noticeably less accumulation of sediment. You go on to say:
A creationist doesn't. In the beginning the rate may have been a few miles a year...
Keep in mind that this is a flood scenario, and that you raised it, not me. Since you raised this point I will reply to it, but I again suggest that if you do not want to discuss the flood scenario that you stop using it in your arguments.
If the sea floor had been moving at, let us say, 3 miles per year from 5000 years ago until 2000 years ago, and then after that at the rate of 3 inches per year, then sea floor that is 5000 years old would now be a distance of 1500 miles from the ridge on each side, and sea floor that is 2000 years old would be a distance of about a mile from the ridge. In other words, most of the ocean floor would be less than 5000 years old, because the continents aren't much more than 1500 miles from the ridge. Given the sedimentation accumulation rate of about a centimeter per century, it would mean that the sea floor that is about 1500 miles from the ridge should have a depth of sedimentation of about a yard or two. What is the actual depth of sediment at that distance? A mile or two. That's because sediment has been raining on the sea floor at the centimeter per century rate for millions of years.
Confirming evidence that the rate of sea floor spreading has always been slow is sea floor striping. This is where the sea floor produced at mid-oceanic ridges acquires a weak magnetic field in the same direction as the earth's magnetic field while it is cooling. I know the creationist response to this, but you said you didn't want to discuss the flood scenario, so if you don't introduce the creationist argument then neither will I. But we know with pretty great certainty that new sea floor has to cool before it can acquire a magnetic field (if you heat a magnet, it loses its magnetism), and that the magnetic field of the earth is locked in during the cooling process by being exposed to the earth's magnetic field over a relatively long stretch of time. New sea floor can only cool so fast, and so it takes time to acquire and lock in a magnetic field.
We also theorize that the earth's magnetic field is due to processes in the earth's outer core that are poorly understood at this time, but we do understand that it takes a considerable time for billions of tons of material to change their flow patterns. The earth's magnetic field reverses itself on average every half million years or so.
Radiometric dating is what gives sedimentation, sea floor spreading, magnetic sea floor striping and magnetic field reversals their absolute timescale. All applicable radiometric techniques agree that the sea floor of the Atlantic Ocean closest to the continents is millions and millions of years old. Radiometric dating tells us that the deepest sediments on the sea floor are also millions and millions of years old. Radiometric dates for sedimentary layers in the Atlantic Ocean correlate with the radiometric dates for the equivalent layers in all the other oceans.
The same is true for the magnetic field reversals. A sedimentary layer in the Atlantic ocean that is dated to 20 million years old will have the same magnetic field direction as a sedimentary layer from the Pacific ocean that is also dates to 20 million years old.
So you can see that we don't just assume the rate of sea floor spreading has always been the same. There is so much evidence for a relatively constant and slow rate that even if we didn't want to accept it, we'd pretty much be forced to.
But can you account for the LAYERS this way, the COMPLETELY DIFFERENT SEDIMENTS involved with their COMPLETELY DIFFERENT fossil contents?
Yes, of course. Ocean sediments far from coastlines are a reflection of the ocean life that lives above the sea floor and upon it. Areas of the ocean with a thriving ecology will accumulate sediments with high organic content, which would be limestone. Warm shallow seas are most noted for producing calcium carbonate rich deposits that will eventually become limestone.
An area of ocean that is receiving calcium carbonate rich sedimentary deposits and then is uplifted (but still under water) and finds itself not too far from a continental coast will begin to experience increased mud and silt that is delivered to the oceans by rivers and streams and from run-off. Though the calcium carbonate is still present, the mud and silt begins to dominate and now a sedimentary layer is forming that will eventually become a layer of shale.
As this area of ocean continues to uplift and becomes closer to the shoreline the heavier sand from rivers, streams and coastal runoff begins to dominate in the sediments deposited on the sea floor. The lighter mud and silt stays in suspension near the coastline and won't fall out of suspension until further from shore where it forms shale deposits, but the area of ocean we're considering is now right next to the coast and is receiving predominantly sand. The detritus from continents delivered into the oceans is immense, and sea floor near coastlines accumulates sediments at nearly five times the rate far out to sea.
Depending upon the ecology on and above the sea floor, the sediments also accumulate a record of the local sea life resident at the time. Some of the sea life is bottom dwellers, some are swimmers. Some are large, but many are microscopic. The changing life forms found in the layers are a record of both migration and evolution, but the older the sedimentary layer the more different those life forms are from modern life.
Then is it your theory that the sea floor periodically rises to the surface and forms new land? Wouldn't that make an awful LOT of the present land former sea floor? Is that the theory?
Marine sedimentary layers are found in many places around the world. By examining the sediments we can tell that except for being compressed and lithified into rock they are just like the limestone, shale or sandstone layers we can see being deposited in modern oceans today.
When we see marine layers on land we know that they used to be sea floor and that the area was submerged at one time and then uplifted. Or possibly the ocean levels fell, or possibly a combination. Remember that limestone layers form far from shore, shale layers closer to shore, and sandstone layers very near or at the shore. When we see repeated patterns of limestone, shale and sandstone layers we know that the area has gone through repeated periods of being far from shore, closer to shore, and very near or at the shore. By dating the layers you can actually reproduce and map how an ancient shoreline moved back and forth across a landscape.
That does seem to be the way most of the layers are thought to have formed. Mountainbuilding on the land is another but how much is thought to have come from that source, and again, does it exhibit the layering of different sediments and different fossil contents?
Mountain building does not create layers. It can only lift up and elevate layers. In the Alps and Himalayas you can find marine deposits on mountain peaks. And since mountains are the most exposed geologic forms on the landscape, they are also the most quickly eroded. Twenty or thirty million years is all it takes to erode a mountain range the size of the Alps to nubs (assuming uplift is no longer present - the Himilayas are being eroded at a fair clip, but they're being uplifted even faster), and all the sedimentary layers that filled them flow back to the oceans in rivers, streams and continental run-off.
And how do the depths of the present-forming sediments in either case compare with those {ABE: OF THE LAYERS} in the geo column, including the ideas of course about how {ABE: THE LAYERS} in the geo column may in fact have been originally much much thicker than they now are?
You're asking a question about a point you were discussing with someone else. I'm not quite certain of the point the other person was trying to make, so let me describe this in my own way.
An unconformity is a boundary between two adjacent geological layers where the lower layer was eroded away to some degree before the upper layer was deposited. An example of this happening would be a shoreline area with deep standstone deposits, lets say a couple hundred feet or so. A combination of a drop in ocean level and an uplift of the area leaves this layer a couple hundred feet above sea level, and erosion removes a hundred feet of the sandstone, which isn't really hard sandstone yet since it hasn't ever been deeply buried and so has never had too great a weight upon it. Even so, it will take a considerable period to erode away a hundred feet of soft sandstone because the top quickly acquires a layer of dirt and then of flora which protect it.
Maybe it takes a couple hundred thousand years to erode away a hundred feet of sandstone, and then rising ocean levels and/or subsidence sink the area once again beneath the waves. This is a substantial drop this time, and the area finds itself far from shore and a thousand feet below sea level. Suddenly our sandstone is beneath a shallow sea, and very shortly a rain of calcium carbonate begins from the skeletons of microscopic creatures living and dying in the waters above. A limestone layer begins to form atop the sandstone.
One thing you might be able to tell from this scenario is that we can't really know how much sandstone was eroded away. I said a hundred feet in my example, but what if only a foot of standstone had been eroded way, or what if hundreds of feet of sandstone had been eroded away. We can't know how much because it is no longer there. If we come back as junior geologists millions of years later, we can see the uncomformity between the sandstone layer and limestone layer just above it, but the material that was eroded away is nowhere to be found. We can't know how much sandstone used to lie above the unconformity boundary.
Sometimes we do know how much was eroded away because the same layer exists some distance away where it was never uplifted above sea level and so was never eroded away. I don't really know how often this is the case.
So an unconformity tells us that material has been eroded away, but it doesn't tell us how much. It could have been a foot of material, it could have been thousands of feet of material.
To answer your question about how well the layers found in the geological column correspond to contemporary layers forming today, the answer is that except that they've been compressed and lithified into rock, they're identical. Of course there are differences in fossil types according to age and geographical region, and there can be mineral differences due to local or special circumstances in some layers, like the high iron oxide content of layers thought to correspond to when oxygen became a significant presence in the atmosphere, but otherwise the limestone, shale and sandstone layers forming today are identical to those of yesteryear.
--Percy

This message is a reply to:
 Message 165 by Faith, posted 03-15-2006 4:13 PM Faith has replied

Replies to this message:
 Message 167 by Faith, posted 03-18-2006 12:37 AM Percy has not replied

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


Message 167 of 180 (296419)
03-18-2006 12:37 AM
Reply to: Message 166 by Percy
03-15-2006 9:22 PM


Re: Title of thread is LONG buildup of sediments
That is a very impressive post, Percy, deserving of your POTM, and of course most of it I can't answer.
But I have a few overall observations and questions about it.
We have evidence that the rate of sea floor spreading has always been roughly the same. That rate is about 2-3 inches per year for the Atlantic Ocean.
The first evidence is the sedimentation depth that increases gradually from the ridge to the continent. Had the rate changed from several miles per year to several inches per year, a change of nearly a 100,000 times, then the older stretch of sea floor where the rate had been fast would have noticeably less accumulation of sediment.
I'm not following this. Presumably the continents are riding on, or riding along with, the spreading sea floor, so "the older stretch of sea floor" is the stretch closest to the continents, which is where one would expect the maximum accumulation under all circumstances. It would seem logical to me that during or right after the Flood when the continents split, at that point we might expect a lot of accumulation from the sides of the continents, no? In fact I would guess that over time the rate would slow down. I would also guess that the gradual diminishment of the depth of sediments from the continents out toward the ridge would just be the natural spreading effect of the continuously depositing sediments. I really don't see how your scenario explains anything. Doesn't demonstrate a constant rate of deposition that I can see for one thing.
You go on to say:
A creationist doesn't. In the beginning the rate may have been a few miles a year...
Keep in mind that this is a flood scenario, and that you raised it, not me. Since you raised this point I will reply to it, but I again suggest that if you do not want to discuss the flood scenario that you stop using it in your arguments.
That's fine. I acknowledge that I raised it and if I raised it before and forgot, I apologize.
If the sea floor had been moving at, let us say, 3 miles per year from 5000 years ago until 2000 years ago, and then after that at the rate of 3 inches per year, then sea floor that is 5000 years old would now be a distance of 1500 miles from the ridge on each side, and sea floor that is 2000 years old would be a distance of about a mile from the ridge. In other words, most of the ocean floor would be less than 5000 years old, because the continents aren't much more than 1500 miles from the ridge.
Yes, that's true (although from a flood perspective a gradual slowing is what would have been expected from the start of it.)
Given the sedimentation accumulation rate of about a centimeter per century, it would mean that the sea floor that is about 1500 miles from the ridge should have a depth of sedimentation of about a yard or two. What is the actual depth of sediment at that distance? A mile or two. That's because sediment has been raining on the sea floor at the centimeter per century rate for millions of years.
Or because there was very fast accumulation for some period just after the continents split, and a higher rate than you posit all along, although gradually slowing down over the last 5000 years. You don't know the rate of accumulation. You said it was known, but how can it be known? All you can know is the rate NOW. But I see you will go on to discuss this further.
Confirming evidence that the rate of sea floor spreading has always been slow is sea floor striping. This is where the sea floor produced at mid-oceanic ridges acquires a weak magnetic field in the same direction as the earth's magnetic field while it is cooling. I know the creationist response to this, but you said you didn't want to discuss the flood scenario, so if you don't introduce the creationist argument then neither will I. But we know with pretty great certainty that new sea floor has to cool before it can acquire a magnetic field (if you heat a magnet, it loses its magnetism), and that the magnetic field of the earth is locked in during the cooling process by being exposed to the earth's magnetic field over a relatively long stretch of time. New sea floor can only cool so fast, and so it takes time to acquire and lock in a magnetic field.
We also theorize that the earth's magnetic field is due to processes in the earth's outer core that are poorly understood at this time, but we do understand that it takes a considerable time for billions of tons of material to change their flow patterns. The earth's magnetic field reverses itself on average every half million years or so.
Well, I'm aware of the magnetic striping but not up on the arguments, and although yours may be quite logical I'm sure the creationists' is too, so I hope you won't mind if I simply reserve this one for some other time.
Radiometric dating is what gives sedimentation, sea floor spreading, magnetic sea floor striping and magnetic field reversals their absolute timescale. All applicable radiometric techniques agree that the sea floor of the Atlantic Ocean closest to the continents is millions and millions of years old. Radiometric dating tells us that the deepest sediments on the sea floor are also millions and millions of years old. Radiometric dates for sedimentary layers in the Atlantic Ocean correlate with the radiometric dates for the equivalent layers in all the other oceans.
At any rate of sedimentation over such supposed millions and millions of years, there shouldn't be any land mass left at all I would think; it should all have dissolved into the oceans.
So now you are going to go on to the layering of the sedimentation, and I just want to orient myself: didn't this originally come up as an answer to my "incredulity" about how the geo column could have formed? Depth of sediment you can show, but you have to show the different layers of different sediments, not to mention different fossil contents, which it appears you can answer in the following, but then there's also the question if you are expecting the sea floor to accumulate sediments periodically and then rise to form land mass, in order to account for the geo column effect? How feasible is the idea that much of the existing geo column was formed by rising ocean deposits like this?
The same is true for the magnetic field reversals. A sedimentary layer in the Atlantic ocean that is dated to 20 million years old will have the same magnetic field direction as a sedimentary layer from the Pacific ocean that is also dates to 20 million years old. So you can see that we don't just assume the rate of sea floor spreading has always been the same. There is so much evidence for a relatively constant and slow rate that even if we didn't want to accept it, we'd pretty much be forced to.
I get your reasoning more or less.
But can you account for the LAYERS this way, the COMPLETELY DIFFERENT SEDIMENTS involved with their COMPLETELY DIFFERENT fossil contents?
Yes, of course. Ocean sediments far from coastlines are a reflection of the ocean life that lives above the sea floor and upon it. Areas of the ocean with a thriving ecology will accumulate sediments with high organic content, which would be limestone. Warm shallow seas are most noted for producing calcium carbonate rich deposits that will eventually become limestone.
An area of ocean that is receiving calcium carbonate rich sedimentary deposits and then is uplifted (but still under water) and finds itself not too far from a continental coast will begin to experience increased mud and silt that is delivered to the oceans by rivers and streams and from run-off. Though the calcium carbonate is still present, the mud and silt begins to dominate and now a sedimentary layer is forming that will eventually become a layer of shale.
As this area of ocean continues to uplift and becomes closer to the shoreline the heavier sand from rivers, streams and coastal runoff begins to dominate in the sediments deposited on the sea floor. The lighter mud and silt stays in suspension near the coastline and won't fall out of suspension until further from shore where it forms shale deposits, but the area of ocean we're considering is now right next to the coast and is receiving predominantly sand. The detritus from continents delivered into the oceans is immense, and sea floor near coastlines accumulates sediments at nearly five times the rate far out to sea.
So you think that horizontal layers can be formed (and preserved in their horizontal state) through periodic "uplifting" of the ocean floor. How often does such uplifting occur in actuality -- is it known or merely hypothesized to occur? -- and by what means, and wouldn't there be more apparent graduation (mixing of sediments) in the layers to the naked eye than we see in the geo column if this is how it formed?
This is all interesting, however, and makes me wonder about similar processes in the Flood.
Depending upon the ecology on and above the sea floor, the sediments also accumulate a record of the local sea life resident at the time. Some of the sea life is bottom dwellers, some are swimmers. Some are large, but many are microscopic. The changing life forms found in the layers are a record of both migration and evolution, but the older the sedimentary layer the more different those life forms are from modern life.
That's logical. However, shouldn't the layers beneath the sea reflect the same existent geo column that is now considered to reflect the great ages of the earth? It sounds like you are describing a more recent accumulation of material rather than something that parallels the supposed ages of the column. Where are the time periods in these layers under the sea? How old are the sediments according to the OE understanding? Shouldn't those farthest from the ridge (closest to the continents) reflect whatever period is normally dated to the age of those?
Then is it your theory that the sea floor periodically rises to the surface and forms new land? Wouldn't that make an awful LOT of the present land former sea floor? Is that the theory?
Marine sedimentary layers are found in many places around the world. By examining the sediments we can tell that except for being compressed and lithified into rock they are just like the limestone, shale or sandstone layers we can see being deposited in modern oceans today.
When we see marine layers on land we know that they used to be sea floor and that the area was submerged at one time and then uplifted. Or possibly the ocean levels fell, or possibly a combination. Remember that limestone layers form far from shore, shale layers closer to shore, and sandstone layers very near or at the shore. When we see repeated patterns of limestone, shale and sandstone layers we know that the area has gone through repeated periods of being far from shore, closer to shore, and very near or at the shore. By dating the layers you can actually reproduce and map how an ancient shoreline moved back and forth across a landscape.
I'd like to see such a map. But again this suggests massive shifting between or reversals of what used to be ocean floor and what used to be land mass.
That does seem to be the way most of the layers are thought to have formed. Mountainbuilding on the land is another but how much is thought to have come from that source, and again, does it exhibit the layering of different sediments and different fossil contents?
Mountain building does not create layers.
Well I believe it was roxrkool who said it does, so I will leave that to her or whoever said something along those lines.
It can only lift up and elevate layers. In the Alps and Himalayas you can find marine deposits on mountain peaks. And since mountains are the most exposed geologic forms on the landscape, they are also the most quickly eroded. Twenty or thirty million years is all it takes to erode a mountain range the size of the Alps to nubs (assuming uplift is no longer present - the Himilayas are being eroded at a fair clip, but they're being uplifted even faster), and all the sedimentary layers that filled them flow back to the oceans in rivers, streams and continental run-off.
But LAYERS is what we want to see.
And how do the depths of the present-forming sediments in either case compare with those {ABE: OF THE LAYERS} in the geo column, including the ideas of course about how {ABE: THE LAYERS} in the geo column may in fact have been originally much much thicker than they now are?
You're asking a question about a point you were discussing with someone else. I'm not quite certain of the point the other person was trying to make, so let me describe this in my own way.
An unconformity is a boundary between two adjacent geological layers where the lower layer was eroded away to some degree before the upper layer was deposited.
And there may not be any actual physical evidence of erosion, or merely minimal signs of such erosion -- this is really mostly just the idea that this other layer "should" have been there according to the idea about the ages of the geo column, isn't it?
An example of this happening would be a shoreline area with deep standstone deposits, lets say a couple hundred feet or so. A combination of a drop in ocean level and an uplift of the area leaves this layer a couple hundred feet above sea level, and erosion removes a hundred feet of the sandstone, which isn't really hard sandstone yet since it hasn't ever been deeply buried and so has never had too great a weight upon it. Even so, it will take a considerable period to erode away a hundred feet of soft sandstone because the top quickly acquires a layer of dirt and then of flora which protect it.
Maybe it takes a couple hundred thousand years to erode away a hundred feet of sandstone, and then rising ocean levels and/or subsidence sink the area once again beneath the waves. This is a substantial drop this time, and the area finds itself far from shore and a thousand feet below sea level. Suddenly our sandstone is beneath a shallow sea, and very shortly a rain of calcium carbonate begins from the skeletons of microscopic creatures living and dying in the waters above. A limestone layer begins to form atop the sandstone.
One thing you might be able to tell from this scenario is that we can't really know how much sandstone was eroded away. I said a hundred feet in my example, but what if only a foot of standstone had been eroded way, or what if hundreds of feet of sandstone had been eroded away. We can't know how much because it is no longer there. If we come back as junior geologists millions of years later, we can see the uncomformity between the sandstone layer and limestone layer just above it, but the material that was eroded away is nowhere to be found. We can't know how much sandstone used to lie above the unconformity boundary.
Sometimes we do know how much was eroded away because the same layer exists some distance away where it was never uplifted above sea level and so was never eroded away. I don't really know how often this is the case.
So an unconformity tells us that material has been eroded away, but it doesn't tell us how much. It could have been a foot of material, it could have been thousands of feet of material.
To answer your question about how well the layers found in the geological column correspond to contemporary layers forming today, the answer is that except that they've been compressed and lithified into rock, they're identical. Of course there are differences in fossil types according to age and geographical region, and there can be mineral differences due to local or special circumstances in some layers, like the high iron oxide content of layers thought to correspond to when oxygen became a significant presence in the atmosphere, but otherwise the limestone, shale and sandstone layers forming today are identical to those of yesteryear.
OK I'll just leave all this as it is just too much to think through. Thanks for your time.

This message is a reply to:
 Message 166 by Percy, posted 03-15-2006 9:22 PM Percy has not replied

Replies to this message:
 Message 174 by DBlevins, posted 03-19-2006 8:19 PM Faith has not replied

  
Dubious Drewski
Member (Idle past 2530 days)
Posts: 73
From: Alberta
Joined: 02-04-2006


Message 168 of 180 (296559)
03-19-2006 2:00 AM
Reply to: Message 7 by Faith
03-10-2006 5:56 PM


I'm very sorry, Faith. I have much respect for you, but you are showing qualities that reveal you to be a perfect example of a dogmatic person.
I don't see the point in continuing this, or any, argument with someone dogmatic. It is impossible.
Whenever someone brings up a strong point, you either do not respond or you claim ignorance. I'm sorry, but I just do not like seeing people do that.
Then again, I also hate to see someone's faith attacked. I'm unsure if I should 'root' for you or not. But that's off-topic.

This message is a reply to:
 Message 7 by Faith, posted 03-10-2006 5:56 PM Faith has not replied

  
lfen
Member (Idle past 4677 days)
Posts: 2189
From: Oregon
Joined: 06-24-2004


Message 169 of 180 (296561)
03-19-2006 2:40 AM
Reply to: Message 25 by Faith
03-11-2006 8:46 AM


Faith,
My apologies on not getting back to your reply sooner. I've been having some serious computer hard drive problems. I'm temporarily running on an old obnoxiously noisey HD as I try and decide where to go (I'm hoping to put off purchase of a new system for about a year to allow me to evaluate Windows Vista and it's requirements and impact on computing).
Geology is not a major interest of mine and it seems like other folks are doing a better job than I could do so I won't say much. Your objections are understandable but I believe if you explored the literature you would find them addressed.
For example:
But about the fastest rate of deposition I can come up with, even given kilometers of depth accumulated in the usual millions of years alloted to a given layer, is still only about a maximum of a foot a year and I don't see how even that rate would favor fossilization.
My understanding is that fossilization is indeed as you observed not favored. Fossil result from unusual circumstances where an animal dies in an environment that results in quick burial such as rapidly silting river bends.
As to the changes in strata I thought that reflected whether the area was underwater or lifted about water or subject to volcanic activity.
The history of palentology that I'm familiar with, though it's been many years, was that the initial discoveries of fossil were hailed as the result of the flood. But as more exploration was made that hypothesis couldn't be supported.
But I'll bow out of this discussion as I go back to fussying with this computer.
lfen

This message is a reply to:
 Message 25 by Faith, posted 03-11-2006 8:46 AM Faith has replied

Replies to this message:
 Message 170 by edge, posted 03-19-2006 11:57 AM lfen has not replied
 Message 171 by Faith, posted 03-19-2006 12:10 PM lfen has not replied
 Message 172 by roxrkool, posted 03-19-2006 12:14 PM lfen has not replied

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


Message 170 of 180 (296586)
03-19-2006 11:57 AM
Reply to: Message 169 by lfen
03-19-2006 2:40 AM


My understanding is that fossilization is indeed as you observed not favored. Fossil result from unusual circumstances where an animal dies in an environment that results in quick burial such as rapidly silting river bends.
As to the changes in strata I thought that reflected whether the area was underwater or lifted about water or subject to volcanic activity.
The history of palentology that I'm familiar with, though it's been many years, was that the initial discoveries of fossil were hailed as the result of the flood. But as more exploration was made that hypothesis couldn't be supported.
A very good synopsis, hopefully distilled to the point where Faith cannot avoid understanding it. The details that we've gone into here have simply been lost...

This message is a reply to:
 Message 169 by lfen, posted 03-19-2006 2:40 AM lfen has not replied

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


Message 171 of 180 (296589)
03-19-2006 12:10 PM
Reply to: Message 169 by lfen
03-19-2006 2:40 AM


My understanding is that fossilization is indeed as you observed not favored. Fossil result from unusual circumstances where an animal dies in an environment that results in quick burial such as rapidly silting river bends.
This does not appear to account for the actual disposition of fossils scattered throughout the strata.
As to the changes in strata I thought that reflected whether the area was underwater or lifted about water or subject to volcanic activity.
You have to have a lot of these ups and downs in the case of some deep stacks.
The history of palentology that I'm familiar with, though it's been many years, was that the initial discoveries of fossil were hailed as the result of the flood. But as more exploration was made that hypothesis couldn't be supported.
Yes, but they had some very strange ideas about the flood in the old days so what they falsified was just a straw man.
But I'll bow out of this discussion as I go back to fussying with this computer.
Well I'm trying to stay out of it myself.

This message is a reply to:
 Message 169 by lfen, posted 03-19-2006 2:40 AM lfen has not replied

Replies to this message:
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roxrkool
Member (Idle past 988 days)
Posts: 1497
From: Nevada
Joined: 03-23-2003


Message 172 of 180 (296591)
03-19-2006 12:14 PM
Reply to: Message 169 by lfen
03-19-2006 2:40 AM


I've mentioned this before, but the degree of fossilization required for 'preservation' is different between terrestrial and marine settings - and I'm assuming the foot sedimentation/year was in the marine setting.
In terrestrial settings, special circumstances greatly improve the chances of preservation for a land organism. However, in the marine setting, there is a constant rain of sediment onto the ocean floor, many of the marine organisms have hard shelly parts that do not decompose or disintegrate except under certain conditions. Of course it doesn't hurt for marine fossils to become replaced by sulfide or another mineral, but that is not as necessary for marine fossils as it is for terrestrial fossils.
In some rocks, bivalves can look as fresh as those you find on the beaches today, so for Faith to use the argument that such slow rates of sedimentation will not preserve marine fossils is meaningless.
In addition, I'm not sure if Faith has any idea of how fossils appear in marine rocks. How many fossils does she thing we find? Some rocks are highly fossiliferous, but many others are basically fossil-poor, but go to a beach and you can find places where empty shells accumulate because of waves. There are some formations that always seem to contain a lot of fossils over large aerial extent, while others are virtually fossil-free.
Another thing Faith does not understand is that the rocks are a highly compacted representation of the original sediments. I can't remember what the average percentage of compaction is for marine rocks, but I would guess somewhere upwards of 75%. So if the original sediments were 100 feet thick with fossils scattered throughout, compaction would result in a 25 foot thick assemblage. This process will break up the fossils, flatten them, and concentrated them - making them appear very close together when originally they were not.
This message has been edited by roxrkool, 03-19-2006 12:17 PM

This message is a reply to:
 Message 169 by lfen, posted 03-19-2006 2:40 AM lfen has not replied

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


Message 173 of 180 (296597)
03-19-2006 12:42 PM
Reply to: Message 171 by Faith
03-19-2006 12:10 PM


Ifen: My understanding is that fossilization is indeed as you observed not favored. Fossil result from unusual circumstances where an animal dies in an environment that results in quick burial such as rapidly silting river bends.
Faith: This does not appear to account for the actual disposition of fossils scattered throughout the strata.
Actually, it does. Note the inclusion of 'unusual circumstances' in Ifen's post. Also, one of those circumstances that Rox referred to is that marine fossil tend to be preferred. This makes a lot of sense.
Ifen: As to the changes in strata I thought that reflected whether the area was underwater or lifted about water or subject to volcanic activity.
Faith: You have to have a lot of these ups and downs in the case of some deep stacks.
Indeed, that is what we see. In the sequence I'm working on right now, there are at least three major transgressions and regressions of the sea. And that is just one small formation in the late Cretacesous.
I just drilled through a thick regressive sandstone with very sparse shell fossils, mostly fragmented and jostled. But once in a while, we see a thin shelly bed where several fossils are found neatly arrayed side by side, still mostly disarticulated, but looking like a deposit sorted by wave action. Just the way they appear on modern beaches.
Ifen: The history of palentology that I'm familiar with, though it's been many years, was that the initial discoveries of fossil were hailed as the result of the flood. But as more exploration was made that hypothesis couldn't be supported.
Faith: Yes, but they had some very strange ideas about the flood in the old days so what they falsified was just a straw man.
Please document. How strange? What was this strawman idea of the flood? How is it different from your concept of the flood? How does your idea of the flood account for faunal/floral progression? For instance, how does your flood model explain the presence of angiosperms only very late in the fossil record? I guess this should probably be done in a separate thread, but I eagerly await your explanation in the future.

This message is a reply to:
 Message 171 by Faith, posted 03-19-2006 12:10 PM Faith has not replied

  
DBlevins
Member (Idle past 3775 days)
Posts: 652
From: Puyallup, WA.
Joined: 02-04-2003


Message 174 of 180 (296663)
03-19-2006 8:19 PM
Reply to: Message 167 by Faith
03-18-2006 12:37 AM


Re: Title of thread is LONG buildup of sediments
At any rate of sedimentation over such supposed millions and millions of years, there shouldn't be any land mass left at all I would think; it should all have dissolved into the oceans.
This is a misconception. Over these "supposed" millions of years land masses are being built as well as being eroded. It isn't just one process - erosion. Continental crust is being formed by colliosion events with other continental crusts and oceanic crusts. The difference being that oceanic crust is heavier/denser than continental crust so it subducts under the continent. As the oceanic plate subducts, it melts (in the simplist terms) forming volcanism which is the source for more continental crust. ie. volcanoes are formed on the continent and are eroded away. Some of the sediment on the seafloor is also folded and metamorphosed by this kind of collision (like scrapping butter from a slice of bread) forming even more land, which is subsequently eroded over time.
So now you are going to go on to the layering of the sedimentation, and I just want to orient myself: didn't this originally come up as an answer to my "incredulity" about how the geo column could have formed? Depth of sediment you can show, but you have to show the different layers of different sediments, not to mention different fossil contents, which it appears you can answer in the following, but then there's also the question if you are expecting the sea floor to accumulate sediments periodically and then rise to form land mass, in order to account for the geo column effect? How feasible is the idea that much of the existing geo column was formed by rising ocean deposits like this?
I am going to answer the bolded section as it relates to the question you posed above and was answered somewhat above as well. Some Oceanic sediments are folded and metamorphosed as they are scrapped off by the continental crust as the oceanic crust subducts under the continent. These former oceanic sediments "build-up" as they are scrapped off to form something called a "melange" such as the Francisco melange.
(edited to fix quote box.
This message has been edited by DBlevins, 03-19-2006 08:20 PM

This message is a reply to:
 Message 167 by Faith, posted 03-18-2006 12:37 AM Faith has not replied

  
tanzanos
Inactive Member


Message 175 of 180 (296812)
03-20-2006 1:55 PM


Whats the problem?
I don't really know what all the fuss is about. Every time an ice age came to an end; great flooding occured with the melting of the glaciers(some 2 klm high). The last ice age ended when humans had the ability of language thus through the spoken word the recolection of the floods was handed down through the generations until it became mythology and or part of a religion. There is not enough water on this planet to cover all the land masses. The hypothesis that God flooded the whole planet and a boat harbored a pair of every known animal is childish to say the least. Imagine Noah trotting off to the antartic to gather polar animals then off to Asia for some more animals etc. etc. Instead of debating whether sedimentation occours in such a period of time etc. One need only to look at the 2 sides in order of time spent in scientific research (worldwide) in comparrison to a few pages of a book written in a time when most people believed the world was flat and take this as proof contradicting the scientific side.
This is good material for a COMEDY!

Mighty is the sword that draws blood!
Mightier is the Pen that draws ink!
Mightiest is the tongue that draws ears! (Yiannis Mantheakis)

Replies to this message:
 Message 176 by Faith, posted 03-20-2006 2:36 PM tanzanos has replied

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


Message 176 of 180 (296826)
03-20-2006 2:36 PM
Reply to: Message 175 by tanzanos
03-20-2006 1:55 PM


Re: Whats the problem?
The hypothesis of many ice ages, the myth about myths of the flood, and the certainties about what is possible water-wise without a shred of evidence, only the imagination of Modern Man, all that sure IS comedy. And that one doesn't even have the evidence of being written down in any ancient texts, while Noah's flood does. Chortle.

This message is a reply to:
 Message 175 by tanzanos, posted 03-20-2006 1:55 PM tanzanos has replied

Replies to this message:
 Message 177 by crashfrog, posted 03-20-2006 4:53 PM Faith has not replied
 Message 178 by NosyNed, posted 03-20-2006 5:09 PM Faith has not replied
 Message 180 by tanzanos, posted 03-21-2006 10:53 AM Faith has not replied

  
crashfrog
Member (Idle past 1466 days)
Posts: 19762
From: Silver Spring, MD
Joined: 03-20-2003


Message 177 of 180 (296858)
03-20-2006 4:53 PM
Reply to: Message 176 by Faith
03-20-2006 2:36 PM


Re: Whats the problem?
The hypothesis of many ice ages, the myth about myths of the flood, and the certainties about what is possible water-wise without a shred of evidence, only the imagination of Modern Man, all that sure IS comedy.
Ice ages happen.
People tell myths.
Can you explain what you find funny about the idea that these two things, which we all know happen, happened in the past? I find that a lot more reasonable than the idea that something that has not ever been observed and would seem to be impossible on the face of it, actually happened.

This message is a reply to:
 Message 176 by Faith, posted 03-20-2006 2:36 PM Faith has not replied

  
NosyNed
Member
Posts: 8996
From: Canada
Joined: 04-04-2003


Message 178 of 180 (296868)
03-20-2006 5:09 PM
Reply to: Message 176 by Faith
03-20-2006 2:36 PM


Starting to cross a line.
without a shred of evidence
At certain points continuing to repeat this when you have had a chance to learn otherwise moves from ignorance to willfull ingnorance to simple dishonesty.
I'm not sure what the consequences of playing fast and loose with one of the ten commandments but I'm sure you're more aware than I. Perhaps you should consider what statments you make more carefully. I know that you are going beyond wrong now even if new comers don't.
Obviously there is no common ground that allows for actual dialogue between the irrational and others. Bye.

This message is a reply to:
 Message 176 by Faith, posted 03-20-2006 2:36 PM Faith has not replied

  
Admin
Director
Posts: 12998
From: EvC Forum
Joined: 06-14-2002
Member Rating: 2.2


Message 179 of 180 (297026)
03-21-2006 9:21 AM


Forum Guidelines Warning
First, I regret I couldn't continue to participate as Percy in this thread. It takes a while to compose long posts, and I simply ran out of time.
Second, please everyone keep in mind that you must support your positions with evidence. Even the position that there is no evidence must be supported by pointing out why the other side's evidence is not really evidence, or by describing how that evidence might have been misinterpreted.
Third, please, even when someone is obviously not following the letter or the spirit of the Forum Guidelines, stay with the guidelines yourself.
Thanks!

--Percy
EvC Forum Director

  
tanzanos
Inactive Member


Message 180 of 180 (297053)
03-21-2006 10:53 AM
Reply to: Message 176 by Faith
03-20-2006 2:36 PM


Re: Whats the problem?
By stating that there is no written account of the Ice age floods and that the account of Noah is written borders on the ridiculous. The last Ice age ended before man had a WRITTEN language. Scientific evidence proves the Ice ages existed. You have no proof! Your only proof is based on faith. Faith is not Proof. A few pages in the Bible on Noah compared to the millions of pages in Scientific texts on the Ice ages is something that should not even be considered. Millions of scientists have toiled in order to understand physical reality and you come along and insist that they are wrong. Well all I can say is I sincerely hope you reconsider your ideas before they become law and once again we will witness the burning of witches in public squares.

This message is a reply to:
 Message 176 by Faith, posted 03-20-2006 2:36 PM Faith has not replied

  
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