Long build up of Sediments

Well, how fast are limestones being deposited today? I'm beginning to think you don't read my posts, even though I try to make my responses short. Two words: plate tectonics. I know that this is only and ad hoc explanation for you, but extreme vertical movements are quite realistic. Something to think about. Do you think that fossils are being deposited today? If so, where is the global flood? Another thing to think about. At very high rates of sedimentation, as required by some flood geology scenarios, how do you develop such things as burrows and termite nests, etc., during feet per day rates of sediment accumulation? Yes, I am a catastrophist. Let's look at sand dunes, for instance. How much of the time do you think that actual, permanent deposition is occurring? I'd say for every dune in the geologic record, several or tens or hundreds might have been eroded away by wind. Can you see this? I'm not sure why this is a problem. Are you some kind of uniformitarianist who says that depositonal environments cannot change?

So, you are saying that igneous and metamorphic basement rocks (the foundation of the crust) were formed by a flood? Please explain. I was only responding to the other poster. PLease describe the characteristics of a flood deposit and why you see them everywhere. You seem quite confident of your geological expertise.

I acknowledge that there are problems for the flood model, but my focus here is on the problems with the slow sedimentation over 4 billion years model. Oh right, and you can tell from that just how many feet of sediment that accumulated over just how many millions of years is now missing? Not much is really rapid and it only can be considered rapid after assuming the erosion of huge quantities of sediment and maybe reducing the time of deposition to a very very tiny time period out of the millions of years the layer is labeled with, and even then the deposition doesn't seem fast enough to permit fossilization as I've been trying to figure it out here. And it's only natural you would want to needle me with an off topic bit about the flood when the subject is YOUR theory of hundreds of millions of years of slow deposition of sediments that keep themselves neatly separate from each other and have no known reasonable source. Again, I am not focusing on the flood, but raising questions about YOUR theory, a theory which is totally absurd if one thinks about it at all (and hey Purpledawn, if he can call me sophomoric I can call him absurd). Well, how many out of those kilometers of depth of deposition of precisely differing sediments over hundreds of millions of years can be described as having been rapid, AND, rapid enough to permit fossilization???This message has been edited by Faith, 03-11-2006 09:30 AM

Igneous rocks are volcanic, right? Volcanic activity is considered to have been initiated with the Flood.I too am responding to the other poster, by responding to you. But I can go respond to her directly. The idea that the flood has to be searched for is silly when the whole geo column, this stack of different sediments full of fossils, is obviously the evidence for the flood.Stratification is what I see everywhere.

Perhaps my definition is a bit off, but yes. No. They would have been deposited in the appropriate environment, pelagic, continental, etc. Deposition is a process. It leaves behind information that we can understand and use to interpret geologic history. No. Most terrigenous (from the land) sediments never make it very far out into the sea. They vary in composition from their source to the deepest parts of a basin. Oh, lots of things. Climate change, mountain building, sea level changes... Some probably, but I didn't mean to be any specific erosional process. Good, show us some examples. I think that is because you confuse erosion with deposition. They are two different processes.

Some of them. What is the mechanism for this? And why do we have volcanos now? Fine, that is your opinion, but it doesn't make much sense. So all stratified rocks are flood deposits? What do you see in stream beds, beach sands and other deposits occurring in the present?

What does this have to do with how I calculated the rate of deposition? I chose limestone at random. Could have chosen anything else in the Grand Canyon wall. Oy. Actually, no I don't think they are being formed except under unusual conditions here and there, nothing like what would add up to the quantities we see all over the earth even in a billion years. Yes, another problem for the flood scenario while you evade the problem for your scenario. Tell me how you expect fossilization to occur at the rates of sedimentation you postulate. Even assuming this I don't get rates of sedimentation fast enough to permit fossilziation. What on earth does this have to do with what I just said? I'm saying that a conspicuous apparently sudden change from one completely uniform/homogeneous sediment to another over tens of millions of years beggars explanation. How it stayed so uniform for those years and then how it was suddenly absolutely totally replaced by Something Completely Different.

The release of the "fountains of the deep" suggests the opening of the ocean floor which released volcanoes. They continue today because the ocean floor remains open.Stream beds and beach sands don't anywhere near suggest the kind of layering that we see in the geo column. To the extent that they could be taken as a model they would tend to support the flood idea, the movement of different kinds of sediments in different waves or currents of water, on a similar principle to the stream bed but on a much greater scale.
======================================================
abe: Must be gone for a while.This message has been edited by Faith, 03-11-2006 09:47 AM

I have to jump in here. Faith wrote:

quote:

---

Again, the more I think about this, the more difficult it becomes to imagine where such an incredible depth of sediments could have come from under the gradual accumulation theory. Kilometers of depth?

---

Here's something to think about, Faith: If we accept, as you argued yesterday, that the global Flood was only 15 cubits (~7 meters) deep, how could it have deposited sedimentary layers several kilometers thick? Please address this, as I would be very interested in hearing an explanation for this.

quote:

---

The rate of deposition affects the plausibility of fossilization, for one thing, which requires more than just burial to prevent decomposition, which is a pretty rapid process under most conditions. What all it requires I'm not sure, compression at least I think, oxygen depletion perhaps?

---

All that, yes. Anoxic environments help to prevent decomposition. And finally, diagenesis/lithification.

quote:

---

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.

---

First, let's clear up another misconception you seem to hold to: Fossilization is not common. We may have found hundreds of thousands of fossils, maybe even millions, but this is only a fraction of what would have once been alive on earth. You yourself just admitted above that it takes some very special conditions for fossilization to occur (rapid burial in fine sediment, anoxicity, etc.) Typically, dead bodies don't get covered in sediment and are left to decompose in the elements.
Second, your above logic fails because you keep making reference to 'average deposition rates' within an entire sequence. These rates do matter with regards to fossilization. What matters is the rate of deposition at the time the fossil was burried. Say I bury a corpse under two feet of sediment within a year, and then the rate of deposition in the area drops off to just a few centimeters a year for the next hundred years (say, due to retreating sea levels). If you average out the overall depositional rate within the entire deposit, it might seem to you that the average rate of deposition is not enough to favour fossilization, but you should be able to recognize that this isn't the case.

The problem is that if you have one coral reef, it throws out your whole young earth scenario. Actually, we have thousands of them at different levels in the record. And then there are the other rock types... My experience says you are wrong. What about shells buried in beach sands being deposited today? OKay, how long does it take to make a footprint (a trace fossil)? Then you have to deny that creatures lived on the bottom of the sea in burrows and mounds and coral reefs. These could not have existed in the rates of deposition you seem to prefer. Just emphasizing the importance of lost time in the record. WEll, how much change have we seen in the continental shelf depostion over the last 2000 years? Virtually none. Now suppose sea level changed altering the entire pattern of deposition. It has happened, by the way. Numerous time. Just because you don't see the change has little to do with the certainty that things have changed.

It does? Where is this spelled out? And you are the one complaining about sheer speculation...And just when was/will be the ocean floors 'closed'? Aren't you speculating here? Really? So there are no beach sands or stream deposits in the geologic record? What do you see in the stratigraphic column? And where do you see this great scale of deposit? What is it?

I think Edge's answer may have been too short and too technical. The answer itself is very simple. Much of the material in sedimentary layers is eroded off the continents. Wind and rain gradually erode even the highest mountains down to nubs, and the eroded material is carried by streams and rivers to lakes and oceans where it is deposited on the bottom.You asked if this is speculation, and the answer is no. Rivers deliver tons and tons of sediments to the oceans every day. The deltas that snake out into the oceans from river mouths are proof enough, but scientists can actually calculate how much is delivered by sampling the water to see how much sediment is suspended and by measuring the flow rate of the river. For example, the Mississippi river delivers about 300 million cubic yards of sediment to the Gulf of Mexico every year. That's equivalent to a block of material about 2/5 of a mile per side. For reference, the Empire State Building is about 1/4 of a mile tall. That's a lot of sediment, and that's just one river. Other rivers do the same, though most don't deliver as much sediment as the Mississippi, and rain and storms deliver even more sediments to the oceans in the form of runoff at all points along the coast. Erosive forces of sea and ocean on beaches and cliffs contributes still more sedimentary material.The material delivered to the oceans from the continents by these erosive forces does not immediately fall to the bottom, especially if it is fine grained. Heavy materials like everything above the size of a sand grain fall out of suspension to the bottom relatively rapidly, unless the water is turbulent, but the remaining suspended material is sustenance for ocean life. The smallest organisms, such as algae, consume it directly, often as part of the process of photosynthesis. The tinyest life is consumed by larger life and so on up on the food chain. When life dies in the ocean it is consumed by other life and what remains is eventually deposited on the ocean floor with the rest of the sediments.How long has this process been going on? Well, scientists take sedimentary cores and measure this. A sedimentary core is a cylinder of material drilled directly out of the ocean floor. They're usually around 4 or 5 inches in diameter and around 10 yards in length before being cut up into more managable sections once on deck. These cores reveal that the depth of sediments near the mid-oceanic ridge where new sea floor is being continuously created is nearly non-existent, but as you move toward the continents the depth grows deeper and deeper. This means that the youngest sea floor is at mid-oceanic ridges, while the oldest is near the continents where the greatest depth of sediments are found.Studies of these sedimentary cores reveal that on average ocean basins receive around 3 or 4 inches of sediment every 1000 years, but it varies widely. Sedimentation is naturally faster near continents, because that's where the sediment comes from. Remote areas of the oceans with little life deposit sediments at the slowest rates, since there is little continental contribution and there is little life to die and contribute to the sediments. But what the cores everywhere reveal is that sedimentation is gradual.What is it about the sedimentary cores that tells us this? It is the fine grained nature of the sedimentary material. When we look at the top foot or so of sediments, the material deposited over the last 3 or 4 thousand years, we see the same fine-grained sediments that we see being deposited today. This means that these same sedimentary processes were operating 1000 years ago, 2000 years ago and 3000 years ago.But what do we see when we look at the second or so foot of sediments, the material from around 3000 to 7000 years ago? We see the same thing - fine grained sediments. And in the third foot or so of sediments containing material from around 7000 to 11,000 years ago? We see more fine grained sediments.This tells us that the same processes depositing sediments on ocean floors today have been operating in the same way and at very near the same rates unchanged for thousands and thousands of years.Another way to confirm the slow rate of deposition is to date the cores at different depths, and there are a variety of ways to do this. Radiocarbon dating is one, but there are others. For example, significant volcanic events leave their traces in the sedimentary deposits, as the Pompey volcano Vesuvius did - you can find ash from the Vesuvius eruption of 79 AD in sediments at the bottom of the Mediterranean buried about 8 inches deep, the exact depth of course varying according to where you take your sample.In your flood scenario you describe it as denuding continents to produce the sediments we find. This proposal has a few serious problems. Such denuding would leave copious evidence everywhere. Sedimentary cores on land would constantly be finding the "flood denudation boundary". There's also the question of where the original material on the continents came from that the flood denuded. The earth was young, no deep sediments had had time to be deposited, and there was no earlier flood to create them.Another serious problem for the global flood is the complete absence of flood deposits in the ocean sedimentation record. The boulders and trees and rocks and other large objects from the denuded continents just aren't anywhere to be found in any sediments from any ocean at any depth.But the most serious problem for a global flood from a sedimentation standpoint scenario is the lack of sorting of the sediments. As anyone who has added a few tablespoons of garden dirt to a glass of water can attest, the heaviest material settles out first. If you wait a few days you'll find the water clear and the very top level of sediment to be extremely fine grained. Pebbles will be at the bottom. Were the geologic column a result of the global flood then we would expect to see precisely the same effect. The largest and heaviest material would be in the deepest layers, and the lightest and smallest material would appear at the top.But we don't find anything that resembles that at all. Sandstone layers have much larger grains than limestone layers, and yet the geologic layers have sandstone atop limestone in quite literally dozens and dozens and dozens of places.This is the kind of thinking that occurred to the first geologists who systematically studied the geologic record. Though originally believing that the flood created the geologic record, even with the paucity of evidence available during the 18th and 19th centuries it was evident that a flood could not leave fine-grained sedimentation or the alternating pattern of fine-grained and larger-grained layers.--Percy

This seems to be one of the major issues that you bring up. It's a good point, and it should be addressed fully.from wiki:

quote:

---

Deposition, also known as sedimentation, is the geological process whereby material is added to a landform. This is the process by which wind, water, or ice create a sediment deposit through the laying down of granular material that has been eroded and transported from another geographical location.

---

Sediment doesn't immediately harden and become rock, it remains loose, compressing the layers beneath it, which to simplify things seems to result in a layer of sedimentary rock. The rate at which this sediment increases is slow, and it moves around. Fossilization of soft bodied creatures occurs when some of this sediment is moving somewhat rapidly (example a mud flow, or the creature dies and sinks to the bottom of a river (where we know sediment is moving rapidly)).My understanding then is that sediments move rapidly in a short period of time, cover an animal and then settle and gradually get more and more buried under more sediments. I'd imagine this is the kind of thing that might happen at river bends where sand banks form. Eventually the river would stop depositing sediments in that area (rivers change course), and another form of sedimentation might occur. If I am understanding this correctly, it would mean that there would be two different types of sedimentary rock (layers) from this kind of scenario.The sediments are slow in their forming, but can be moved around quite rapidly before they mineralize (is that the right term?)Can anyone out there care to tell me if I am barking up the right tree on this?

In message 19 Faith asked: This is a massively good question, and one that I don't recall ever previously encountering from a creationist. Indeed, it's rare for even the evolution side to raise that point. I was about to raise the point myself, and found that Faith had beat me to it!Now, others have covered the answer already, so I will not. But I will say that the question is not a problem in the old Earth time frame, but it certainly is in the young Earth time frame.Skipping ahead, Faith (in the message this is a reply to) says: Now, we could quibble over what is really meant by the term "geologic column", and such has been done elsewhere in earlier topics. But as Faith uses the term, "geologic column" seems to mean the entirety of the Earth's continental crust. Faith seems to think that the vertical sequences of rock of the Earth's crust are the same everywhere. This is very wrong, but again is not a detail I wish to here explore.What I will focus on it the two quoted statements. Faith asserts "The entire geologic column was formed by the flood. THAT's the beginning and end of the flood." Now, the entire so called "geologic column" is not all sedimentary rocks (a Faith flood problem in itself), but a big part of it is. So I turn Faith's own question back on her.How does Faith explain where all the sediment comes from that has piled up to such a depth? Faith is seemingly saying that the flood has reworked the entire pre-existing continental crust into what is currently the form of the continental crust. And if indeed such is the case, what was the nature of the Earth's "geologic column" prior to the flood?May have to later transplant this discussion into the Faith/Moose "Great Debate" topic, which BTW I did do a recent minor reply to recently.POTM soon coming to Faith, for that question quoted at the top of this message.Moose

---

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

​

"The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness." - John Kenneth Galbraith

​

"I know a little about a lot of things, and a lot about a few things, but I'm highly ignorant about everything." - Moose

You appear to have a mistaken impression of what 'fossilization' actually looks like and what is required in marine or terrestrial settings.In order for fossilization to occur in the terrestrial setting, life forms do generally need to be buried quickly or they will likely be eaten and the skeleton scattered. The best fossils we have of land-. dwelling organisms are usually ones that have fallen into a stream or lake bed and quickly buried, buried in the desert, died in a location with few predators or scavengers, got stuck in a mud hole or quick sand or tar pits, or even frozen and covered by snow.In the marine setting, organisms don't require mineralizing fluids in order to be preserved. Anything on the bottom of the ocean is simply covered eventually and it helps that sea life has a lot of hard and bony parts. Shells are particularly easy to preserve, worms are not. So we see a lot of shells, teeth, bones, coral, sponge spicules, etc., but little shark or fish bodies, worms (except for evidence of burrowing), or other soft bodied organisms. Plants can be common, too.We can find shell material that looks like it was buried yesterday that still has its pearly irridescence. Mineralizing fluids can replace shell material, but it is not required for preservation.