Let's see what you stated:
Faith writes:
I've explained it many times in the past. It has to do with the idea that one particular kind of sediment and only that kind of sediment could have been slowly deposited, small increment by small increment day by day month by month, year by year over millions of years, and remain only that one particular kind of sediment spread over some great horizontal area, say the entire Southwest US covering four or five states, where we see all the fantastic layered formations and know that those layers are continuous over all that area, each its own peculiar sediment.
This is wrong. Rarely are sediments pure. Occasionally we have pure chalks, or pure limestones, or pure sandstones, but the majority of time, they are mixed and interlayered with other sediment types.
If you are arguing for flood deposition, you have a long way to go. The first seds to be deposited during a flood would be those with the highest specific gravity, meaning boulders, cobbles, sand, etc. would all deposit first before silt, clay, and carbonate or siliceous oozes. Therefore, limestone and dolomite, shale, and mudstone would all occur at the top of a geologic column deposited via a catastrophic flood.
In fact, I would expect to find sedimentary layers rich in magnetite, titanium, zircon, diamond, garnet, diopside, gold, platinum, ilmenite, and all the other heavy minerals. In California each year in Spring, people flock to the Sierras to pan gold because the Spring rains carry gold that has eroded out of the rocks by the Summer rains and winter frosting action. Erosion resulting from the catastrophic rains would surely free up some significant amounts of highly valued economic minerals. Surely.
Wonder why the Creationists haven't looked into this mega-Bonanza sedimentary horizon...?
And each sediment, so clearly different from a sediment below and above for quite a huge stack of sediments, dozens, all different from each other, a limestone here, a different limestone there, a sandstone, a shale, and so on and so forth, all originally laid down as sediment, most of it underwater in that region I understand, though presumably this could also be an aerial process, so I've heard tell around these parts, just bit by bit over millions of years.
Yes, so how WOULD a catastrophic flood's water chemistry change so dramatically as to first deposit a calcium carbonate and then a phosphorite or a calcium magnesium carbonate?
And no, neither carbonate nor shale are deposited subaerially. They require water.
I guess one could sort of accept that nothing but one kind of sediment could get deposited in that way over millions of years, sort of, but then you have to understand that apparently quite abruptly the whole scenario shifts and then not that sediment, not that same sediment at all, but an entirely new sediment starts being deposited, and is homogeneously deposited over another few million years, many millions according to some notions of what time period it supposedly represents, and everybody acts like this is perfectly normal, could have happened that way, does indeed reflect bazillions of years of deposition teeny bit by teeny bit --
but it is not reasonable at all to think it could have happened that way.
In mainstream geology, this is explained using the facies concept, which is a three-dimensional model representing depositional environments. And these days, stratigraphic interpretations of marine rocks are analyzed and studied within a eustatic framework (sea level changes over time) using sequence stratigraphic techniques.
In other words, the changes we see in the rocks are the result of relative changes in sea level. Rising sea levels cause continental flooding, like what would happen in Florida and other low-lying coastal areas if the ice sheets melted. Falling sea levels would result in retreating seas, which would likely re-exposed the Bering Land Bridge and increase continental areas.
This causes the various depositonal environments, such as the beach, near-shore, shallow platform, etc. to move landward. So basically, beach sands migrate landward, as does the carbonate platform, and the deeper shale environment. The weight of the sediment causes the wet sediments to compact and also the ground underneath to subside/sink. That's why sediments can accumulate to great depths. If the opposite happened and the ground instead started rising, erosion would take over and no sediments would be able to accumulate.
Falling sea levels result in a seaward migration of depositional environments. The beach sands will move back towards the sea and because the land sinks underneath the wet sediments, the sands start depositing on what was once the carbonate platform, so you get beach sandstone over carbonate. Further back, you have carbonate depositing above shale and so forth.
Changes in climate can cause increased terrestrial erosion and a subsequent increase in clastic input (into the marine environment). And if this happens in a place where carbonate is being deposited, carbonate precipitation will cease or slow down and can either result in sand deposition (sandstone) or a calcareous sandstone (carbonate precipitation was not halted completely). Clastic input, volcanism, restricted basin, etc. can even change the local chemistry of the water, resulting in dramatic changes in sediments, such as phosphorites, dolomites, evaporites, etc.
Different colors are often the result of carbon content, or lack thereof, as well as sulfide content, and mineralogical content.
These sorts of depositional changes are also reflected in the amount and types of fossils present. Some organisms do well in high energy environment such as the beach (clams, burrowers, etc.), while others prefer more quiet settings. So as the depositional environments migrate back and forth along continental margins, so does animal life.
Large influxes of clastic material or significant changes in water temperature or chemistry can starve or suffocate fossil resulting is mass kill zones, which when found in the rock are termed fossil hash zones. Typically, what is seen in th rocks, are few fossils here and there, occasional fossil hash zones, rare coral reefs full of fossils, and so on. Many times, particularly in shale formations, fossils are variably replaced by iron sulfides. Shale is clay-rich and clays are particularly good at scavenging all sorts of material, such as base metals.
Sounds pretty reasonable to me when you actually understand modern geologic principles.
And that's just the sediments, all these DIFFERENT sediments, so dfiferent from each other. Different colors of limestone even. Each independently laid down in its own time period of millions of years. I find this absurd and I have not ever even seen anyone discuss it. It is merely taken for granted although it is absurd.
See above.
Besides the sediments there are the different fossil contents, each layer apparently having its own pecular content (this is what defines an era or a time period after all), that and no other. Now, this is peculiar on any theory I would think, but the idea that these were laid down one by one over millions of years also seems absurd to me. And they don't even evolve from the bottom of a layer to the top of one, they are just scattered in these layers throughout, which sure suggests a one-time event to my mind, but people seem to uncritically accept that no, each one laid itself to rest on its own particular day in all those millions of years. '
See above.
So you have an inch of I don't know, shale, and then this small fossil thing, and another inch and three fossil things, and five inches and three of the same fossil and so on. Each inch supposedly must represent the deposition of oh hundreds or thousands of years, depending on how much time the whole layer is considered to represent, and how much erosion off the top of it (only the top too, which is weird if the whole thing was abuilding over aeons) is considered to have happened.
I believe, sediment accumulation is basically controlled by the rate of basin subsidence. If the basin for some reason stops subsiding, then sediment accumulation stops and either erosion or a depositional hiatus occurs. Deposition does not HAVE to be constant and is most likely curtailed, eroded, and/or stopped many times throughout it's depositional history.
I hope this begins to convey some of my puzzlement about these phenomena which are apparently taken for granted by geologists as having happened in the above fashion which seems impossible to my mind.
Your post clearly shows that you are completely ignorant of geologic processes and principles and are thus arguing from a position of ignorance. Hopefully you are now aware of that fact and will remedy the situation post haste.
I am not trying to defend the flood at this point but it certainly does seem that a one-time event of that magnitude would do a lot better job of accounting for the actual facts than the very very slow accumulation of very small increments of sediment with dead creature after dead creature laying itself in over thousands of years apart.
See above.
This message has been edited by roxrkool, 03-07-2006 12:29 AM
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