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Author | Topic: Dating by Stratigraphic Position | |||||||||||||||||||||||||||
jar Member (Idle past 425 days) Posts: 34026 From: Texas!! Joined: |
One of the oldest methods of dating things is based on where they are found in relation to other objects. In this thread I would for us to discuss the merits and limitations in positional dating.
It is hoped that those who have a position, either in support of, or attempting to refute, positional dating will participate. It is intended as a step by step analysis of positional dating where each step is fully discussed and a concensus is achieved about each step before going forward. The first issue relates to a basic assumption. Does everyone agree that if an object is found in a relative undisturbed site, that the object must be younger that what lies on top of it? {Per message 5, jar has corrected the previous paragraph to "The first issue relates to a basic assumption. Does everyone agree that if an object is found in a relative undisturbed site, that the object must be older than what lies on top of it?" - Adminnemooseus} This message has been edited by Adminnemooseus, 06-01-2004 04:10 PM Aslan is not a Tame Lion
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Adminnemooseus Administrator Posts: 3976 Joined: |
Thread moved here from the Proposed New Topics forum.
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NosyNed Member Posts: 9004 From: Canada Joined: |
The first issue relates to a basic assumption. Does everyone agree that if an object is found in a relative undisturbed site, that the object must be younger that what lies on top of it? Uh, no I don't . This isn't the best start is it? LOL
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Chiroptera Inactive Member |
Excellent topic, jar!
Of course, this is one of the methods by which Christian geologists realized that earth was hundreds of millions of years old, at least. If no true creationist decides to argue with you on this, I may try to play devil's advocate.
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jar Member (Idle past 425 days) Posts: 34026 From: Texas!! Joined: |
Ooooops is right. Mea Culpa. Thank you Ned. I can only atribute that to old age and gross stupidity.
May I revise that to say "The first issue relates to a basic assumption. Does everyone agree that if an object is found in a relative undisturbed site, that the object must be older than what lies on top of it?" Thank you sir. Aslan is not a Tame Lion
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1.61803 Member (Idle past 1535 days) Posts: 2928 From: Lone Star State USA Joined: |
The only problem I can see with dating something by position would be perhaps a shift in the strata that could possibly allow older material to surface above younger material. But I am no geologist and this is merely armchair speculation.
"One is punished most for ones virtues" Fredrick Neitzche
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jar Member (Idle past 425 days) Posts: 34026 From: Texas!! Joined: |
(surprise?) since so far we are confining this to a realtively undisturbed site.
Aslan is not a Tame Lion
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1.61803 Member (Idle past 1535 days) Posts: 2928 From: Lone Star State USA Joined: |
My bad...I thought by undisturbed you meant human..In that case I can not see a problem with the premise.
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NosyNed Member Posts: 9004 From: Canada Joined: |
So how do we distinguish an undisturbed site from others?
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mike the wiz Member Posts: 4755 From: u.k Joined: |
Simple. Rocket attends the disturbed ones, and when he isn't here, the site is undisturbed.
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Loudmouth Inactive Member |
My first question is how do we know if the sediment is undisturbed. For example, lets say that there is a limestone layer that is full of fossils. A river cuts through this limestone layer, dissolving the carbonate rock but transporting the fossil. The fossil is then deposited in the river delta and becomes part of the delta silt. With this scenario, the rock encasing the old fossil dissolves (lack of rocks in the sediment) and the fossil is older than those below it in the delta record.
PS: playing devil's advocate for a change.
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Chiroptera Inactive Member |
My guess is that there would be a lot of wear on the fossil. It is now a rock, and rocks wear a lot as they are transported. Bones are not worn, at least not like rocks. So if a fossil shows definite signs of wear, it can probably be concluded that it was transported or weathered or something after fossilization.
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jar Member (Idle past 425 days) Posts: 34026 From: Texas!! Joined: |
What about the condition of the land that surrounds the object. Does a delta or slough appear the same as the original limestone bed? Is it descrete or homogenous? Does a Delta have characteristics that we can definitely tie to specific events or cycles?
Aslan is not a Tame Lion |
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NosyNed Member Posts: 9004 From: Canada Joined: |
That doesn't sound very convincing. Why wouldn't a bone be worn? Could it wear and then fossilize?
However, let's not get stuck on the fossils. Can we get to a final point on the rock layers themselves then worry about fossils? This message has been edited by NosyNed, 06-02-2004 12:36 AM
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sidelined Member (Idle past 5939 days) Posts: 3435 From: Edmonton Alberta Canada Joined: |
loudmouth
Since it is not likely that all the fossils in a given area of limestone would all get washed into the delta it would be possible to investigate the area upriver{since I am sure the possibility of displacement by such would not escape a professional} and locate correlating fossil remains that also show limestone deposits or some other such clue.It is likely to be a mystery initially however that is the purpose of careful field work to log location and enviroment in relation to changing geology.Would this be probable? This message has been edited by sidelined, 06-02-2004 01:19 AM
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