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Author Topic:   Radiometric Dating and the Geologic Column: A Critique
PurpleYouko
Member
Posts: 714
From: Columbia Missouri
Joined: 11-11-2004


Message 19 of 113 (166326)
12-08-2004 5:22 PM
Reply to: Message 5 by Anti-Climacus
12-08-2004 11:20 AM


Anti Climacus writes:

3) Due to the absence of governmental funding, creation scientists do not have the resources to perform such an extensive experiment.

You speak of this research as if to say it would be a big job to find 430 or so samples. Do you have any idea how many research papers are available on this subject?

I have just spent about 30 minutes searching scientific papers in my local university systems own archives. I did this all from my own office while hardly moving a muscle.

Do you know what I found?

361 abstracts directly containing "radiometric dating" in the title.
705 full papers about "Radiometric dating"
18809 abstracts with "dating" in the title. I scanned through several hundred titles and the vast majority had the words "radiometric" and "dating" in the title but not in the order defined above.
144363 papers which contain data about "dating"
2769papers directly relating to "Ar Ar dating"
203001papers that contain data on "Ar Ar dating"

I stopped searching at that point. Bear in mind that there are over 40 methods of radiometric dating and I searched for 1 and got 200,000 hits.
The only way it is going to take an inordinately long time to find the underlying correlations is if you have to sift through the massive pile of "good" data to find the one or two examples of "bad" data that even then, cannot prove the YEC position.

PY

The data is out there. Why not go get it yourself to find out how well it all corelates?


This message is a reply to:
 Message 5 by Anti-Climacus, posted 12-08-2004 11:20 AM Anti-Climacus has taken no action

  
PurpleYouko
Member
Posts: 714
From: Columbia Missouri
Joined: 11-11-2004


Message 66 of 113 (167033)
12-10-2004 5:27 PM
Reply to: Message 60 by Anti-Climacus
12-10-2004 2:36 PM


Re: An Example
Hi AC

Glad you took some advice and went out to find a real example. Hopefully we can discuss this paper in detail and this topic will remain as civil as it has so far.

I have read and re-read your critique and have also done the same for the paper that you cited.

My conclusions, however, do not match your own. To me the paper reads that the people who carried out the analysis took very great care to make sure that all of their results were "correct". Not fudged but genuinely correct.
I think some of your issues could be due to an incomplete knowledge of the processes involved in the analysis. Roxrkool explained some of it but let me give my slant on the analysis from the point of an analytical chemist. (not a geochronologist but someone who has analyzed a whole lot of rocks for chemical composition)

First I would like to say that there are parts of the paper that definitely lack adequate descriptions of methodology, particularly if you are not very familiar with analytical practices. (of course I have no idea of your own background so please excuse me if I am speaking out of line here)

I just intend to stick to my own area so let's look at the leacheates.

Leacheates are the liquid residue containing dissolved elements after a sample has been left to soak in the liquid for a period of time.


The mineral fractions were leached in warm 1N HCl for 10 minutes prior to digestion.

This is a fairly mild acid but is enough to dissolve some of the Rubidium and Sr which is easily available (not locked into crytaline structures) but doesn't come close to dissolving the locked in isotopes. That is done by the "digestion" that they mention

Why did they feel the need to leach the sample at all I wonder? It certainy isn't standard practice to soak a chunk of rock in warm acid prior to digestion. There had to be a valid pre-existing condition which they had noted in the sample in order to make it necessary.
Admittedly they didn't actually tell us the reason but if you know anything about sampling techniques then it is absolutely certain that they had one or they simply would not have done it.
It turns out that the paper does actually list this reason but you have to search a little to find it.

Rb and Sr in the host silicates may have been
fractionated and partitioned into leachable sites at ~90 Ma.

It is well known that only certain sites within the structure of the rock are leachable. Features on the rock's surface can often indicate that "shock" or some such event has occurred which would very likely have changed the chemical structure of certain parts of the rock, hence making the sites leachable.

It seems obvious to me that they must have foreseen that certain sites would be leachable or they would have had no reason to leach the rock at all. It would have been extremely bad science to have ignored this fact and carried on regardless. It should also be noted that leaching like this takes out such an infinitesimal amount of material from the parent rock that, had they not done it, the age of the bulk rock would not have changed by a measurable amount.
Therefore I would say that it speaks volumes for the integrity of these scientists that not only did they perform this "leach" but they reported it and explained it's completely predictable deviation from the primary isochron.
After all, there is a slight difference in the solubility between Rb and Sr.

I don't feel that I am qualified to comment in the defense of the actual age measurements. I am studying it in the attempt to become more familiar and knowledgable about this but (unlike chemical analysis techniques) it is still a little out of my field for now.

PY


This message is a reply to:
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PurpleYouko
Member
Posts: 714
From: Columbia Missouri
Joined: 11-11-2004


Message 72 of 113 (167089)
12-10-2004 11:26 PM
Reply to: Message 71 by Coragyps
12-10-2004 9:41 PM


Re: An Example
I think that one of the ways that they help to identify meteorites from other planets like Mars is due to their relatively young age.
Again I am no expert but I hear that most meteorites that come from ateroid collisions etc. come in at around 4.5Ga (the same age as the solar system and a little older than terrestrial rock)

Meteorites from Mars could well have been ejected from the planet as molten rock after a major impact. (speculation) This would have reset their clocks so that 170Ma would be the period since the impact.

Visible impact stress marks are probably from the meteorite hitting the Earth. Not sure how this would hold up for the martian atmosphere gas bubbles. Maybe dissolved martian atmospheric gas could have been present prior to recrystalisation.

Just a thought. Any experts out there know?

PY


This message is a reply to:
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Replies to this message:
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 Message 76 by JonF, posted 12-11-2004 11:43 AM PurpleYouko has replied

  
PurpleYouko
Member
Posts: 714
From: Columbia Missouri
Joined: 11-11-2004


Message 79 of 113 (167217)
12-11-2004 3:38 PM
Reply to: Message 76 by JonF
12-11-2004 11:43 AM


Re: Meteorite ages
Thanks for the references Jon. I will look them up when I get the chance.

PY


This message is a reply to:
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