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Author | Topic: The Geologic Column | |||||||||||||||||||||||
redstang281 Inactive Member |
quote: I'm not insulting you, I'm just asking are we engaging in a search and find debate here?
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mark24 Member (Idle past 5195 days) Posts: 3857 From: UK Joined: |
quote: Pretty much, I studied radioactive decay TWICE to A level standard in chemistry & physics. The premise is pretty simple once the decay series is understood, along with half life times. All you then have to do is read up on the various methods. The question is, do you understand it? If you haven't formally studied radioactive decay (at least), then you are going to struggle a bit. Nothing wrong with that, of course. Mark ------------------Occam's razor is not for shaving with.
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Percy Member Posts: 22392 From: New Hampshire Joined: Member Rating: 5.2 |
Radiometric dating is so simple anyone can understand it. You only have to know the following, and I'm sure you already know most of it:
Now I have to take back some of my opening statement. K/Ar is the simplest of dating methods. The isochron methods are more complex, and in the last couple decades new techniques have become available that are even more complex. In geologic layers that contain materials amenable to more than one dating technique, the dates are found to agree a great preponderance of the time. --Percy
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mark24 Member (Idle past 5195 days) Posts: 3857 From: UK Joined: |
quote: A "search & find debate" is not the issue. If I have found a rebuttle to your claims then it's entirely reasonable that I post them. You need to adress what was posted, not how the information was come by. Do you understand why your original post by Snelling is incorrect? One reason that (large extrusion) basaltic sample may be suspect is that if they cool too quickly, the cooled outer surface becomes impervious to Argon, excess Argon can't ecape from the main body of lava, trapping it & giving a false measurement. In most other cases Argon involving methods work very well, thank you very much. The traditional creationist tack is to extrapolate this into meaning ALL methods are suspect, using ALL samples. Even individual bad results that don't conform, don't destroy radiometric dating as a method. If I gave you a tape measure & asked you to measure 100 things, it's entirely possible you would make an honest mistake. Does that mean that rulers are poor tools for measuring things? Of course not. I have shown four methods that all corobborate to a high degree, plus shown how they must all be innacurate to the tune of 1,000,000 % to maintain the YEC position. Do you realise how vanishingly small a chance this represents? So, what is the reason for denying radiometric methods as a whole? None, It is simply an unreasonable denial of the weight of evidence that YECs must undertake to maintain their 6,000 year old earth. Mark ------------------Occam's razor is not for shaving with.
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joz Inactive Member |
Percy,
The "is the bible the word of God" thread just reached some sort of critical mass and imploded... see the is the bible the word of God thread just threw a wobbly for mare details....
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redstang281 Inactive Member |
quote: I understand the basic idea, probably not to even the extent that you do. But it would seem to me neither of us have the real indepth understanding to debate the details of the 40ar/39ar dating. I suppose this debat is limited to search and find.
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redstang281 Inactive Member |
quote: I think I'm going to be a couple days on that thread by the time I get back to it.
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redstang281 Inactive Member |
quote: I didn't say it wasn't.
[b] [QUOTE]You need to adress what was posted, not how the information was come by.[/b][/QUOTE] That's fine too. I'll search for rebutles too.
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redstang281 Inactive Member |
quote: The the vary name of this site; "Creationist Lies and Blunders"; is Ad Hominem. He's calling creationists liars right from the beginning. His favorite target seems to be Kent Hovind. I noticed that with his alleged out of context quotes, he gives no reference to look up the use by the creationist or to original source. They are trying for a rebuttal but regardless of that; the fact is that Ar-Ar can produce ages that even evolutionists would admit are ridiculously old. The following website describes this method.
http://www.ees.nmt.edu/Geol/labs/Argon_Lab/Methods/Methods.html Note this quote:Standard Intercalibration - In order for an age to be calculated by the 40Ar/39Ar technique, the J parameter must be known. For the J to be determined, a standard of known age must be irradiated with the samples of unknown age. Because this (primary) standard ultimately cannot be determined by 40Ar/39Ar, it must be first determined by another isotopic dating method. The method most commonly used to date the primary standard is the conventional K/Ar technique. They use a sample of "know age" to find J for the samples of unknown age. The key is the fact that use K-Ar dating to determine this "known age". Why? There are plenty of lava flows around the world with real historically known ages so why not use them? The only logical reason is that the "known" must close to the expected age, based on the geologic column, so that the result is calibrated to the geologic column. http://www.ees.nmt.edu/Geol/labs/Argon_Lab/Data/Tables.html This page has a table of data from an actual sample set note that with the exception of 'A' they all have "ages" from 59-64 Ma. 'A' still has an "age" of 29 Ma. It doesn't give any information about the standard. I suspect that if historically known ages worked for a standard on all samples they would use them to give the method more credibility. Since they don't use standards of historically known age, it has probably been shown that such dates don't fit the geologic column.
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gene90 Member (Idle past 3823 days) Posts: 1610 Joined: |
[QUOTE]Origin unclear, due to Redstang's posting tactics[b]
There are plenty of lava flows around the world with real historically known ages so why not use them? The only logical reason is that the "known" must close to the expected age, based on the geologic column, so that the result is calibrated to the geologic column. [/QUOTE] [/b] quote: [QUOTE]Originally posted by Percipient[b]Since K/Ar dating is only used for material older than 50 million years, a possible residual amount of Ar-40 at levels measured by Dalrymple could cause no more than a 2 million year descrepancy, and Dalrymple's work help establish guidelines for correcting even that small error.[/QUOTE] [/b] There you have your answer, Redstang. Please read some of the posts left for you before resorting to conspiracies or asking questions that have already been answered.
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mark24 Member (Idle past 5195 days) Posts: 3857 From: UK Joined: |
quote: He is calling creationists liars, & in this case, with good reason. Here’s ONE reason. Snelling, For more than three decades potassium-argon (K-Ar) and argon-argon (Ar-Ar) dating of rocks has been crucial in underpinning the billions of years for Earth history claimed by evolutionists. Critical to these dating methods is the assumption that there was no radiogenic argon (40Ar*) in the rocks (e.g., basalt) when they formed, which is usually stated as self-evident. Dalrymple argues strongly: The K-Ar method is the only decay scheme that can be used with little or no concern for the initial presence of the daughter isotope. This is because 40Ar is an inert gas that does not combine chemically with any other element and so escapes easily from rocks when they are heated. Thus, while a rock is molten, the 40Ar formed by the decay of 40K escapes from the liquid.1 However, this dogmatic statement is inconsistent with even Dalrymple’s own work 25 years earlier on 26 historic, subaerial lava flows, 20% of which he found had non-zero concentrations of 40Ar* (or excess argon) in violation of this key assumption of the K-Ar dating method.2 Dalrymples text was from 1991, Snellings was from 1999. Snelling DELIBERATELY set out to deceive. We call it lying. Also of relevance to daughter (Ar) isotopes being present in young lava. Now let’s look at a real life example. 40Ar/39Ar Dating into the Historical Realm: Calibration Against Pliny the Younger was written by P. R. Renne et. al. and published in Science 277: 1279-1280 (1997). They tested Ar-Ar dating by checking it against the 79 A.D. eruption of Vesuvius that is famous for destroying Pompeii. Now they note that Analysis of single crystals, for example by laser fusion, can obviate xenocrystic contamination, but single crystals are seldom large enough to yield measurable quantities of 40Ar* through radiogenic ingrowth in the Holocene [i.e. last 12,000 years]. Would Ar-Ar work such recent material? It did. They got an age of 192594 years. The true age was 1918 years when the test was done. The test was off only 7 years and was correct within the margin of error. Seven years is only 0.36% of the true age. The reported margin of error for the measurement was a bit under five percent of the true age. Not bad for a method you are inferring is 1,000,000% inaccurate?
quote: Please produce some non-creationist, scientific literature that shows most Ar-Ar results show incorrect ages, because Dalrymple strongly disagrees.
quote: 39Ar (K) can only be produced by a fast neutron reaction on 39K. This means that 39Ar is a product of 39K. So, the primary standard can only be derived from a potassium source.
quote: 1/ What do you mean by standard? 2/ A 90% accuracy rate isn’t good enough for you? Now be honest, which one do you think is most likely to be in error? Nine samples are EXTREMELY close, how do you explain this? Are you seriously telling me that the method should be scrapped because 1 in 10 results didn’t conform? I’ve said this before, but if I gave you a ruler & asked you to measure the length of 10 things, & you got one wrong, would you discard rulers as being an inaccurate tool for measuring? I repeat: "So the K-T Tectites were dated by no less than four methods, that corroborate. 40Ar/39Ar, K-Ar, Rb-Sr, and U-Pb . If that weren't evidence enough, lets take a look at how innacurate they all must be, to fit a YEC world view. I'll assume, for the sake of simplicity that the K-T boundary is 60 mya, not 65 mya. Now, assuming a 6,000 year old YEC earth. This means that all the above methods, were ALL 1,000,000% innacurate. Let me reiterate, the YEC movement requires these FOUR different, corroberating methods to be ONE MILLION PERCENT INNACURATE. Thats all of them innacurate by the same amount." Can you explain the correlation? Mark ------------------Occam's razor is not for shaving with. [This message has been edited by mark24, 02-15-2002]
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redstang281 Inactive Member |
quote: One of the ironies of the evolution-creation debate is that the creationists have accepted the mistaken notion that the fossil record shows a detailed and orderly progression and they have gone to great lengths to accommodate this `fact’ in their flood geology. Raup, David M. Evolution and the fossil recordScience, Vol. 213 (July 17, 1981) p. 289
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edge Member (Idle past 1706 days) Posts: 4696 From: Colorado, USA Joined: |
quote: Excuse me, but what is your point here?
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redstang281 Inactive Member |
quote: Can you show me were they have dated strata andfound and increase in "age" with depth from the same area as an accurate dating of a historically known item?
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Percy Member Posts: 22392 From: New Hampshire Joined: Member Rating: 5.2 |
Raup is a well known mainstream paleontologist, and this quote is not something a mainstream paleontologist would say. A search of the web for this quote finds it with both more and less surrounding context, but otherwise always the same. The obvious question is one often asked: What is the point of quoting scientists appearing to say something they obviously don't believe? If scientists actually believed the things Creationists make them appear to be saying then many scientists must reject evolution. But this is simply not the case, so what sense is one to make of these quotes? I've looked up this quote, and Raup writes precisely what he is quoted as saying, but, as expected, it's been taking out of context. The quotation is from the concluding paragraph of a much longer letter. When taken all by itself, this quote appears to be conceding that the geological column does not contain a record of change over time. But in the body of the letter Raup is taking issue with the common but erroneous view that evolutionary change is one of orderly progress. He explains that this is definitely not the case, and compares it more to price fluctuations on Wall Street. So when Raup in his conclusion denies "a detailed and orderly progression" in the fossil record, he isn't saying it isn't a record of change, but merely that it isn't a record of orderly progress. Gould often says the same thing, that not only is the fossil record not one of progress, but that it isn't even possible to predict how life will respond to selection pressures. There are simply too many factors involved. Life gets bigger and smaller, obtains eyesight and loses it, obtains legs and loses them, leaves the sea and returns. This isn't an orderly progression, and that's all Raup was saying. --Percy PS - If anyone's interested in the full text of the Raup letter just let me know.
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