radiometric dating

BGoodForGoodSake · Post by **BGoodForGoodSake** » Thu Dec 22, 2005 8:41 pm

Jbuza wrote:I understand where I was having problems now. I was readina site that was talking about the decay of 14c to 12c ratio. I'm up to speed on how this works.

My question is why is their 14c in Coal, natural gas, and diamonds?

There are several explanations for this but that is not the concern of this thread.

The discussion is on, Uranium-236, Technetium-99, and Plutonium-244.

The question is why do these isotopes not occur in greater quantities?

In case you did want to know, in some samples the C-14 is present in trace amounts equivalent to a biological source of aprox 50,000 years old. However the carbon from these sources are not living so such a conclusion is absurd.

Carbon retrieved from such sources are most likely contaminated as cores of diamonds and coal samples do not result in any detectable C-14.

Jbuza · Post by **Jbuza** » Thu Dec 22, 2005 8:59 pm

Jbuza · Post by **Jbuza** » Thu Dec 22, 2005 9:02 pm

IT appears that all coal still contains 14c. SO it doesn't appear to be a contamination issue, but a problem with the geological time scale

BGoodForGoodSake · Post by **BGoodForGoodSake** » Thu Dec 22, 2005 9:06 pm

Jbuza wrote:I thought it was to discuss issues with radiometric dating. So did you decide wether those elements are here by natural or supernatural means yet?

I will reiterate again, natural means yes, occuring naturally no.

BGoodForGoodSake · Post by **BGoodForGoodSake** » Thu Dec 22, 2005 9:07 pm

Jbuza wrote:IT appears that all coal still contains 14c. SO it doesn't appear to be a contamination issue, but a problem with the geological time scale

Lets ignore C-14 for the time being seeing as you have already made up your mind using your favorite sources to reinforce those beleifs.

Can we move on with the topic at hand?

Jbuza · Post by **Jbuza** » Thu Dec 22, 2005 9:10 pm

Yehren · Post by **Yehren** » Thu Dec 22, 2005 9:36 pm

Recently, radiometric testing was verified in a brand new way.

The volcanic flows that covered Pompeii were dated using argon/argon methods.

And it worked. Very accurate, even with extremely young deposits.

A powerful geologic dating technique called argon-argon dating has pegged the 79 A.D. eruption of Vesuvius so precisely that it establishes one of the most solid and reliable anchors for any dating method.
http://www.berkeley.edu/news/media/rele ... mpeii.html

sandy_mcd · Post by **sandy_mcd** » Thu Dec 22, 2005 11:42 pm

Jbuza wrote:http://www.freerepublic.com/focus/f-blo ... 8154/posts

It's really striking how a relatively simple topic like this can give rise to such opposed viewpoints. I read the post referenced and many of the comments. Here is a different viewpoint (abstract only, see link, if it works, for full article) which I found while looking up diamonds and 14C.

http://nvl.nist.gov/pub/nistpubs/jres/109/2/j92cur.pdf

Title: The remarkable metrological history of radiocarbon dating [II]
Author(s): Currie LA
Source: JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY 109 (2): 185-217 MAR-APR 2004
Document Type: Review
Language: English
Cited References: 76 Times Cited: 1 Find Related Records Information
Abstract: This article traces the metrological history of radiocarbon, from the initial breakthrough devised by Libby, to minor (evolutionary) and major (revolutionary) advances that have brought C-14 measurement from a crude, bulk [8 g carbon] dating tool, to a refined probe for dating tiny amounts of precious artifacts, and for "molecular dating" at the 10 mug g to 100 mug level. The metrological advances led to opportunities and surprises, such as the non-monotonic dendrochronological calibration curve and the "bomb effect," that gave rise to new multidisciplinary areas of application, ranging from archaeology and anthropology to cosmic ray physics to oceanography to apportionment of anthropogenic pollutants to the reconstruction of environmental history.

Beyond the specific topic of natural C-14, it is hoped that this account may serve as a metaphor for young scientists, illustrating that just when a scientific discipline may appear to be approaching maturity, unanticipated metrological advances in their own chosen fields, and unanticipated anthropogenic or natural chemical events in the environment, can spawn new areas of research having exciting theoretical and practical implications.
Author Keywords: accelerator mass spectrometry; apportionment of fossil and biomass carbon; "bomb" C-14 as a global tracer; dual isotopic authentication; metrological history; molecular dating; radiocarbon dating; the Turin Shroud; SRM 1649a
KeyWords Plus: ACCELERATOR MASS-SPECTROMETRY; CARBON; C-14; AEROSOLS; URBAN; DISTRIBUTIONS; HYDROCARBONS; ATMOSPHERE; COMBUSTION; PARTICLES
Addresses: Currie LA (reprint author), NIST, Gaithersburg, MD 20899 USA
NIST, Gaithersburg, MD 20899 USA
E-mail Addresses: (deleted)
Publisher: US GOVERNMENT PRINTING OFFICE, SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA
Subject Category: ENGINEERING, MULTIDISCIPLINARY; MULTIDISCIPLINARY SCIENCES
IDS Number: 846WS
ISSN: 1044-677X

Jbuza · Post by **Jbuza** » Fri Dec 23, 2005 1:42 am

Jbuza · Post by **Jbuza** » Fri Dec 23, 2005 1:51 am

Yehren · Post by **Yehren** » Fri Dec 23, 2005 7:14 am

According to the assumptions foundational to potassium-argon (K-Ar) and argon-argon (Ar-Ar) dating of rocks, there should not be any daughter radiogenic argon (40Ar*) in rocks when they form.

Right. When rock is liquified, the clock is reset, because it's offgassed. This is why even very recent flows, like that at Pompeii, could be accurately dated by the method.

When measured, all 40Ar* in a rock is assumed to have been produced by in situ radioactive decay of 40K within the rock since it formed. However, it is well established that volcanic rocks (e.g. basalt) contain excess 40Ar*, that is, 40Ar which cannot be attributed to either atmospheric contamination or in situ radioactive decay of 40K

Many such rocks do. This is why you can't just grab a chunk of rock and test it, without knowing what it is. The rocks at Mt. St. Helens, for example, contain unmelted xenocrysts, which not having melted, will give a very ancient date to the rock, unless the xencrysts are laboriously removed. This is the method Austin used in his hoax involving the age of rock on Mt. St. Helens. The lab he used specifically warned him about the problems, but he insisted on "analyzing" his samples anyway, and was then shocked to learn that the results were not good.

There are entire books on the precautions one must take in order to accurately date rocks. Anyone who ignores them can easily get misleading dates.

However, all of that is moot to the point; if it didn't work, it wouldn't have worked for the Pompeii rocks.

Reality trumps anyone's reasoning.

Jbuza · Post by **Jbuza** » Fri Dec 23, 2005 9:03 am

Yehren · Post by **Yehren** » Fri Dec 23, 2005 9:31 am

ARgon-Argon yields correct dates.

Yep. Directly calibrated with a known date.

ARgon-Argon yields incorrect dates.

When improperly used, and only then.

Argon-Argon isn't reliable.

No method is reliable when used improperly. But as you learned, it is both reliable and accurate.

IT is not known what amount of 40A is naturally occouring outside of its prescense as a daughter product of 40K. 40A makes up over 99% of argon.

Doesn't matter. Isochrons make such assumptions unnecessary.

Here's a place to learn about it:

http://vcourseware5.calstatela.edu/VirtualDating/

Reality trumps anyone's reasoning.

Jbuza · Post by **Jbuza** » Fri Dec 23, 2005 9:46 am