Talk:Isotope-ratio mass spectrometry

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Reference 14 has nothing to do with the section that cites it. Shen & You is a paper on boron isotope mass spectrometry, whereas the section discusses O18/O16 paleothermometry. A more appropriate paper to cite would be Zachos (2001) Science. —Preceding unsigned comment added by 69.107.15.164 (talk) 13:48, 8 September 2009 (UTC)

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The section on gas source mass spectrometry does not make a distinction between Peedee Belemnite and Vienna Peedee Belemnite, which I believe are two different standards. We should clarify the section as it is telling wrong information.

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Very rough start of an article--Shoka 00:13, 11 February 2006 (UTC)

Moved from the article for a more clear recasting with references to every vague statement such as "a few meters of soil shield from cosmic radiation"

Exposure and burial dating

Exposure and burial dating techniques rely on the fact that an object under a few meters of overlying material, such as soil, sediment, rock, or ice, is shielded from cosmic radiation; however, when that object is moved to the surface of the Earth it is exposed to incoming radiation. While an object is exposed to this radiation, cosmogenic nuclides such as 10Be, 14C, 26Al, and 36Cl are produced. These elements are radioactive, and have a half-life of thousands to millions of years. Measurements are typically made using an accelerator mass spectrometer, which gives a ratio of stable to radio isotopes.

Exposure dating is a technique used to find an estimated time for which an object has been on the surface of the Earth. A mass spectrometer is able to measure the ratio of these radio-isotopes to that of the stable isotope, this ratio is then used to find the absolute amount of radio-isotope in the object. The absolute amount of radio-isotope is directly proportional to the time it has spent on the surface, making it possible to find the amount of time the object has been exposed once the rate of production for a radio-isotope is known.

Burial dating, another technique involving cosmogenic nuclides, estimates the length of burial of an object. For this technique the object is assumed to have been at the surface of the Earth for some time before it becomes buried. If the amount of time an object was at the surface prior to burial is known, an initial quantity of radio-isotopes may be assumed. All radio-isotopes decay in the same fashion and the half lives of all are known, which allows the two known chemical concentrations at two different times to be placed into equations that give the length of time the object was buried. Using the chemical composition of the sample, it is possible to find the amount of radio-isotope left in the object after burial.

Jclerman 23:42, 6 July 2007 (UTC)

WikiProject class rating

This article was automatically assessed because at least one WikiProject had rated the article as stub, and the rating on other projects was brought up to Stub class. BetacommandBot 09:55, 10 November 2007 (UTC)

This article is clearly no longer a stub. Expansion of moving-wire IRMS should bring it up to B-class. Wsmitchell3 (talk) 06:29, 31 January 2009 (UTC)