Dating techniques isotopic ratios

With respect to interpretation, the existence of alternative dating techniques has made clear the necessity for and the difficulty of this step. That is, nature seldom provides ideal dating systems with fixed injection rates, negligible losses, and constant temperature. As a result, simple dates based upon observed isotopic ratios and nuclear half-lives, for example, frequently require cautious interpretation before they can serve as accurate... 

Because of the ease of making such measurements, many descriptions of the technique have tended to emphasize its impact as a new 14C dating method. We believe that this emphasis on radiocarbon dating has been somewhat premature, as there is an enormous practical difference between the detection of 14C atoms in samples at natural concentrations using existing equipment and the measurement of 12C/13C/14C isotopic ratios with the necessary precision for dating to better than one percent accuracy. In this... 

The measurements that have been made at Rochester and the experience that has been gathered over the years on the operation of sputter ion sources [38] indicate that an analytical tool of unprecedented sensitivity and accuracy for isotopic ratio determinations can be constructed by coupling SIMS technology with the new accelerator technique. The only difference in principle between the experiments that have been conducted to date and the technique as it would be applied in secondary ion mass spectrometry is that the primary beam of cesium would be focussed to a fine probe of pm dimensions rather than the spot diameters of approximately 1 mm that have been used to date. 

During the past several years exciting advances have taken place in radioactive dating techniques—advances which have made it possible to determine unusually small isotope ratios and to determine the radioisotopic composition of individual chemical fractions and particle size fractions of extremely small samples. 

Geochronology for age dating of minerals is a major field in earth sciences, includes measurements of isotope ratios and requires advanced sensitive, precise and accurate mass spectrometric techniques. The determination of the age of the Earth has been of significant interest for hundreds... 

Artifact exportation limits, 506-507 Augustus. See Octavian Australia, Katipiri Formation, ESR dating of teeth, 3,5,61 Ayacucho, strontium isotope ratios, modem guinea pigs, 104-106 Aztec human sacrifices, sex determination by aDNA techniques, 79-80... 

In Chapter 16, Harbottle and Heino address the particular application of carbon isotopic dating to textile fibers. The discussion of the accelerator mass spectrometric (AMS) technique, which allows the accurate measurements of isotopic ratios in very small amounts of carbon, shows why this technique has had such an important impact on the field. Chapter 16 summarizes the progress in this very important methodology that remains the most accurate absolute measure of the ages of artifacts. 

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