GEOL 212 Quiz: Quiz Study Guide- Radiometric dating and Stable isotope analysis
27 Dec 2017
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Several radiometric systems can be used on cais, including: the 53mn - 53cr system the measurement of the concentration of 26mg, the product of the breakdown of the short-lived 26al. Both systems indicate that cais began forming roughly two million years prior to chondrules (at roughly 4. 571 ga). But note: the uniformity of these ages implies that they formed through the same underlying process. The only reasonable hypothesis is that they condensed from the solar nebula. As nice as this sounds, we need confirmation from independent lines of evidence. Recall that a given element may have several stable isotopes (i. e. non- radoactive). Natural processes tend to sort or fractionate such isotopes in distinct ways. Consider the example of oxygen: oxygen has three natural stable isotopes, 16o, 17o, and 18o. First, a convention: rather than using absolute concentrations, it is customary to plot stable isotope ratios with respect to a standard.
