Comparing relative dating and radiometric dating
Comparing relative dating and radiometric dating - 100 dating girl from russia
Or is it more likely that they are synchronized because nothing that's happened to them has affected their working?Relative dating by definition does not produce actual dates, but it does allow us to put an order on the rocks, and so if absolute dating is to be trusted, it should agree with this order, telling us, for example, that Ordovician rocks are older than Triassic rocks; and it does.
If they don't, then it's not just a question of geologists being wrong about geology, but of physicists being wrong about physics and chemists being wrong about chemistry; if the geologists are wrong, entire laws of nature will have to be rewritten.We also see close agreement between dendrochronology and uncalibrated radiocarbon dates.(I specify uncalibrated dates because as radiocarbon dating is calibrated against dendrochronology, the agreement of calibrated radiocarbon dates with dendrochronology is inevitable.) Now, each of these three methods relies on a different underlying physical process: radioactive decay, outwash from glaciers, and the growth of trees.In Rb-Sr, Sm-Nd, Lu-Hf, Re-Os, La-Be, La-Ce and K-Ca dating, we check that the points we plot on the isochron diagram lie on a straight line.These precautions allow us to throw out most data that have been produced by confounding factors such as atmospheric contamination, weathering, hydrothermal events, metamorphism, metasomatism, etc.Throughout this process, they all go on showing exactly the same time.
Is it plausible that we have damaged their very different internal mechanisms in such a way that they are all running fast or slow but still in perfect synchrony?It is hard to see this as a coincidence; it is equally hard to think of some alternate explanation of why we can correlate isotope ratios or sclerochronological data with the relative order of rocks as deduced from stratigraphic methods — other than the straightforward explanation that absolute dating is producing the right dates.In our discussion of radiometric dating, we have seen that many, indeed most, radiometric methods are self-checking.Similar remarks may be made about the agreement between radiometric dating of rocks, sclerochronology, and dating by rhythmites.Are we to believe that one single mechanism interfered with the decay of radioactive isotopes, the secretion of calcium carbonate by molluscs, and the action of the tide? But are we instead to believe that three separate mechanisms interfered with these processes in such a way as to leave all the dates concordant? The straightforward explanation for the concordance of the dates is that they are in fact correct.Consider the following analogy: a clockmaker sells us an electric clock, a pendulum clock, and a spring-driven clock, and guarantees that they are shockproof.