### What are three types of radiometric dating

This can also disrupt the ratios of lead and uranium in the sample. Closure temperatures are so high that they are not a concern. Rubidium—strontium dating This is based on the beta decay of rubidium to strontium , with a half-life of 50 billion years. Luminescence dating Luminescence dating methods are not radiometric dating methods in that they do not rely on abundances of isotopes to calculate age. One way that a nucleus could be disrupted is by particles striking it. Modern dating methods[ edit ] Radiometric dating has been carried out since when it was invented by Ernest Rutherford as a method by which one might determine the age of the Earth. The mass spectrometer was invented in the s and began to be used in radiometric dating in the s. A famous American colleague, Professor Brew, briefly summarized a common attitude among archaeologists towards it, as follows: Uranium—thorium dating method[ edit ] Main article: Scientists have also attempted to extend the calibration range by comparing results to timber which has its age calculated by dendrochronology , but this has also been questioned because carbon dating is used to assist with working out dendrochronological ages. Isotopic systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years e. Another scientist later used other methods to derive a date of 62, years. If it does not entirely contradict them, we put it in a footnote. It is accompanied by a sister process, in which uranium decays into protactinium, which has a half-life of 32, years. This can be seen in the concordia diagram, where the samples plot along an errorchron straight line which intersects the concordia curve at the age of the sample. Hence, elements such as potassium, which has an average lifetime of nearly 2 billion years before decaying into argon, are useful for very long time scales, with geological applications such as dating ancient lava flows or Martian rocks. It is therefore essential to have as much information as possible about the material being dated and to check for possible signs of alteration. This scheme has application over a wide range of geologic dates. Uranium—lead dating method[ edit ] Main article: Key implausible assumptions There are a number of implausible assumptions involved in radiometric dating with respect to long time periods. The technique has potential applications for detailing the thermal history of a deposit. Thus an igneous or metamorphic rock or melt, which is slowly cooling, does not begin to exhibit measurable radioactive decay until it cools below the closure temperature. This predictability allows the relative abundances of related nuclides to be used as a clock to measure the time from the incorporation of the original nuclides into a material to the present. Scientists insist that Earth is 4. Accuracy levels of within twenty million years in ages of two-and-a-half billion years are achievable.