High Quality Content by WIKIPEDIA articles! Uranium-lead is one of the oldest and most refined of the radiometric dating schemes, with a routine age range of about 1 million years to over 4.5 billion years, and with routine precisions in the 0.1-1 percent range.The method relies on two separate decay chains, the uranium series from 238U to 206Pb, with a half-life of 4.47 billion years and the actinium series from 235U to 207Pb, with a half-life of 704 million years. These decay routes occur via a series of alpha (and beta) decays, in which 238U with daughter nuclides undergo eight total alpha and six beta decays whereas 235U with daughters only experience seven alpha and four beta decays.
Arthur Holmes (14 January 1890 20 September 1965) was a British geologist. As a child he lived in Low Fell, Gateshead and attended the Gateshead Higher Grade School (later Gateshead Grammar School). Holmes was a pioneer of geochronology, and performed the first uranium-lead radiometric dating (specifically designed to measure the age of a rock) while an undergraduate at the Royal College of Science (now Imperial College) in London, assigning an age of 370 Ma to a Devonian rock from Norway. This result was published in 1911, after his graduation in 1910. By 1911 he had already spent six months in Mozambique prospecting for minerals. While abroad he had contracted blackwater fever and malaria so severe that a note of his death was sent home by telegraph. However, he returned home and recovered though suffering life-long recurrences of the illness. 1912 saw Holmes on the staff of Imperial College, publishing his famous booklet The Age of the Earth in 1913 ( he estimated the Earth's age to be 1600 Ma). He obtained his doctorate (of Science) in 1917 and in 1920 joined an oil company in Burma as chief geologist. The company failed, and he returned to England penniless in 1924.
Radiometric dating. Isotope, Age of the Earth, Stratigraphy, Geologic time scale, Geochronology, Closure temperature, Uranium-lead dating, Potassium-argon dating, Rubidium-strontium dating, Uranium-thorium dating, Radiocarbon dating, Fission track dating, Optical dating, Isochron dating, Isotope geochemistry, Isotopic signature, Radioactive decay, Radiohalo, Sensitive high resolution ion microprobe.
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A radiogenic nuclide is a nuclide is one that is produced by a process of radioactive decay. Radiogenic nuclides (more commonly referred to as radiogenic isotopes) form some of the most important tools in geology. They are used in two principal ways: 1) In comparison with the quantity of the radioactive ''parent isotope'' in a system, the quantity of the radiogenic ''daughter product'' is used as a radiometric dating tool (e.g. uranium-lead geochronology). 2) In comparison with the quantity of a non-radiogenic isotope of the same element, the quantity of the radiogenic isotope is used as an isotopic tracer (e.g. 206Pb/204Pb). This technique is discussed in more detail under the heading isotope geochemistry.