U-Th-Pb geochronology was the first and is still the fastest-growing method of measuring the rates of geologic processes through deep time and calibrating the absolute dates of events in Earth history. A variety of high U-Th minerals are found in nearly all crustal rocks, making this system the most widely applicable to understanding continental evolution. The decay of three parent isotopes to three distinct radiogenic daughter isotopes of Pb also provides a means of assessing open system behavior. This chapter describes (1) the basics of the U-Th-Pb decay chains and dating equations; (2) the different methods of visualizing U-Th-Pb data and identifying open-system behavior; (3) the various geologic processes that cause open system behavior; (4) the benefits and drawbacks of the three most popular methods of analyzing Pb/U and Pb/Th isotope ratios, namely, isotope dilution thermal ionization mass spectrometry (ID-TIMS), secondary ion mass spectrometry (SIMS), and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS); (5) the limits to precision and accuracy in U-Th-Pb geochronology; and (6) some examples of exciting current and future research directions. Though not comprehensive, this chapter is meant to be informative to both the beginners and experienced users of U-Th-Pb geochronology and provide the tools and background necessary to delve deeper into one of earth science's most exciting and rapidly evolving fields.
|Original language||English (US)|
|Title of host publication||The Crust|
|Number of pages||38|
|State||Published - Nov 2013|
All Science Journal Classification (ASJC) codes
- Earth and Planetary Sciences(all)
- Environmental Science(all)