uranium-series disequilibrium dating

Uranium-series disequilibrium dating is a method used to determine the age of geologically young materials. It utilizes short-lived radioactive isotopes from the uranium and thorium decay chains, which are suitable for dating recent geological samples.1

This method relies on the principle that in a closed system, radioactive elements and their decay products exist in equilibrium. However, when a uranium-bearing mineral dissolves, this equilibrium can be disrupted. For instance, uranium-234 can decay into thorium-230. In materials like old corals, the buildup of thorium-230, despite the absence of its parent uranium-234, provides a precise measure of time.1

The uranium-234 to uranium-238 dating technique is particularly useful for dating sediments from marine or playa lake environments, covering a time span from approximately 100,000 to 1,200,000 years ago. Another application is thorium-230 dating, which helps determine sedimentation rates in oceans by measuring the excess thorium-230 deposited in sediments. Additionally, lead-210 dating, derived from the uranium decay scheme, is used for dating glacial ice and recent sediments.231