U-series disequilibrium studies in the earth sciences

The nuclides of the U-series are found to separate from each other in various environmental situations although the earth as a whole remains in radioactive equilibrium. The radioactive disequilibria generated are ascribed to preferential leaching and/or recoil process and occur not only between nuclides of different elements but also between isotopes of the same element, e.g., 234U and 238U. The earth sciences utilize the disequilibria for a number of purposes including the determination of the age of certain materials such as corals, cave and spring deposits and fossil bones and teeth, the tracing of ground water flow, the determination and quantification of the subsurface mixing of ground waters, exploration for ore deposits and providing information on fluid-rock interactions