Uranium-thorium decay series

Radioactive elements in rocks (see Section 2.8), most importantly potassium (K) and heavy elements such as radium (Ra), uranium (U) and thorium (Th), can release gases. Argon (Ar) arises from potassium decay and radon (Rn, a radioactive gas that has a half-life of 3.8 days) from radium decay. The uranium-thorium decay series results in the production of a particles, which are helium nuclei. Once these nuclei capture electrons, helium has effectively been added to the atmosphere. 

URANIUM-THORIUM DECAY SERIES IN THE OCEANS OVERVIEW... 

Figure 1 The natural uranium-thorium decay series, colored according to particle reactivity. The arrows represent decay with the changes in atomic number (Z) and number of nucleons (N) indicated. All three series end with a stable lead isotope.

Table 5 Summary of the processes that can be investigated using the naturai uranium-thorium decay series...

The accurate clocks provided by the uranium-thorium decay series enable us to extract rate information from the measurement of radioactive disequilibria in the ocean. Among the wide spectrum of available tracers, a mother-daughter pair with appropriate reactivities and half-lives can be found for a multitude of processes related to particle transport, water mass transport and mixing, and gas exchange (Table 5). 

River Inputs. Uranium-Thorium Decay Series in the Oceans Overview. 

Nuclear Fuel Reprocessing and Related Discharges. Single Compound Radiocarbon Measurements. Uranium-Thorium Decay Series in the Oceans Overview. 

Clay Mineralogy. Hydrothermal Vent Deposits. Platinum Group Elements and their Isotopes in the Ocean. Pore Water Chemistry. Rare Earth Elements and their Isotopes in the Ocean. River Inputs. Tracers of Ocean Productivity. Transition Metals and Heavy Metal Speciation. Uranium-Thorium Decay Series in the Oceans Overview. 

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See also in sourсe #XX -- [ ]

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