The distribution of uranium in space and time

Due to fractionation processes that have been ongoing since the inception of the Earth certain areas of the crust display anomalous concentrations and depletions of elements relative to their normal abundance levels. It is therefore of paramount importance to attempt to trace the geochemical behaviour of an element through all stages of Earth's evolution in order to identify U-enriched provinces and more importantly ore deposits within these provinces. Aspects that need to be addressed in this regard include: (1) solar abundance levels and fractionation processes during accretion; (2) changing patterns of crustal evolution and the role of irreversible differentiation, recycling and mantle metasomatism; (3) effects of an evolving atmosphere; (4) the weathering and transport cycle. Constraints on theoretical modelling of evolutionary processes have been enhanced by an improved data bank in the areas of geology, geochemistry and geophysics. In this paper an attempt is made to briefly synthesise the evolutionary development of the Earth and thereby speculate on the behaviour of uranium through time. 64 refs