ABSTRACT

Recent developments in stable isotope analytical techniques allow measuring routinely N isotopes in terrestrial samples, providing first-order observations of the behavior of N in the Earth. The results show a N-stratified Earth with an isotopic imbalance between the internal reservoirs (the mantle) and the external ones (atmosphere, biosphere and crust) which has been not yet elucidated. In this review, we show preliminary studies on the N isotopic record of Precambrian rocks and the quest of N paleocomponents (atmospheric, organic and mantle-derived) which could allow to precisely trace the geochemical evolution of this element.