A new experimental protocol for granulometric separation of calcareous nannofossils assemblages: paleoecological and geochemical applications

Calcareous nannofossils play an important role in biostratigraphy and palco ecology, though their study is often complicated by their reduced size. The methodology presented herein allows to separate the nannofossil assemblage into granulometrically and taxonomically homogeneous fractions. This metho d permits : a) the concentration of rare taxa in order to simplify their mo rphometric study; b) the geochemical analysis (stable isotopes and trace el ements) or these fractions. The latter is helpful in many cases, especially when the analysis of major or minor taxa constituent of the assemblage is greatly complicated by the reduced particles dimensions. In this way, it wi ll be possible to bring light to the ecological parameters of these taxa, a s calcification temperature and other ecological requirements (salinity, nu trient concentrations).