Micropaleontological counting methods and techniques : an exercise on an eight metres section of the lower Pliocene of Capo Rossello, Sicily

Abstract

The LG.C.P. project 74/1/1 "a systems approach to accuracy in time", aims
\nat a quantification of the refinement that may be attained with various
\nmethods of stratigraphic correlation.
\nA considerable part of the pilot studies carried out by the "Dutch"
\nworking group deals with the application of numerical methods in biostratigraphy,
\nin which one of the lines of research aims at a better understanding
\nof counted numbers of specimens of individual taxa in suites of samples, as
\npresented in so-called distribution charts or range charts. The biozonations
\nconstructed from such charts, from which in practice the more general zonation
\nschemes are compiled, are commonly based on entries and exits of
\nindivual taxa or groups of taxa. The corresponding datum levels based on
\nsingle or multiple presence-absence criteria (as well as relatively high frequencies
\nof taxa, so-called acmes) determine the zones recognized in the
\nvertical successions.
\nThese methods and the actual counting on which they are - often unconsciously
\n- based are being evaluated by the Utrecht team for several sections
\nof the Mediterranean Neogene.
\nThe purpose of the present investigation was only to obtain a better
\ndocumented insight in the reliability of different methods of collecting
\nquantitative data.