Petrologic binary diagrams for characterizing and comparing arenites

Abstract

Point-counting according to the Gazzi-Dickinson method was performed on 136 samples of several Paleocene to Early Miocene turbidite units of the central-northern Apennines. The main components of the siliciclastic fraction are plotted on binary diagrams in which the coordinates are dimensionless ratios. The following petrographic parameters have been used: Qm/Q (monocrystalline quartz/total quartz); Q/Q + F (total quartz/total quartz + total feldspar); K/F (K-feldspar/total feldspar); Mw/M (white micas/total micas). For each pair of ratios, binary diagrams can be drawn in which each sandstone formation occupies a fairly restricted field. The simultaneous use of two or more diagrams allows two formations to be distinguished in at least one of the diagrams.