Gross composition of the Lanaittu Sandstone (Eastern Sardinia, Italy) determined by modal analysis under a polarizing optical microscope

The Lanaittu Sandstone was analyzed using the point-counting technique to determine the composition and provenance of the terrigenous detritus. 500 points were counted in each thin section, which had been stained to differentiate K-feldspar and carbonates. Analyses followed the Gazzi-Dickinson method (Ingersoll et al., 1984). Several grain categories were distinguished, including various rock fragments. The petrographic analyses were conducted in 1995 at the Geoscience Department, University of Padova, by Stefano Sanchetti, using a Zeiss optical microscope.