Investigations on the carbonates embedded in the mainly siliciclastic post-Variscan lacustrine basins of
Sardinia have been undertaken. The features of the carbonates evolve in space and time according to peculiar times of
deposition in lacustrine environments pertaining to different morphological, tectonic and climatic context. The lacustrine
depositional environments changed in times: in Late Carboniferous-Early Permian times they were permanent lakes under
humid/temperate climate; conversely in Middle-Late(?) Permian times they were ephemeral lakes (playas) under hot/
dry climate. The carbonate intercalations, from few decimeters to some tens of meters thick, represent times of scarce or
none terrigenous input in sheltered or hypersaline areas of the lakes and show different facies arrangement according to
the evolution of the lake itself. Here we present two of the more representative examples: the Late Carboniferous-Permian
Perdasdefogu succession and the Permian Mulargia-Escalaplano succession