Old Red Sandstone, Pease Bay, Schottland


Sedimentology as a discipline of geology is concerning all kind of rocks builded from or within sedimented materials. Lithified sediments not only include fossiles, they are archives of the era of their constitution too.

Examine fossil sediment rocks with respect to modern sedimentary environments gives us a good idea of the ancient conditions at constitution. The latter is what the geologist calls facies.