The geological elements that compose the environment of the river are various: metamorphic and carbonate rocks near the city of Ceva, the elements that belong to the Tertiary Piemonte Basin between Ceva and Alba (marine sediments) and the continental Quaternary deposits originated from the river of the southern Piedmontese plain.

The plain in the west of Alba corresponds to the alluvial plain currently crossed by the Tanaro. After the installation of the river in the current bed (Holocene), several alternating erosions and depositions have led to the formation of a sequence of deposits formed by gravels with sands, muds and clays.