Geology

The Ebro River Delta is the outcome of the struggle between river deposits and the action of the sea. But it hasn't always been that way. According to historical clues, during the Roman era the delta did not exist or was scarcely developed. Later, the river sediments gained ground from the sea until the delta reached its maximum size in 1957, and since then, the delta has been retreating and the sea encroaching due to the action of humans.

Given that this is a delta of a long river, the sediments are fine (silt and sand) with significant presence of organic and bioclastic matter.

In deltas, it is common to find depressed areas covered with brackish water, as in the L’Alfacada and Tancada lagoons. These lagoons are located very close to the current coastline, are not very deep and are surrounded by crop fields, wetlands and an old barrier beach with dunes.