<p>Tongue-shaped dunes are well represented as active and old morphologies in aeolian fields of the coasts of the N Spain. Under the morphological and sedimentological point of view, grain-size parameters and mineralogical composition (carbonate vs. siliciclastic sands), two representative units are detailed: Xagó (Asturias) and El Puntal-La Salvé (eastern Cantabria). They are small elongated dunes (metric to decametric scales) whose windward side is diffuse, and the main body stretches in the direction of the wind, showing a transverse asymmetry. They acquire a lobular geometry with an almost flat crest and two unequal flanks that end up downwind on a convex migration front. Spatial variations as isoline trends in grain-size parameters: centile, mean, standard deviation, skewness and kurtosis, and biogenic carbonate percents are mapped. Crest grain sizes are finer increasing to the foot of the flanks and front, and sorting, skewness and kurtosis are variable; carbonates are low upwind and in the base of the front, increasing downwind the crets and lower flanks. The asymmetry of the dune morphology and surficial distribution of some parameters must be related to winds from the West, and later reworked by strong winds from the SW in Xagó. In the case of El Puntal-La Salvé, it can be attributed to easterly winds being reworked by northern components in El Puntal-La Salvé.</p>