Tertiary basins of Spain: North-western Cainozoic record: present knowledge and the correlation problem

Tertiary deposits of the north-western Iberian Peninsula are heterogeneous because they occur in several morpho-structural positions as isolated and dispersed basins and outerops. The quality of the palaeontological record is usually very poor and there are scarce data. Correlation depends on a wide range of criteria which arc not always equivalent: palaeontology, mineralogy and petrology, geomorphology, tectonics and comparison with better-known and better-dated facies in regions nearby. The results lack homogeneity and there arc notable discrepancie.