Published online by Cambridge University Press: 01 May 2009
Near San Sebastian, northern Spain, are outcrops of a system of deep-water fans deposited beyond the mouth of a submarine canyon from southward flowing currents. The sandstones consist of mixed siliciclastic detritals and carbonate fragments. The latter includes a derived heterogeneous marine fauna. Carbonate content varies and has played a major part in diagenesis. Early cementation by limited quartz and to a greater extent calcite involved local expansion. Later compaction has led to prominent pressure-solution phenomena of calcite and quartz with formation of microstylolites. Leaching owing to weathering has led to removal of some carbonate and formation of kaolinite from micas.