Fine sediments and clay minerals are continuously being exchanged between the inner and outer sectors of Cadiz bay, because of the influence of tidal currents. This study accounts for the analysis of embodiment and transport dynamics processes of fine sediments from continental areas and tidal flats to tidal creeks and the inner bay and from themselves to external bay and continental shelf. It has been determinated the transport path of fine sediments by means the interpretation of clay mineral associations present in sediments and the areal distribution of I/IS coefficient. Sedimentary dynamics are controlled by the contribution sediments source that directly discharge in Cadiz bay (rivers, brooks, tidal creek) and the action of superficial water currents over surface salt'marsh. Other way of fine materials embodiment are gravitational movements as: slumps and slides, occurring tidal creek and salt marsh. Exchange with external areas is made through Puntales strait by tidalj flows, as a consequence of the remobilization and resuspension of the lagoon bottom muddy sediments