Clay minerals from the sedimentary cover from the Northwest Iberian shelf

摘要: Abstract The Northern Iberian margin is a typical example of continental subjected to seasonal highly energetic regime (waves and tides) receiving inputs sediments via riverine discharges. principal goal this study has been use clay minerals as indicators sedimentary dynamics in the open shelf system. distributions mineral top layer cover are shown be related their sources, but also reflect influences winter storms longshore currents determining pathways sediment transport. mineralogical composition material issuing from rivers very similar general fine fractions seabed sediments. Those deposits that directly influenced by discharges have higher contents kaolinite (>20%), whereas those not illite (>80%). available data indicate no significant quantities terrigenous particles being discharged Spanish rias. Therefore, we conclude physical processes controlling that, despite contributions Minho River, main source detrital region Douro River discharge. These settle on middle shelf, below 60 m isobath. During storm events these re-suspended advected northwards Galician or into deeper domains. Thus clays there net transport both off-shelf.