The present dissertation rests on a comparative study of three sectors of the portuguese continental shelf, which were selected on the basis of the contrasting characteristics of the supplier and distributor pocesses. It aims at determining to what extent does the sediment cover reflect this contrast, at quantifying the volumes involved in the major transfer processes and at characterising the most important minerals resources.

Data from the analysis of some 900 samples were submitted to a clustering technique. The distribution of the clusters was interpreted on the basis of their characteristics and related to the major sedimentary dynamics' mechanisms which operate on the shelf, allowing the detection of some characteristics common to all sectors and of others which are only related to a given sector.

The following aspects are subsequently discussed: a) the sediment texture, grain-size and composition, with a special emphasis on the sand fraction; b) the different types of modern and relict sedimentary particles; c) the characterisation and genetic classification of the sedimentary deposits mapped in all sectors.

Several deposits, which are related with the present deposition cycle or reveal a relict character, were identified. The observations under the binocular microscope and the analysis of the supplier and distributor processes were used in order to apply a classification scheme that uses the existing relations between those processes.

Simplified sedimentary budgets were elaborated as preliminary attempts to quantify the magnitude of processes which influence material transfer, allowing the comparison of the major processes and mechanisms related with the sedimentary dynamics of each sector.

The flandrian sea-level rise is a very important forcing mechanism of the sedimentary cover distribution pattern. The obtained evidence suggest that the curve for the northern shelf can also be applied for the SW and S sectors. However, 14C dates indicate that present sea level was attained around 6,000 years BP.

The mineral resources that are more likely to be exploited in the near future are sands and gravels. The large area occupied by these deposits, as well as their characteristics and depths of occurrence, makes them a valid alternative to traditional exploitations. The economical feasibility of their exploitation is enhanced by the existence of several harbours and important rivers in the vicinity of these deposits, and of their closeness to several consumption areas.