Unitats litològiques d'interès per a la producció d'àrids a l'àrea del curs mitjà del riu Fluvià (la Garrotxa)

Pleistocene and Quaternary sediments adjacent to the medium course of the Fluvià river are a source of aggregate in the Garrotxa. Four lithological units can be used directly, or with a minimal processing as coarse aggregate. They have been mapped in detail at the 1:5.000 escale. The stratigraphic analysis have made possible the four units to be ordered in relation to their suitibility for usage as aggregate. From high to low relative quality they are: the basaltic flow, fluviatile deposits, plio-quaternary conglomerates, and glacis deposits