Point load test data reveal that, in almost all 18 studied rock types,aggregate strength increases from relict to young fans. Also, the strength of aggregates in all three fans is higher at the fan apex than at the toe. The tested rocks were categorized into 5 groups. Results show that groups 2 (intrusive micaceous igneous rocks), 3 (tuffs with high porosity) and 5 (aphanitic igneous with some porosity) are sensitive to physical weathering and therefore have lower strength and quality particularly on the relict and old fans. This decrease in aggregate
strength in samples from progressively older surfaces can be explained by the duration that the fan has been exposed to weathering. Overall, it can be concluded that, apart from lithology, duration of weathering acting on the studied fans plays an important role on the quality of
aggregates.