The 18 rock types are lithologically common
in all six samples. For each rock type, 20 samples were taken from the
surface of fan and subjected to point load (PL) testing. The highest and
lowest values of point load test were removed from the results and
mean was then calculated for each rock type (Table 3). The PL test
values vary greatly among rock types, ranging from 0.524 (sample
6) to 8.987 (sample 13). Although data reveal that the strength values
of some rocks such as microquartz diorite (sample 16), crystalline
tuffs (sample 12) and siliceous tuffs (sample 13) are higher than other
ones, aggregates of relict, old and young fans have varying values of
strength. For all rock types, strength increases from relict to young
fans. Also, the strength of aggregates in all three types of fans is higher
in fan apex than toe.