The third point is the most stimulating one because the chemical
variability of mineral phases can be used to (1) discriminate
between different source rocks, and (2) to obtain more specific
information on the petrology of the source rock (Von Eynatten
and Gaupp, 1999). The main mineral phases that are common
in the studied sandstone samples and dominate in amount are:
epidote, amphibole, pyroxene, garnet, rutile and chromian
spinels. As these detrital minerals dominate the heavy mineral
assemblages in the studied area, their chemistry is of great
importance.