This is conspicuous for biotite and amphibole crystals but less so in the strongly altered feldspar crystals.
In these first five zones, some crystals, mainly feldspars, are visible in hand specimen.
The presence of quartz-filled microcracks in feldspar crystals suggests that deformation continued during cooling and crystallization.
Such spidergrams strongly suggest that these metafelsites solidified from highly fractionated melts, which underwent extensive, low pressure, accessory phases- and feldspar-dominated crystal fractionation.
It is a medium-grained, foliated orthogneiss with small feldspar 'augen'.
Some feldspar grains, however, show weakly developed asymmetric strain shadows (-type).
The magnetic fraction of the surface sand contains pyroxene and feldspar grains as in the bulk material, but little quartz.
The two planes intersect along cd which is the locus of liquids in equilibrium with a silica polymorph + two feldspars + aqueous fluid.
