Acta naturalia Islandica - 01.07.1964, Page 37

PLATE III
Pl. III a. Mantled olivine and
pyroxene phenocrysts in gra-
nular groundmass. The rim of
the olivine is emphasized by the
selective alternation of the
second phase of crystallization
(mantle and groundmass cryst-
als). Plane polarized light x 15.
Pl. III b. Olivine phenocryst containing granular groundmass in cavities. Plane polar-
ized light x 50.