Part IIMetamorphism of Specific

Rock Types

Garnet-granulite (coronite) from Ytre Arna, Bergen Arcs,Norway. Matrix of rock: plagioclase (white), clinopyroxene(green), garnet (brown). Protolith: Igneous olivine – plagioclaserock (troctolite). Sites of coarse igneous olivine transformed toconcentric structures (corona structures) with orthopyroxenecores, dark clinopyroxene and brown rims (coronas) of garnet.The texture resulted from the reaction of olivine with plagioclaseat pressures of the lower continental crust. Reaction products areCpx þ Grt. The texture also shows that metamorphic reactionsoften involve small-scale transport processes