Preferred orientation of hornblende in a banded hornblende gneiss

Two hundred grains of a deformed hornblende gneiss from Hellandsjoeen near Trondheim, Norway, were measured, and the spatial arrangement of the hornblende grains within the rock fabric was derived by studying the distribution of the five different directions in the petrofabric diagrams. . . . It is concluded that the hornblende and biotite grains grew in preferred directions in the final phase of rock deformation and that most of therock was composed of hornblende and biotite before feldspar and quartz started to replace them.