Some samples from the amphibolite/granulite facies terrain of SW Norway show an extreme form of poikiloblastic texture: a group of at least three sections of the same mineral, generally orthopyroxene and clinoamphibole with the same optic orientation and separated by a fabric consisting of other minerals. The nucleation energy for this texture seems to be relatively high, but once a nucleus was forrned, it must have grown very rapidly. High temperature and low pressure seem to favour this extreme type of poikiloblastic texture. Similar textures are found in the contact metamorphosed Biwabik and Gunflint lron Formation of Minnesota, U.S.A.
An extreme form of poikiloblastic texture in Rogaland - Vest-Agder, SW Norway