Stop 3 – Disaggregated gabbroc ?dyke? in migmatite.

At this locality, a fine-grained granitic phase contains grey wisps and schlieren of a slightly more mafic phase. These granitic phases appear to be transitional between leucosomes of diatexite and microgranite dykes.

Across the river and several metres downstream are rounded to sub-angular blocks of gabbro in a diatexitic host. The gabbroic unit forms a sub-linear arrangement of disrupted blocks; the angular fragments are commonly rimmed by diatexite, but show little reaction with the host. In contrast, some more rounded mafic inclusions have diffuse contacts with the leucosomes and appear to have reacted with them to form localised hybrids. The rounded mafic inclusions may have been partly molten when juxtaposed with leucosomes, whereas the blocks appear to be part of a disrupted mafic dyke that predated, or formed during the early stages of migmatisation.