Paint Hills Islands

Peralkaline syenites occur on two of the Paint Hills Islands in James Bay. They are in sharp contact with the surrounding volcanic rocks and outcrops are traversed by quartz veins. They are homogeneous rocks consisting of about 70% coarse, euhedral microcline perthite, 3-15% albite, 20% aegirine-augite and accessories; arfvedsonite occurred in one thin section.