Geology of the Northwest Territories province from dikes and mafic lava flows, overlain by deep ocean turbidite deposits. These rocks are believed to be the remains of oceanic crust that ended up preserved, surrounded on all sides by felsic volcanic rocks and granitoid plutons. In the area of Snofleld Lake in the northern part of the Slave Province, the remains of Archean stromatolites are preserved in a dolomite unit between felsic volcanic and greywacke-mudstone turbidites, some of the earliest evidence of life, forming in the shallows around volcanic islands. Around 1.27 billion years ago in the Proterozoic, a series of major magmatic events affected the
Charnockite thoroughly reconstituted clays and shales. It is of wide distribution and great importance in India, Ceylon, Madagascar and Africa. It was named by geologist T. H. Holland in 1893 after the tombstone of Job Charnock, in St John's Church in Calcutta, India, which is made of this rock. The charnockite series includes rocks of many different types, some being felsic and rich in quartz and microcline, others mafic and full of pyroxene and olivine, while there are also intermediate varieties corresponding mineralogically to norites, quartz-norites and diorites. A special feature, recurring in many members of the group, is the presence