James A. Rogers HBSc thesis abstract

Thesis Title: 
The Southeastern Margin of the Mackenzie Granite Northwestern Ontario
James A.

The Mackenzie Granite is a large granitic intrusion consisting of medium to coarse grained, pink to green granite composed primarily of oligoclase, microcline and quartz.  It is located within the Shebandowan-Wawa greenstone belt of the Superior Province where it is hosted by mafic to felsic volcanic country rocks and an amphibolite rock which may be contact metamorphic or later in origin.  The intrusion appears to be unconformably overlain to the south by Gunflint formation sediments.  The granite contains sparce xenolithic enclaves and is cut by a number of late stage dikes and later joints dikes and veins.

Detailed mapping and sampling of the granite, its immediate host rock, enclaves and dikes have been undertaken to ascertain the structure and internal fabric of the intrusion; the detailed petrology of granitic intrusive rocks, their enclaves and the possible source of such enclaves.

The instrusion contains felsci and mafic xenoliths which are representative of the contact metamorphic country rocks.  A single enclave sample of a chlorite litharenite containing oolitic fragments may represent a fragment of a Proterozoic paleosoil horizon.

The granite appears to have been intruded during the Archean Kenoran orogeny.  Structural data suggests that subsequent deformation and alteration of some areas of the granite, intrusion of later dikes and the origin of mineralized veins occurred during the Proterozoic.  Petrological evidence indicates that chloritic altearion of the granite may be genetically related to the formation of the mineralized veins.