. Ontario Sessional Papers, 1914, on, its full width is7,500 feet and the thickness is not less than 7,000 feet. The greywacke extends fromnear the southeastern corner of the nickel eruptive to Xaughton, a distance of 24 milesin a direction about The petrographic character of greyw^acke is somewhat vague; and the long beltof rock just outlined varies a good deal in composition, but always has some grittyparticles of quartz and feldspar in a grey ground mass of finer material. Usually therock is banded with finer and coarser layers, the bands varying from half an inch totwo or th
. Ontario Sessional Papers, 1914, on, its full width is7,500 feet and the thickness is not less than 7,000 feet. The greywacke extends fromnear the southeastern corner of the nickel eruptive to Xaughton, a distance of 24 milesin a direction about The petrographic character of greyw^acke is somewhat vague; and the long beltof rock just outlined varies a good deal in composition, but always has some grittyparticles of quartz and feldspar in a grey ground mass of finer material. Usually therock is banded with finer and coarser layers, the bands varying from half an inch totwo or three inches in thickness, probably an indication of seasonal changes. Thefiner-grained parts are slaty and usually contain pseudomorphs after staurolite, some-times small like rice grains, but occasionally reaching 5 or 6 inches in length, witha breadth of one inch. The pseudomorphs now consist of fine-grained quartz and seri-cite. In thin sections one finds in the matrix a good deal of chlorite and sericite besidecbpcure opaque Sudbur> Quartzite, with Granite to left Near Stobie there are interesting phases of the greywacke passing into coarseconglomerate in a narrow, discontinuous band not far from the base of the pebbles include granite, quartzite, greenstone and green schist. Where the greywacke lies beside later eruptives, as near Frood and Stobie, it isoften considerably metamorphosed, even passing into schist or fine-grained the southwest, as near Victoria Mine and Worthington, the greywacke propermerges into slate and also into quartzite. One band of the quartzite at Victoria minecontains 88 per cent, of silica and was mined for use as flux in the old Mond smelter. The greyw^acke has phases which connect up with arkose, slate and quartzite, andmore or less greywacke is found to the southwest of the long band just described. The Wanapitei Quartzite To the southeast of the band of greywacke there is a still wider band of quartzite,
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