. Annual report . econdary quartz. Most of the feldspar showsalbite twinning lamellae. One of the thin sections examined has a fragmental appear-ance, and there is developed in and around the feldspar grains sericitic material. Felsites are also known in the underground workings of the Lawson and CrownReserve. On the 188-foot level of the former the felsite consists of plagioclase andquartz, together with calcite, chlorite and other secondary material. On the 88-footlevel of this mine similar rocks have also been met with. These felsites are probablyof intermediate composition, judging from th
. Annual report . econdary quartz. Most of the feldspar showsalbite twinning lamellae. One of the thin sections examined has a fragmental appear-ance, and there is developed in and around the feldspar grains sericitic material. Felsites are also known in the underground workings of the Lawson and CrownReserve. On the 188-foot level of the former the felsite consists of plagioclase andquartz, together with calcite, chlorite and other secondary material. On the 88-footlevel of this mine similar rocks have also been met with. These felsites are probablyof intermediate composition, judging from the presence of plagioclase and the sub-ordinate part played by quartz. On the third level of the Crown Reserve thin sections of part of the rock showedit to be a felsite, and to consist of short plagioclase rods, together with chlorite, biotiteand quartz. In the No. 5 shaft at the 130-foot level of the Drummond mine there occurs afine-grained, fresh feldspar-porphyry. It is made up of phenocrysts of an acid plagio-. Fig. 26. Part of rock surface in Fig. 25 enlarged. ? Idspar, set in a fine-grained matrix of feldspar, biotite and probably the L25 and 75-foot levels of the No. 1 shaft and on the third level of No. 3 shaftof the Hargrave similar feldspar-porphyries occur. South of Haileybury, on lot 15, in the second concession of Bucke, there is ex-! on the shore of lake Temiskaming a dike of quartz-porphyry which cuts the fine-grained greenstones. The dike is medium in grain and grey in color. The ground-insists of tiny feldspar rods and quartz, together with chlorite, which, however,subordinate. The phenocrysts consist of eyes of quartz and plagioclase feldspar,the hitter showing crystal outlines. Apparently phenocrysts of a ferro-magnesian min-eral were also once present, but they have been altered to chlorite. The acid typ< a occur in greater volume on the Quebec side of Lake Temiskaming,and are shown in the geological map prepared by .Mr. Morley E. Wilson.*
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectminesandmineralresou
