for the occurrence of the minerals that are so often associated with these rocks. The prevailing rocks exposed along Nelson river are biotite gneisses. Only at two places on the shores are other rocks seen, at Pipestone lake and on the southern shores of Cross lake, where a belt of Keewatin rocks crosses, and for some miles follows the river valley. The exposures at Cross lake are promising looking for the occurrence of gold, resembling closely, as they do, the gold bearing strata of the district east of Lake of the Woods. They are cut by intruded masses of the same crushed granite with blue opalescent quartz, known locally in the eastern region as Protogene.
Mr. William McInnes, in his evidence before the Senate committee of 1907, stated that in the region just west of Hudson bay there are only two or three belts of what is known as the Keewatin rocks. These are the rocks which in western Ontario hold gold. The witness found no minerals in commercial quantities. He found traces of copper on File lake. At Cross lake there is an area of these Keewatin rocks cut by intrusive granite of the same character as the protogene of western Ontario, which are almost always gold-bearing, but nothing has been found there. The limestones would make excellent building material. There are some intrusive granites on Grassy river which are of fine texture and beautiful red colour, which would make very fine monumental stone trimmings for buildings, etc., and would quarry very well. That would be along the projected line of the railway.
Nickel may be Found.
An occurrence, which seemed to Mr. McInnes to be of particular interest, was his discovery on upper Winisk river of a large area of so-called norite rock. That is the rock in which the nickel of Sudbury occurs. It is quite a characteristic rock. Mr. McInnes examined samples under the microscope, and they are not to be distinguished from the Sudbury rock. That led him to hope that there was a possibility of nickel occurring there too, but he did not find any, although he examined as well as he could. But he had not much time, and was too far away. There are two or three areas of these Keewatin rocks occurring unfolded in the Laurentian, but Mr. McInnes found no minerals in economic quantities in them at all. Near Eabamet river, a tributary of the Albany, he saw crystals of mica in the granite, two and a half inches in diameter. Of course that is not large enough to amount to much, but it shows a possibility that there might be something better there.
Mr. A. W. G. Wilson says of the district north of Lac Seul explored by him (See p. [74]):—“There seems to be little prospect of finding valuable economic minerals in the region in paying quantities. In almost all the bands of basic schists small, less often large, veins of quartz occur. At the surface these veins and the associated schists present the usual rusty appearance due to the decomposition of the pyrite. The granites are occasionally cut by pegmatitic dikes. Near the head of Cross lake, a rock, apparently of this character, carries a small amount of molybdenite in crystals varying in size up to an inch and a half across; it is uncertain whether the mineral is of economic importance, but the small size and the poor character of the specimen seen, and the difficulties of transportation point to the deposit being economically unworkable. The extent of the vein is not known. Near the inlet into Slate lake, about three-quarters of a mile from its northeast end, on the eastern shore, is the only place where magnetic minerals were found sufficiently segregated to produce a noticeable local variation of the compass. Here, stringers of a metallic mineral, probably magnetite, were found. Though this metal is sometimes a constituent of the basic rocks, the more common occurrence of iron ore is in the form of ilmenite. No hematite was noted in the district.”
In his report (See p. [60]) Mr. J. R. Dickson speaks of the mineral deposits of the area explored by his party south of Cross lake as follows:—“Judging by such necessarily superficial observations as the members of the party were able to make, the region we covered is not well supplied with economic minerals.
Traces of Copper
were found at Wekusko lake, and samples of iron ore at Sipiwesk lake, and careful prospecting might perhaps disclose deposits of commercial value, but everywhere else so far as observed, the obtruding bedrock was either pure granite or limestone. The latter, however, is mostly dolomite, the variety used as a flux in the reducing of iron ores, and future ore discoveries may give rise to such demand. This dolomite also will prove a valuable building stone for prairie towns, when made available by the Hudson Bay Railway.”
According to Mr. McLaggan (See p. [58]) the section of country about Reed lake is very rocky. Dark coloured granite, streaked with white quartz, extends along the lower end of the lake and for six miles along the river. Four miles farther Mr. McLaggan found indications of iron and saw a good water power. Above Herb lake he saw another splendid water power, very easy to develop, and along the river below rapids in five places from which fair power could be generated. At the lower end of Herb lake and along the river, granite mixed with white quartz was seen, and at the falls in the river, about twenty miles below the lake, good slate was found. On this lake Mr. McLaggan noted indications of iron. In places along and back from Grass river, on either side, quartz was seen. The country has been burned over, leaving only a few bunches of spruce, and the surface of the rock has been well exposed, so that prospecting would be easy. Mr. McLaggan thinks that this part of the country may prove rich in mineral.
On September 10, Mr. McLaggan reached Paint lake. Quartz was still in sight, but not so frequent in occurrence. There are a number of islands in the lake with rocky shores and small, mixed timber. Below Elbow lake the river banks are high, the country becomes rougher, and fire has bared the rocks of soil. White quartz crops out in considerable quantities. Along the banks of Cumberland lake there are considerable quantities of limestone, which may “become very valuable in time.”