S6 REVIEWS 



occupying most of the area north of the Ottawa River, are mapped as crystalline lime- 

 stone, gneiss, quartzite, anorthosite, granite-gneiss and porphyry. In the text the 

 limestones with the quartzites and gneisses associated with them are described as sed- 

 imentary and are classed as Grenville, and the underlying gneisses and granite-gneisses 

 are described as of igneous origin and are called Fundamental complex — in this clas- 

 sification following previous writers. It is evident that the rocks of the Grenville 

 series are decidedly newer than those of the Fundamental division. As for the numer- 

 ous and often large area of red granite gneiss, many of these are undoubtedly of 

 more recent date than either of the others since they clearly cut both the gneiss and 

 limestone. While in some points the newer granite-gneiss presents features similar to 

 the Fundamental division, as in the foliation of certain portions, there is, over large 

 areas, a marked difference in their aspect in the field. 



A. OsANN. " Notes on Certain Archsean Rocks of the Ottawa Valley." Annual 

 Report of the Geological Survey of Canada, Vol. XII (1899), New Series, 

 pp. 10-840. 



Osann makes a detailed petrographic description of the crystalline rocks in the 

 Original Laurentian area of the Ottawa Valley. 



WiLLET G. Miller. " Lake Temiscaming to the Height of Land." Report 

 of the Bureau of Mines, Ontario, 1902, pp. 214-30. 



Miller publishes geological notes taken on a canoe trip from Lake Temiscaming 

 northward to the height of land. Special attention was paid to occurrence of miner- 

 als of commercial value, and no mapping was attempted. He finds various kinds of 

 igneous rocks, both plutonic and volcanic, such as granite, syenite, diorite, olivine 

 diabase, quartz-porphyry, and others of less importance. In addition to these, most 

 of the metamorphic fragmental rocks characteristic of the Huronian occur, among 

 which may be mentioned quartzite, slate graywacke, and different varieties of the 

 pyroclastic series, ash rocks, and agglomerates. The popular belief that the height 

 of land in this district represents the highest point of the surface from which sediment 

 was derived for the formation of deposits of later age which lie to the southward 

 is scarcely based on fact. He found what appear to be thick deposits of Huronian 

 conglomerate and other water-formed material resting on the surface close to the 

 height of land. It is evident from this that the surface level must have changed con- 

 siderably since Huronian times, and that what is now the height of land may have 

 once been a comparatively low-lying area. 



L. L. Bolton. " Round Lake to Abitibi River." Report of the' Bureau of 

 Mines, Ontario, 1903, pp. 173-90. 



Bolton reports on the geological reconnaissance from Round Lake north to the 

 Abitibi River in the district of Nipissing. Laurentian granite was seen near both the 

 southeastern and southwestern corners of Eby. Elsewhere Huronian rocks are 

 exposed. Of these there is a considerable variety, many of which are of fragmental 

 origin. The following types were seen : diorite, diabase, brecciated conglomerate, 

 slate, graywacke, hornblende schist, etc. As the rock outcrops of the district explored 

 are, as a rule, separated by areas of sand, swampy, or clayey soil, the relations of the 

 different types could seldom be worked out. 



