While engaged during the past summer in carrying out some work for the Geological Survey of Canada in the eastern portion of the province of Ontario, a somewhat remarkable occurrence of orbicular or nodular granite was met in the township of Cardiff, in the county of Peterborough, which, on account of some peculiarities it presents, seemed worthy of detailed study.
This part of eastern Ontario is underlain by rocks of Laurentian age, which here consist chiefly of crystalline limestones with rusty weathering gneisses and amphibolites, broken through by great intrusions of granite, the geological relations being very complicated and intricate, as the mapping of the area now in progress shows.
About halfway across the township of Cardiff and near its southern
limits is Pine lake, a body of water some two miles long and averaging about a quarter of a mile in width. The . . .