62 SILURIAN LIMESTONE. 



The peninsula is composed of limestone, which 

 forms low precipices at the edge of the water, as 

 well as in various places of the interior ; and the 

 same rock appears in higher cliffs on the borders 

 of the lake, about eight miles to the westward, at 

 Limestone Point. Six or seven miles back, on the 

 banks of Dease River, red sandstone is the pre- 

 vailing rock. The soil generally is a mixture of 

 gravel and loam ; and boulders of granite and trap 

 rocks are scattered over the surface of both hill 

 and valley. 



Ten miles to the eastward, a range of primitive 

 rocks rises gradually from the borders of the lake, 

 to the height of, perhaps, six hundred or seven 

 hundred feet, and separates Dease's Bay from the 

 northern arm of M'Tavish's Bay. This rising 

 ground is a continuation of the " intermediate 

 primitive belt" mentioned in p. 316, and many 

 other parts of the preceding journal, and which 

 will be described more fully in the Appendix. 

 The nearest pyrogenous or metamorphic rocks to 

 Fort Confidence that we observed are about four 

 miles off, in a bay on the south-east side of Fishery 

 Island. 



The limestone is probably the remains of the 

 silurian strata, which were removed when the 

 basin of the lake was excavated. On the south 

 side of the lake, about ninety miles distant in a 



