159 



^i'e^and^ toward the underlying Pre-Cambrian rock 

 surfaces. Just west of Willet, Mud river, 

 altitude 904 ft., (275-5 "^O has cut a channel 60 

 feet (17-8 m.) deep in stratified silt and clay. 

 [4]. 



421 m. Ferland — Altitude 970 ft. (295-8 m.) The 



673-6 km. only important rock exposure in this vicinity 



is a monadnock-like hill of Keweenawan diabase, 



known as Haystack mountain, which projects 



through the lacustrine deposits near Willet. 



ANNOTATED GUIDE— (Continued.) 



BY 



A. G. Burrows. 



Between Lake Nipigon and Iroquois Falls the 

 underlying bed rock is largely covered by glacial 

 and post-glacial deposits. The number of 

 outcrops, however, have been considerably 

 increased by excavations made during the con- 

 struction of the railways. 



The solid rocks outcropping between Lake 

 Nipigon and Iroquois Falls consist chiefly of 

 biotite and hornblende granite, granodiorite 

 and diorite. These are all more or less foliated 

 and frequently intruded by numerous dykes of 

 pegmatite and aplite. They belong to the pre- 

 Cambrian granite-diorite complex generally 

 called Laurentian. 



416 m. Pikitigushi river — Altitude 898-4 ft. 



660 km. (272-4 m.). Two miles east of the crossing 

 "*Dist.E."of Pikitigushi (Mud) river there is a N.-S. 

 215 m. trending ridge of Keweenawan diabase which 

 346 km. continues southward to form a very prominent 



peninsula on the north shore of Lake Nipigon, 



known as North Ombabika. 



* The miles and kilometres given under district-^ refer to the distance from theeasterly 

 limit of the subdivisions into which the country along the National Transcontinental 

 was divided for engineering purposes. Thus Cochrane lies 103 miles west of the eastern 

 ! mit of District D. 



