148 



differentiation from the basic rock. The rocks 

 are older than those of Sudbury, being of 

 Keewatin age. 

 224.87 m. Altitude 945 ft. (288 m.). The Porcupine 



361.7 km. branch of the Temiskaming and Northern 

 Ontario railway to the Porcupine gold field 

 leaves the main line at Iroquois Falls Junction. 

 This line passes over a drift-covered area for 

 most of the distance to Porcupine lake. South- 

 west of Iroquois there is much stratified sand 

 and gravel, while approaching Porcupine, strati- 

 fied clay is observed. Keewatin outcrops at the 

 Porcupine river crossing, and serpentine at 

 mileasre 21. 



