5i 



On the west side of the bay, the geology is quite different. 

 The high ridge which roughly parallels the bay consists 

 chiefly of the crystalline traps (diabase and diorite) and 

 associated clastic green schists of the Steeprock series. 

 Along the waters edge, directly west from Point No. 2, 

 is a small exposure of the volcanic ash of the same series. 



Fossilferous Limestone and Unconformable Con- 

 tact of the Steeprock Series with Laurentian at 

 Point No. 2. — At this locality, the attitude of the lime- 

 stone beds is well marked, and may be best seen in the 

 bay at the south end of the bluff. From this bay a trail 

 leads a short distance up the hill over granite, and then 

 swings northwestward across the unconformity. A con- 

 tinuous section at right angles to the contact is exposed. 

 The granite may be followed westward from a comparatively 

 unaltered phase through 45 feet (13-7 m.) of a schistose, 

 gritty, bleached variety to the Steeprock series basal 

 conglomerate. The transition is not a sharp one. The 

 conglomerate, which contains small pebbles, chiefly of 

 quartz and fine-grained granite, is from 5 to 8 inches 

 (12-7 to 20-3 cm.) thick and is followed in the direction 

 of the limestone by 50 feet (15-2 m.) of thinly bedded 

 impure, quartzitic and slaty rocks. The limestone is in 

 sharp contact with these. The nature of the uncon- 

 formity should be carefully noted in order that it may be 

 compared with that between the Laurentian and Seine 

 series to be seen on the Mine Centre trip. 



Fossils are best seen on the face of the bluff near the 

 waters edge. 



Fossiliferous Limestone at Trueman Point. — From 

 Point No. 2 the course is a direct southeasterly one up 

 the bay, with exposures of the basement complex on the 

 east and of the Steeprock series on the west. 



A ledge on the eastern side of Trueman point, near the 

 narrow rock joining it with the main shore is the locus of 

 Dr. Lawson's original discovery of fossils. Two varieties 

 are to be found. They are quite abundant near the waters 

 edge, especially along the face of the bluff. 



The contact of the limestone with the older rocks is 

 not exposed, but the fragmental formation between the 

 limestone and the granite gneiss may be seen on the side 

 of the hill just east of the southern landing. 



In places the limestone is quite sideritic, and appears 

 as a thinly-banded, brown and grey rock, resembling a 

 35069— 4A 



