SCIENTIFIC SURVEY. " g^g 



trials, we became discouraged, and left all the gold behind for 

 more pains-taking explorers. 



About Leadbetter falls the rock is clay slate, with the planes of 

 cleavage and stratification remarkably distinct from each other. 



Fig. 48. 



View of the strata at Leadbetter Falls. 



Pig. 48 represents the falls with the adjacent ledges of slate. 

 On the right is an island, very near the north shore, where the 

 strata dip 30° N. 30° W., but the cleavage planes dip 12° S. 30° E. 

 The strata are represented by the coarser and the cleavage planes 

 by the finer lines. Upon the south side of the river the position of 

 the cleavage planes is the same as on the island, but the strata dip 

 30° S. 30° E., forming thus an anticlinal axis. This is a very in- 

 structive example. The fall of water is too great to allow the 

 canoes to ascend the river here, hence it was necessary for us to 

 "carry by." At the further end of the portage is a large horse- 

 back, which terminates here in a ledge larger than the ridge itself. 

 We traced this horseback up the river for three miles, and found it 

 was not parallel with the course of the river. Just above Lead- 

 better falls the strata are much contorted, and appear like an 

 inverted anticlinal. The rock is more micaceous also. Still fur- 

 ther on, the dip changes to 20° S. 20° E., making a synclinal in 

 addition to the anticlinal in Fig. 48. This belt of clay slate is very 

 narrow, and is hardly to be considered as belonging to a formation 

 distinct from the mica schist on both sides of it. 



In No. 4, R. 18, are two interesting mountains, crowding closely 

 upon the river, one of which is called North Branch mountain, and 

 the other upon the east side of the river has no name. They must 

 be over 1000 feet high. The rock is a little argillaceous, but 

 largely micaceous ; being very much like the prevailing rock about 

 Bangor. About 800 feet above the river the dip is 15° N. 30° W., 

 having the same strike with the slat-es at Leadbetter falls. Near 

 the north base of the mountain is a large excavation in the strata 

 appearing very much like a quarry. The soil was probably re- 

 44 



