235 



sandstone is exposed, making it probable that, as stated, tliis 

 break covers a bed of sandstone, or of sandstone and slate. 

 The sandstone forming- thi; north shore encloses from 5 to 10 

 feet of fine conglomerate, which becomes finer toward the west, 

 changing to sandstone. It encloses masses of banded slate of 

 various colors, some of which are possibly large pebbles ; but 

 the greater number, it is clear, can not be explained in that way, 

 and must be referred to the irregular deposition of fine silt with 

 the coarse. In most cases the stratification planes of the slate 

 coincide exactly with tiie bedding of the sandstone and 

 conglomerate. The correlation of the two sections is uncpies- 

 tionable ; but when we carry the line of strike from either 

 island across to the other a lateral displacement is observed, 

 each longitudinal feature on Ragged Island being about 100 

 feet farther south than its continuation on Sarah Island. This 

 want of alignment seems to be best explained by a transverse 

 fault between the two islands ; with the downtlirow to the east, 

 as shown on the map. If such a fault exists, the vertictd 

 dis[)lacen)ent must be about 75 feet. 



Some 300 or 400 feet southwest of Ragged Island, a pile of 

 angular blocks of fine conglomerate projects from the nuid flat 

 when the tide is out. These masses probably represent an 

 underlying ledge, although it is possible they were derived from 

 the Ragged Island bed. 



In the general line of strike of Ragged Island is the iiigh and 

 massive ledge of conglomerate forming the headland and tiie 

 north shore of Walton's Cove, in Melville Garden. The con- 

 glomerate has a breadth of at least 150 feet in the garden, 

 proi)ably passing beneath the water on the south ; and it may 

 be safely correlated with the main bed on the southern islands. 

 More careful observation, however, shows that there is here, 

 again, a lack of alignment, tlie southern border of the conglom- 

 erate on Ragged Island coinciding in direction very closely with 

 the northern border of the conglomerate in the garden. This 

 means a horizontal displacement of [)erhaps 150 feet, and a 



