Z6i 



<^lomerate. This is small [)('l)l)k'd, and is probably the bed 

 forming the ledges south of the islands, although distinctly 

 smaller pebbled. South of this comglomerate there are no 

 outcrops east of Downer Avenue, 



On the west side of the avenue, we have first the con- 

 glomerate already referred to east of Whiton Avenue, fol- 

 lowed by a blank space wide enough for the sandstone north 

 of Walton's Cove ; and then we come, in the western part of 

 Melville Garden, to a broad exposure of the main conglom- 

 erate. In passing westward the strike changes gradually from 

 east- west to northwest, and there is, apparently, a marked 

 fiattening of the dip, intercalated layers of elate and sandstone 

 showing a southwesterly dip of only 5° — 10°. South of this 

 conglomerate arc ledges of sandstone followed by a blank 

 space which probably conceals the bed of purple slate already 

 noticed east of the avenue ; and then come, in the western 

 part of the garden, near Crescent Avenue, 30 feet in breadth 

 of the sandstone seen south of the purple slate, and after a 

 blank of 50 feet, 100 feet in breadth of massive gray sand- 

 stone with a southwesterly di[) of 20". Following the strike of 

 this heavy bed of sandstone east across the small pond and the 

 avenue, we have, apparently, no alternative l)ut to connect it 

 with the third or most southerly conglomerate in that part of 

 the garden. If this correlation is correct, we have here a 

 remarkable instance of rapid lateral change in the character of 

 the coarser sediments, in view of which we may well hesitate in 

 correlatinfT this section with those south and west of the 2:ranitc 

 axis. Although this explanation has the merit of simplicity, 

 and has been followed in the construction of the map, it 

 ap})ears best, on the whole, as will be more clearly shown 

 later, to introduce a third transverse or north-south fault here, 

 the fault cutting obliquely across Downer Avenue between the 

 two ponds. 



The beds of slate are commonly marked by an absence of 

 outcrops, forming smooth open lanes or narrow valleys 



