370 THE GEOLOGICAL HISTORY OF THE 



panying Plate VII, Fig. 1, in which the horizontal and vertical 

 distances are represented on the same scale of two inches to one 

 mile. 



The most striking feature of this section is the repetition of 

 geological formations. The red Triassic sandstone of the margin 

 of the Basin is underlaid by the shales and sandstones of the 

 Horton series, which are in turn underlaid at the summit of the 

 ridge by slates. Upon the corresponding slope on the opposite 

 side of the valley, shales and sandstones are again underlaid by 

 slates. The red sandstone is not found in the Gaspereau Valley 

 along the line of the section. 



Several interpretations of the underlying structure are 

 suggested by the surface indications. The beds are all water- 

 formed, and all dip to the northern quadrant of the compass, so 

 that the first and simplest explanation is that they form 

 successively deposited series, as shown in Fig. 2, the southern- 

 most slate older than and succeeded unconformably by the 

 southern series of sandstone and shale, this clipping beneath and 

 therefore older than the slates of the Wolfville ridge, and these 

 again unconformably overlaid by the Wolfville sandstone and 

 shale series, and these again by the calcareous red sandstones of 

 the Cornwallis Valley. 



A brief study of the rocks, however, reveals the fact that the 

 sandstone and shale formations of both slopes are alike, not only 

 in mineralogical composition but also in fossil contents, and that 

 they are merely geographically separated parts of the same for- 

 mation. If further reasons for rejecting this explanation were 

 necessary, the slates also possess similar characteristics, and we 

 know of no way in which the clay-slates of the Wolfville ridge 

 could have been cleaved and altered while the sedimentary beds 

 beneath, often as fine in texture, remained unchanged. 



A second explanation is that the rocks appearing at the sur- 

 face are the northern limbs respectively of two anticlines, as 

 shown in Fig. 3, the joining limb being concealed by the thick 

 surface deposits of the lower slopes of the north side and bottom 

 of the Gaspereau Valley. 



