.352 HO^'EYMAN ON KOVA SCOTIAX GEOLOGY. 



4. Black Shale 56 



5. Diorites with Pyrites and Crystals of whitish Felspar. . 16 



6. Black Slates and Shales, very pyritous, cleavage and 



jointed, having abundance of Fossils, dip 45^ 15^ 



K, 5 E 40 



7. Diorite — pyritous 24 



8. Black Slates and Shales with joints — of dip 41^ N. 



5 W 100 



9. Diorite pyritous 14 



10. Shale 140 



11. Diorite 60 



12. Shale 6 



13. Diorite 30 



14. Shale 10 



Vertical thickness of the whole 615 



It will be observed that the Lithology of this section is singular 

 from its alternation of very hard and very soft rocks. The familiar 

 diorite of the former sections occur no fewer than seven times, but 

 instead of the quartzites, granitoid rocks, porphyries, jaspideous 

 rocks and conglomerates, we have substituted very soft slates and 

 shales. The dip in the other bands described was either obscure or 

 uncertain. Here the dip of the slates and shales is unmistakable 

 and the slate beds are divided into blocks by cleavage joints, occur- 

 ing at right angles to the dip. The occurrence of Diorite, No. 7, 

 between slates 6 and 8, with so little variation of the dip together 

 with the conform ability of the other diorites, the softness of the 

 shales and other considerations to which I shall afterwards allude, 

 induce me to believe that the beds of diorite were contemporaneous 

 in formation with the slates and shales of the section. 



I would here observe in reference to thisyb7'm of diorite that I 

 have not elsewhere found it in Nova Scotia associated with uncrystal- 

 line rocks. The only other instance of its occurrence is at Arisaig, 

 in the "Lower Arisaig Series," where it is seen associated with 

 granitoid diorites, hornblende rock, limestone, ophites and ophio- 

 calcitcs. Here as in the central band of our section of the Inter- 

 colonial Railway, the crypto-crystalline passes gradually into ij^e 



