422 DEEP MINING IN NOVA SCOTIA — PREST. 



the age of a slowly deepening sea, but only a few uncertain forms 

 (probably concretions) have been found. The nature and order 

 of the deposits cf this formation are clearly shown in dif- 

 ferent parts of the province, but most completely so on Keja- 

 ma-kuja Lake and the Port Medway and Sissibou Rivers. The 

 succession of its beds is given below and a very rough estimation 

 of thickness (made in the absence of notes), accompanies it : 



1. Lower bluish-grey quartzite 6,000 



2. Bluish-grey quartzite with plumbaginous slate . .. 2,000 

 8. Upper bluish-quartzite with bluish-grey slate .... 3,000 



4. Bluish to greenish-grey quartzite and slate of 



same co'our 5,000 



5. Lower greenish-grey slate 1,000 



6. Lower purple slate < . 150 



7. Middle greenish-grey slate 1 ,500 



8. LTpper purple slate 4.00 



9. Upper greenish-grey slate 1 ,000 



10. Bluish-grey and ribbanded slates 500 



11. Bluish-black slates 2,000 



12. Black slates with white arenaceous seams 1,500 



13. Blue and bluish-grey slates 2,000 



Total about 26,000 ft. 



I may have occasion before long, from evidence lately seen, to 

 add another intercalated member to the list. 



It must be remembered that the sequence is not the same in 

 every district. In some of the eastern districts, the upper or 

 lower purple slates or both are absent. In some of the Avestern 

 districts the plumbaginous slates are absent. We can, however,, 

 be certain of one fact in this connection, viz : the order 

 is never reversed. The lowest bluish-grey quartzite is shown 

 only in our very widest anticlines, particularly at Bollard's Lake, 

 The plumbaginous slates are seen on or near the anticlinal 

 apex in many of our eastern, but not so generally in the- 

 western, districts. No. 3 is specially developed on the Sissibou ; 

 No. 4 at Mt. Thorn in Musquodoboit ; No. 5 in Queens and 



