8o 



Guide to Belfast 



several mines have been opened at Duncrue, Eden, and 

 Ballycarry, from which large quantities of rock salt have been 

 exported. The section of the Duncrue mine is as follows : 



Feet Ins. 



1. Drift 



2. Red marls with gypsum 



3. Rock Salt (ist bed) 



4. Salt and blue band ... 



5. Rock Salt (2nd bed) 



6. Blue and red band with some salt 



7. Mixed salt, blue and red band 



8. Rock Salt (3rd bed) 



9. Thin blue bands 



10. Dark-coloured rock ... 



11. Freestone 



12. Grey rock (not pierced through) 



50 



500 



15 

 6 

 88 

 17 

 13 

 39 

 6 



4 

 10 



751 7 

 At Eden the thickness of the bed of rock salt is ninety-six 

 feet; of this about fifty feet is kept intact to form the roof, 

 and the lower portion is worked, leaving large pillars to sup- 

 port the roof. Some of the beds are very pure, containing 

 from 95 to 98 per cent, of pure salt of commerce. 



The Jurassic System. 

 This system is represented in our counties by the lower 

 formations only, while the Oolites are entirely absent. Our 

 counties may claim to be unique in this respect, that it is 

 only here that the Jurassic is represented in Ireland at all. 

 As it is of interest to know what is absent as well as what is 

 present, the table subjoined will accomplish this in the most 

 comprehensive manner. 



Oolite Formations. 



[ Purbeck Beds 

 Upper or Portland Oolite - Portland Beds 



[ Kimmeridge Clay 



] Corallian \ Absent. 



( Oxfordian 



f Great Oolite Series 



( Inferior Oolite 



Middle or Oxford Oolite 



Lower or Bath Oolite 



