of the North of Ireland. 17*7 



but it is said that chalk makes its appearance at Temple Patrick, 

 near the north-east angle of the lake, being there exposed by the 

 excavation of the deep valley through which the Six mile water 

 flows. 



Flcetz Trap. 



This formation in Ulster comprises the following members.* 



1. Tabular basalt, 



2. Columnar basalt, 



3. Greenstone, 



4. Greystone, 



5. Clinkstone porphyry, 



6. Bole or red ochre, 



7. "Wacke, 



8. Amygdaloidal wacke, 



9. Wood coal. 



* The sectiorv given by Dr. Richardson of the cliiFs near the Causeway well illustrates 

 the arrangement of these substances in constituting the aggregate mass of flcetz trap. 



Feet 



1. Basalt rudely columnar 60 



2. Red ochre or bole 9 



3. Basalt irregularly prismatic 60 



4. Columnar basalt 7 



3. Intermediate between bole and basalt 8 



6. Coarsely columnar basalt 10 



7. Columnar basalt, the upper range of pillars at Bengore head 54 



8. Irregularly prismatic basalt. In this bed the wacke and wood 



coal of Port Noffer are situated 54 



9. Columnar basalt, the stratum which forms the Causeway by 



its intersection with the plane of the sea 44 



10. Bole or red ochre 22 



11.^ 



12. > Tabular basalt divided by thin seams of bole 80 



13.) 



14.i 



15.> Tabular basalt occasionally containing zeolite 80 



16.) 



Vol. III. z 



