247 



been broken up into great blocks, some of which are heaved up, and 

 some let down, in the same way as at the Ballycastle colliery. In this 

 part of the coast these changes are recognisable by the white limestone 

 band and the lias, the positions of which are well known, and which 

 show as guides in this part of the inquiry. 



The Carrickmore dyke, at the Ballycastle collieries, is a feature, 

 which, though not a very prominent one, points to great physical 

 changes in the Antrim coal district. All the strata to the west of it, 

 towards Ballycastle, appear to belong to a different zone of the coal 

 measures from those on the east, towards Murlogh Bay : and which of 

 the two is the lowest and oldest is a matter not easy to decide here, 

 because the carboniferous limestone, and the old red sandstone, the 

 rocks which always accompany the coal measures, are not visible, and 

 there is no other sure guide as to succession in this district. All the 

 sandstone of the collieries already described to the west of the dyke is 

 white, or yellowish white. The sandstone to the east of it is red. This 

 red sandstone continues towards Fair Head, and is there covered by the 

 greenstone of that fine headland. Here, however, the continuity is in- 

 terrupted by the talus of debris which covers the slope from the bottom 

 of the perpendicular greenstone cliff down to the sea. The next rock 

 which appears to the east of Pair Head, under the greenstone, is black 

 shale, with thin beds of non-flaming coal. Farther south is a down- 

 throw of the coal strata, to the south, as may be seen in PI. XXYI. 



In the following Table the succession of strata, exhibited in the face 

 of the cliff, is taken in a line, sloping to the southward, but the com- 

 puted thickness of each stratum, is given at right angles to the dip.* 



Table of the Succession of the Coal Measures at Murlogh Bay, com- 



mencing at the top of the cliff. 



ft. in. 



1. Columnar greenstone, upper range at Fair Head, . 100 0 



2. Brownish red sandstone, 20 0 



3. Bituminous coal, ... . . . . 10 



4. Bed sandstone, 80 0 



5. Black shale, 6 0 



6. Coal, highly bituminous (White mine), . . .26 



7. Brownish red sandstone, . . . . . 40 0 



8. Coal, highly bituminous, ...... 0 6 



9. Bed sandstone, 0 0 



10. Black shale, 0 0 



Carried forward, . 250 0 



* This Table, as well as that at p. 244, is copied from Sir R. Griffith's Report of the 

 Antrim Coal District. I accompanied him on that survey in 1817, assisted in the mea- 

 surements of parts of it, and made the drawings that illustrate the Report. 



