FAULTS. 37 



less parallel to the coast-line, which broke the 

 connection between the seaward portion and the 

 mainland ; consequently, as fast as the foundation 

 gave way, the slips followed. 



In Antrim., Ireland, along the chalk escarpment, 

 very similar slips have sometimes occurred. Open 

 joints have, at first, gradually formed in the chalk, 

 through which moisture has percolated to the under 

 beds, softening and carrying them away, till eventually 

 large masses of rock slide out into the lower country. 

 In the whole of Ulster it is hard to determine 

 whether the great slips, the remains of which are 

 apparent, are solely due to meteoric action, or 

 whether they took place when the sea washed the 

 base of the escarpment. During the present time, 

 and for ages past, such slips do not appear to have 

 taken place ; but it is quite evident that if the great 

 slips took place when the sea occupied all the low 

 country, other minor slips must have taken place 

 subsequently, probably immediately after the eleva- 

 tion of the land. 



Along these escarpments two principal systems of 

 joint-lines may be observed, one rudely parallel and 

 the other nearly perpendicular to the line of escarp- 

 merit ; and to these, in a great measure, is due the 

 different features the basset of the chalk presents. If 

 joint-lines are nearly parallel to a line of escarpment, 

 as they open the water lodges in them, and even- 



