366 GEOLOGY OF THE ISLE OF PURBECK. 



From this point to Gad Cliff, which, in direct 

 distance, is about six miles, the coast is much 

 indented, and is flanked by cliffs of Kimmeridge 

 clay, which are capped along the middle district 

 by Portland sand and limestone ; the total thick- 

 ness of the clays is about 300 feet. 



Rounding St. Adhelm's Head, the coast tends 

 northward, and a creek, called Chapman's Pool, 

 appears on the right ; beyond is Emmett's Hill, 

 a ridge nearly 300 feet high, capped with Portland 

 stone, resting on the Portland sands, of which a 

 good section is here exposed.* To the west, 

 the cliffs for between two and three miles are, 

 in a great measure, composed of highly bitu- 

 minous shales, and laminated clays, termed " Kim- 

 meridge coal ; " we then reach Kimmeridge Bay, 

 an excavation formed by the sea, in the low 

 tract of fissile argillaceous deposits which consti- 

 tutes this part of the coast. The view of Gad 

 Cliff from Kimmeridge Bay is very imposing, 

 for in the foreground, the black bituminous 

 clay cliffs run out into a low point, and, tower- 

 ing over them to the westward, the limestone 

 summit of the distant hill is distinctly visible. 

 The bay is partly encircled by an amphitheatre 

 of Ingh ground, the summits of which consist of 



" Sec Dr. Fitton's Memoir, p, 21 1. 



