CORNISH POST-TERTIARY GEOLOGY. 25 



(Fig. 17.) Fistral Bay. General section : 



Fig. 17. Fistral Bat. 



A. Pebbles of slate and quartz in coarse black consolidated sand. 

 BB. Boulders of quartz in the pebble bed A. 



C. Cliff section — Angular quartz stones in sand and loam, upon — 10 feet of 



sand and gravel, upon — 2 feet of gravel. 



D, Cliff section — Head — upon coarse brownish consolidated sand beds, upon 



— pebbles in black consolidated sand. 

 XX. Line of Eaised Beach, base about o feet above high-water-mark. 



The following sections have been selected out of many observa- 

 tions which I made of the cliffs in Fistral Bay. Near the centre of 

 the Bay, under Head : 



Coarse consolidated sand 



Quartz pebbles 



Coarse consolidated sand 



Sand, with numerous small pieces of slate 



Coarse consolidated sand 



Coarse black sand, with bands of gravel, of pebbles, and sub- 

 angular fragments of quartz and slate ; occasional boulders 

 near its base, which is from 5 to 6 feet above high- water mark 3ft. Oin. 



Near the north end of the bay, loam with angular slate fragments 

 rests on beds of consolidated sand, which appear to overlie —a Head 

 of angular fragments with occasional pebbles, resting on— -the Eaised 

 Beach sand and gravel. 



In this case the old blown sand seems to have accumulated upon 

 talus resting on the Eaised Beach prior to the formation of the 

 Head above. 



(Fig. 18.) At To wan Head, on the north of Fistral Bay : 

 Coarse brown consolidated sand beds, with a seaward dip of about 



15° 6ft. Oin. 



Coarse brown consolidated sand, with large angular and sub- 

 angular fragments and pebbles of quartz, slate, and granite ... 2ft. 6in. 

 Fine gravel, chiefly composed of quartz pebbles, containing large 



angular fragments of slate , 1ft. Oin. 



At base, from o to 6 feet above high-water mark. 



