282 



PROF. J. PEESTWICH ON THE RAISED 



Mr. S. R. Pattison, on the authorit}^ of Prof. Morris, records in this 

 Beach Modiola vulgaris {Mytilus modiolus)^ Cytlierea cJiione, Osfrea, 

 and Patella.^ The thickness of the Blown Sauds or old Dunes 

 which lie between the Head and the Beach, and their marked subr 

 aerial characters, are here xery noticeable. 



Fig. 8. — Section of Cliff, Fistral Bay. 





a. Head composed of sharply angular debris of slate, with some 



large angular blocks of white quartz-rock, embedded in feet 



brown earth or loam 4 to 20 



b. Coarse greyish sand, with some seams of white quartz-pebbles, 



and some of angularfragments of slai-e 3 to 12 



c. Raised Beach : a shingle consisting chiefly of white quartz- 



pebbles, in quartzose sand, with large subangular blocks 

 of quartz. Few shells — mostly in fragments — some young 

 aheW's, oi Myatruncata{'i) 2 to 3 



I found several specimens of weathered Patella? (P. vulgata) in 

 the lower beds of sand, and Mr. Ussher mentions the occurrence of 

 " a few shells of Helix.''^ It is said that bones of Ox have also been 

 met with.^ In places the Sands are consolidated, often false- 

 bedded, and frequently contain minute fragments of the littoral 

 shells. Mr. Whitley described some circular pipes in the Sands 

 and Beach like those in Chalk districts, but at the time of my 

 visit none were visible. Mr. Pengelly has noticed similar conical 

 shafts in the old Blown Sands of Barnstaple Bay. 



Prom New Quay to the coast of Devonshire there are but few 

 traces remaining of the Raised Beach. Some unimportant portions 

 exist near St. Colomb Minor and in Constantine and Perleze 

 Bays. In Daymer Bay there is a beach-reef on the shore, which 

 Mr. Ussher says is the only example known to him in Devoii and 

 Cornwall of an old beach below high- water mark. In this are 

 fragments of slate and vegetable remains, with the roots of trees 

 (oak and hazel). The beach indicates a depression of o to 10 feet 

 below high-water mark. The exposed coast between Pentine 

 Point and Hartland Point has no Raised Beaches, but after turning 



^ Trans. Eoy. Geol. Soc. Cornwall, vol. vii. p. 50. 



- ' Report on the Geology of Cornwall, &c.,' p. 428 ; De la Beche has noticed 

 these Blown Sands in several places. 



