CORNISH POST-TERTIARY GEOLOGY. 19 



varies, the upper part, for 4 feet, consisting of yellowish loam, with 

 small angular stones unequally distributed, upon — 5 feet of brown 

 loam, with small angular fragments of slate, and larger angular 

 slate, quartz, and occasionally elvan, stones. A few small flint and 

 quartz pebbles and angular stones are visible in a grey sandy top 

 soil. 



Fig. 11. Pra Sands. 

 Vertical Scale— 1 inch = 96 feet. Horizontal Scale— 5 inches = 1 mile. 



b h V 



h Blown Sand. H H Head. 



b' V Blown Sand mixing with Beach Sand obscures B Portion of a Raised Beach. 



the section. S S Killas. 



The cliffs to the west of Sydney Cove are composed of Head, 

 brown loamy clay, with angular fragments of slate and granite, 

 containing seams of brown clay with fewer stones, and passing into 

 stiff drab clay at the base of the cliff. 



Near the above the cliffs are about 50 feet in height, and com- 

 posed entirely of greyish-brown loam and clay, with angular frag- 

 ments of granite and slate. 



On a little promontory near the above, a trace of Eaised Beach is 

 visible ; it consists of 4 feet of reddish quartzose loamy sand, 

 containing pebbles, subangular slate boulders, and angular and 

 subangular fragments of quartz and slate. The base of the deposit 

 is about 5 feet above high-water mark ; it is capped by 10 feet of 

 Head, grey loam, with angular fragments. In another spot drab 

 clay overlies 2 feet of pebbles and angular and subangular fragments. 



At Trevean Cove the cliff presents the following section : 



Grey and brownish loam, containing angular stones (not of the 

 subjacent slates), occasionally presenting a stratified appear- 

 ance with a seaward inclination 8ft. 6in. 



Coarse blackish and grey sand with quartz pebbles, and sub- 

 angular fragments, also large subangular boulders of green- 

 stone, one of which measured oft. by 2ft. 6in. by 2it 4ft. Oin. 



A small piece of a broken flint pebble was obtained from this bed. 

 The base of the deposit is from 5 to 8 feet above high- water mark. 



