168 W. A. E. Ussher — Post- Tertiary Geology of Comic all. 



large worn blocks of slaty rocks ; 3ft. 6in. tliick, and about 4 feet 

 above high water at its base. Eock platforms are noticeable at 

 about the level of spring tide high water. 





~Fig. l. — The Coast toward Rosemullion Head; showing Rock Platforms and Cliffs 

 composed of Head upon Raised Beach. 



6. South of the E. Helford. 



a. At Ligwrath, between Nare Point and Porthalla, the Head con- 

 sists of brown earth with angular stones, pebbles are met with in 

 places at its base, at about 5 feet above high water. Boulders com- 

 pose the present beach. 



b. South of the above, traces of a raised beach consisting of beds 

 of coarse black and brown sand, with grit, slate, igneous rock, and 

 small quartz pebbles, in places 2 to 3 feet thick, and at base about 

 8 feet above high water, are visible here and there under Head of 

 grey and brown loam with angular stones. 



c. Be da Beche (Eeport, p. 431) figures part of a consolidated 

 raised beach forming the roof of a cavern in the slates on which it 

 rests, and supporting a Head of angular fragments, between Port- 

 halla and the Nare Point. He also gives a sketch of the old beach 

 at Nelly's Cove and between Eosemullion Head and Mainporth (op. 

 cit. p. 432). 



d. The Eev. E. Budge (T. E. G-. S. Corn. vol. vi. p. 1) mentions 

 the occurrence of a raised beach, about 5 feet above high water, con- 

 tinuing for some hundreds of yards from Nelly's Cove (^ mile from 

 Porthalla), and accessible only at low water ; he observed traces of 

 the old beach on steep rock ledges now overflowed by the tide. On 

 the north of Nare Point, 8 to 10 feet of angular debris rested on the 

 old beach. 



7. Coverack Cove. 



a. The low cliffs to the east of Carnsullan are about 15 feet in 

 height, and composed of brown earth with angular and subangular 

 stones and boulders. 



b. The Eev. E. Budge (op. cit.) describes the cliff-section on the 

 north side of the Cove as — Bedclish-coloured marl or rubble upon a 

 thick bed (12 feet) of fine ferruginous sand, consolidated in places, 



