STATHAM — OX THE GEOLOGY OF THE SCILLY ISLES. 



Lign. 1.— Secrion N. Side of Permellin 

 Bay, beneath Mount Flagon. 



composed of decayed vegetable matter, and in many places largely 

 intermixed with sand, either blown up from the adjoining beach or 

 derived from intermixture with the underlying stnitum ; 2d. A fine 

 white or ash-coloured sand, in some places, as in the pit below the 

 National Schools, containing fragments of shells ; 3d. A dai'k reddish- 

 or chocolate-brown clay, in many pai'ts of considerable thickness, and 

 having angular blocks of half-decomposed gi'anite disseminated through 

 it ; 4th. A stratum of loose gi^it, or rubbly granite, locally called " ram," 

 sometimes so comminated as to look, at a short distance off, like 

 a bed of cream-coloured limestone or sandstone, but more frequently 

 coarse, and, in the portions resting upon the granite, mingled with large 

 fi'agmentary masses of that rock. Finally, in the low and marshy 

 grounds, as at Holy Vale, and in the 

 neighbourhood of Carnfriars, traces of 

 a band of whitish pipe-clay have been 

 found, the position of which is most pro- 

 bably to be placed above the last 

 deposit, although I was not able to meet 

 with any section by which I could ascer- 

 tain its exact order. The best locality 

 for seeing at one view these various 

 beds, is a pit immediately below Mount 

 Flagon, on the bridle-path leading 

 towards Porthloo Bay. The accom- 

 panying diagram will give a fair idea 

 of it. Between 3 and -4 the road-path 

 intervenes, and Xo. 5 constitutes the 

 low cliff at this part of Permellin Bay. 

 The stratum Xo. 2 seems to take its 

 rise a little beyond Carn Morval Point, 



1 . Black surface-soil, mixed with sand 



where it can be seen capping the cliff, (is nTc- es). 

 which is there much hio-her, and run- 



F'ne ash-coloured sand (5 feet). 

 3. Reddish and Chocolate-coloured 

 clav. having large blocks of coarse 



ning along the line of the coast. No. 2 ^Tn l';^^^^^^^ ^' 



° ° • 4. Grit or coarse decomposed granite 



rubble, with large angular masses of 

 granite (20 feet). 

 5. Granite-rock. 



gi-adually thickens as it approaches St. 

 Mary's Bay, where it assumes the 

 greatest depth, exhibiting, in the neighbourhood of the National 

 School, and in a section nearly opposite the Church, sandpits of con- 



c 2 



