196 THE GEOLOGICAL AGE OF CENTRAL AXD "WEST CORIfWALL. 



Near Rouitdxvood. 



Under the cliff at Victoria Point two distinct branches are 

 visible at low water, respectively 2 and 8 feet thick — with about 

 2 feet of killas between. Here there is an abrupt contortion 

 of the strata, and the dykes have been contorted with the killas 

 as shewn in fig 6. 



Fig 6. 



On Shore beloiu I 'icloria Point. 



Several small branches were formerly to be seen in the 

 quarry near Malpas, as described by Mr. Whitley many years 

 ago in the reports of the Eoyal Institution of Cornwall, but 

 they were almost entirely obliterated by an accumulation of 

 rubbish on the occasion of our last visit, in 1870. 



Nos. 23 to 25a we mark with some little hesitation as 

 belonging to this group. They are the veins numbered 40 to 

 44 by Mr. Barnett in his paper already referred to. They are 

 certainly very unlike ordinary elvans, being much browner and 

 containing much more mica. These peculiarities — a tendency 

 to spheroidal structure which is frequently observable in them — 

 their north and south course, and their nearness to undoubted 

 veins of mica-trap, induce us to believe that these also are 

 mica-traps, and to mark them as such upon the map. 



No. 26. The next appearance of this kind of rock is at a 

 point nearly 2 miles to the east of the Lamb Creek, vein No. 22. 

 It crosses the fields at the back of Nancevallan Farm, a little 

 above Penwethers, and not far from the well-known quarry on 

 the Nancevallan elvan, 



