1854.] PATTISON AURIFEROUS QUARTZ IN CORNWALL. 247 



Whether all the reports in circulation of the occurrence of gold he 

 actually true or not, it is at all events a fact that at Dol-y-frwynog it 

 has been found in an unusual quantity, and also that its existence is 

 certain in various other places* . If in the lodes a considerable amount 

 be scattered through the country, then we should expect that gold 

 would be detected by washing the marine drift that rises on the 

 mountains of North Wales to a height of over 2000 feet. In this 

 drift it might in places be somewhat concentrated, partly by an 

 ancient natural process of sea-shore washing, partly by the more 

 modern action of rivers, as in the case of the stream-tin of Cornwall, 

 and of the gold in the superficial deposits of the Ural, of Australia, 

 of California, and in those of Canada some years ago discovered by 

 Mr. Logan. Gold, in appreciable quantities, was, indeed, found by 

 washing in the bed of the Mawddach, in the summer of 1852, by 

 the Honourable Frederick Walpole and Sir Augustus Webster (then 

 Mr. Webster). I think it probable that in this river attempts might 

 probably be most successful immediately below the confluence of 

 the Mawddach with Afon-wen, and in places in the bed of the 

 Wen, on the E. and S. water-shed of the range of hills that runs 

 from Tyn-y-Benrhos northwards towards Moel-Hafod-Owen. In 

 favourable spots it might be well worth the pains to wash the 

 detritus on the Mawddach between Dolfawr and Y-Gelli-gamlyn, and 

 in the bed of the Wen from thence to Dol-y-frwynog. This opinion 

 is founded on the fact, that the talcose rocks which the Dol-y-frwy- 

 nog lode traverses lie on the east watershed of the above-mentioned 

 range ; and, if gold be in them elsewhere in any parallel quantity 

 between Moel-Hafod-Owen and the lower part of the Llanfachreth 

 valley, then it might be expected in the detritus in the bed of the 

 stream between Dolau and Y-Gelli-gamlyn, nearly opposite to which, 

 streams that traverse the talcose rocks empty themselves into the 

 Mawddach. 



2. On Auriferous Quartz-rock in North Cornwall. By 

 S. R. Pattison, Esq., F.G.S. 



The parish of Davidstowe in the north of Cornwall is situated at 

 the edge of the granitic boss of Roughtor. Next to the granite 

 occur coarse slaty rocks, much affected by quartz-veins, and inter- 

 rupted by large developments of trap. 



By the aid of Spirifer Verneuilii in the slates at Trevivian (which 

 I found in the bed of a water-course there), and obscure traces in the 

 hmestone at Treblary, we may confidently state that these slate-rocks 

 are the prolongation of the Petherwyn beds, which, with all their 

 associates, here sweep round the northern flank of the granite. We 

 therefore characterize the district as uppermost Devonian. 



These slates are succeeded, on the east of the parish, by still 



* Since this paper was written, rich discoveries of gold have been made at 

 Clogan, on the hills north of the Dolgelli and Barmouth road. I have also seen a 

 small specimen from Penmaen, between Cwm Eisen and Trawsfynydd. [July 1854.] 

 VOL. X. part I. T 



