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LETTER FEOM PROFESSOR ANSTED, ON GOLD IN WALES. 



To the Editor of the Geologist. 



SiR^ — One of your correspondents in the last number of your Journal 

 enquires about the gold of Wales. Perhaps a brief account of the matter 

 will be generally interesting. 



There can be little doubt that gold has been obtained in former times 

 by washing the sands of several of the rivers that come down from the 

 slate-rocks in that part of our island,^ but it was not until 1843 that the 

 Cvvm Hesian Mines near Dolgelly, in Merionethshire, were first noticed 

 by Mr. Arthur Dean, as containing something like a complete system of 

 auriferous veins. An account of this discovery was communicated at 

 the meeting of the British Association at York, in 1844. Since that 

 date the mines have been partially worked, and in 1853 I visited them 

 myself, and carefully examined the district. 



The Mowddach Yalley, and some of its small tributaries close to the 

 town of Dolgelly, contain the chief mines that have been found to pos- 

 sess any quantity of gold. The metal occurs as usual in a native 

 state, bat is found in veins and flucany cross courses, parallel and at 

 right angles to the porphyry range, which, here runs north and south 

 through Merionethshire. The nearest fossiliferous rocks are the Lingula- 

 beds of the lower Silurian series, and the veins usually occur in under- 

 lying metamorphic schists. The matrix of the veins is quartzy, and the 

 associated minerals either galena and blende, or iron and copper pyrites. 

 In addition to the gold in the veinstone, minute particles are dissemi- 

 nated through the pyrites. I noticed particularly here, and have since 

 observed elsewhere, wherever any gold was present in veins, that more 

 or less magnesian mineral (generally chlorite or steatite) is found in the 

 immediate vicinity. At the time of my visit one of the strings of gold- 

 bearing quartz in chloritic schist was opened, and I obtained from 

 a few specimens of quartz, struck off whilst I was underground, very 

 distinct threads and grains of gold ; the general yield of the small 

 quantity thus removed being at the rate of 60 ounces of gold to the ton 

 of matrix. Further researches, however, failed to discover any quantity 

 worth working, and the mine has, I believe, been since neglected. At 

 Clogau, not very far off, other auriferous specimens far richer were ob- 

 tained a year or two after my visit, but here, also, the works are stopped. 



Generally it may be said that the gold districts of Wales are limited 

 to those places where the rocks are not only schistose but chloritic or 

 steatitic. They present a very marked resemblance to those of other 

 countries where gold occurs more abundantly, but much more espe- 

 cially to those of the South-Eastern States of North America, where al- 

 most all the indications of the associated rocks and the minerals are pre- 

 cisely similar. No doubt in former times, when nearly all the rivers of 

 Western Europe brought down appreciable quantities of gold, or at 

 least when the accumulations of ages were still untouched, the Welsh 

 streams, as well as the German, French, and Spanish rivers, were rich 



The Romans obtained gold from qnartzy lumps in slaty rocks at South Go- 

 go fan, about 10 miles west of Llandovery. Tliey also appear to have ground down 

 the iron pyrites of the same district, which they afterwards washed for gold. 



