154 
LETTER FIIOM PROFESSOR ANSTED, ON GOLD IN WALES. 
To the Editor of the Geologist. 
SiE, — 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 
Cwm 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 Valley, 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, but 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 reins, 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 cf 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 quartzy lumps in slaty rocks at South Go- 
gofau, about 10 miles west of Llandovery. They also appear to have ground down 
the iron pyrites of the same district, which they afterwards washed for gold. 
