304 C. E. De Ranee — Mineral Veins in the North-icest Country. 



traverses the country about W. and W.N.W. for a distance of nearly 

 eight miles from Hard Eigg Edge, Melmerby Fell, (where it ter- 

 minates against a S.W. fault) to the neighbourhood of Burnhope 

 Seat, on the borders of Durham, where it spreads into a number of 

 strings, which unite near Hiddenhole Mine. Following its course 

 westwards it crosses a vein which has been worked in the Sir John's 

 Mine. In the high level of this mine the miners, after penetrating 

 the Sulphur Vein, which was no less than 180 feet in width, found 

 the Sir John's vein on the opposite side, shifted 20 fathoms. This 

 high level is driven on the north side of the Sulphur Vein, in the 

 plate overlying the Scar Limestone, while on the south side it is in 

 the plate under the Cockleshell Limestone, indicating a throw of 

 more than 100 feet to the north, A little further west, the Sulphur 

 Vein is well seen on the banks of the South Tyne, just below the 

 Tynehead Smelt Mill, which is built on the Great Whin Sill, through 

 which the river has cut a narrow gorge, terminating in a waterfall 

 about 46 feet high, the base of the Whin Sill, abutting against the 

 Sulphur Vein, which on the north side throws in the Tyne-bottom 

 Limestone, which again forms the bed of the river. 



The vein is found to be mainly made up of iron pyrites in a quartz 

 matrix, with here and there large masses of the magnetic form — 

 pyrrhotine, the latter was found to contain on assay small quantities 

 of nickel and a trace of cobalt, and the former, assayed with the 

 quartz matrix, about 40 per cent, of sulphur. 



The low-level in Sir John's Mine is also driven through the 

 Sulphur Vein, which there was found to consist of enormous masses 

 of iron pyrites, with some copper. The latter mineral occurs in the 

 Sir John's and in several other veins in Tynehead in the strata 

 ranging from the top of the Scar Limestone to the top of the Tyne- 

 bottom Limestone, but more particularly in the beds known as the 

 Copper hazles, no less than 1600 tons of copper having been raised 

 from the Sir John's Vein alone since 1811. 



West of the Tyne the Sulphur Vein crosses the hill called Noon- 

 stones, where it consists entirely of pure white quartz ; descending 

 the hill, it is found in Cross Gill, where it was once, I believe, 

 worked for a short time for gold ; it consists of brown-stained 

 quartz with ordinary and magnetic iron pyrites. 



Still further west it was met with in the large mine at Smitter 

 Gill, now abandoned, where many lumps of pyrrhotine may be seen 

 lying on the refuse heaps, with fluor and other lode stuff derived 

 from the lead lode. 



Over the whole of these moors, and at the top of the ' Melmerby 

 Scar Limestone,' occur many poor lead lodes, since abandoned, 

 ranging a little north of E.N.E., nearly all of which, even in the 

 thin limestones on the escarpment under the ' Melmerby Scar,' on 

 becoming unproductive of lead, bear brown oxide of iron. The 

 increased value during the last two years has caused these lodes 

 to be actively sought for. The north and south cross veins appear 

 to be the poorest, and do not bear iron, more than lead above the 

 Great Limestone. 



