308 C. E. De Ranee — Mineral Veins in the NortJi-tvest Country. 



flats of lead, whicli have much in common with the great sops of 

 red ha?matite occurring in roughly N. W. and S. E. lines in the 

 Carboniferous Limestone of Furness. 



Mr. Wallace notices the fact that there are more joints in Alston 

 Moor in the limestones than in the sandstones, and more in them 

 than in the shales, and that the joints cease in depth ; this I found 

 to be the case over this area, but there are certainly as many joints 

 in the Millstone Grits east of Chorley in Lancashire (where the 

 master joint often runs parallel to a fault) as in the limestones of 

 Tynehead. His observations as to their ceasing in depth I have 

 noticed to be characteristic of joints in most formations. I had 

 opportunities of corroborating his statement that joints filled with 

 clay, often cross ' flats,' both empty, and filled with lead, and are 

 certainly of later origin than the formation and infilling of the flats. 



At Ashgill Mine both the veins and the flats contain oxide of iron, 

 so that the introduction of the iron into the lodes of this district is 

 probably of older date than the formation of the joints, the tops of 

 which are covered near the Smelt Mill with Boulder-clay, but the 

 clay found in the joints, like that in some lodes, ajopears to have been 

 derived from the decomposition of limestone shales, or of beds like 

 the pottery clay of Bel Beaver, associated with the thin coals, from 

 which clay bottles and pipes were formerly made. 



Ashgill Mine is remarkable for the lode being rich below the 

 Great Limestone, though poor in that bed, which yielded in Alston 

 Moor, according to Mr. Sopwith, F.E.S., 14,397 tons, while no other 

 bed furnished more than 500 during three years ; and which bed I 

 believe to be the same as the 12-fathom of Yorkshire described in 

 the early part of these notes. 



The Little Limestone appears to be the highest rock in which 

 zinc occurs in Alston Moor, descending to the base of the Great 

 Limestone. In the Coal Sills and Little Limestone it is associated 

 with oxide of iron, and at Guddamgill Burn this limestone is 

 turned into a carbonate of iron, which is also the case with the 

 Fell Top Limestone at Eampgill vein : much carbonate of iron is 

 present in the basalt of Tyne-bottom Mines, which I found to 

 oxidize on exposure to the air, which is again the case with strings 

 of iron in the Whin Sill of the Tees, and the siliceous lodes in the 

 Whin Sill of Tynehead. 



Sulphate of Barytes occurs plentifully in the numerous small and 

 poorly productive lodes intersecting, and often slightly faulting, the 

 westward escarpments of Cross Fell : it is here associated with 

 galena and fluor ; the latter occurs plentifully in the east and west 

 lodes, between Cross Fell and and the South Tyne, but I failed to 

 find any in the Great Sulphur Vein. 



Keviewing the evidence afforded by this district, it would appear 

 that lodes running in all directions are at times productive of iron, 

 in all limestones, from the lowest to the highest, but that the Tyne- 

 bottom, Scar and Great Limestones are the most productive. Lead 

 occurs in all the limestones, from the Melmerby Scar upwards, and in 

 many sandstones, but it is quite possible that the poorness of the lower 



