89 
DYKES, MINERAL VEINS, &c. 
contemporaneous origin. The latter point will attract attention, in 
another chapter, the former is totally void of evidence, and seems 
an unnecessary hypothesis, after the proof given, that the real de- 
pendence, in this region, is on the consolidation of the walls, and 
openness of the fissure. 
One peculiar geographical relation may be here mentioned, though 
it perhaps rather belongs to another chapter. Copper ores are little 
known in the limestone districts of the north of England ; except 
about Conishead Priory, in some parts of Aldstone moor, near 
Brough, and Middleton Tyas. It appears from the experience of the 
Aldstone moor mines, that copper ores rather affect the lower por- 
tions of the limestone series there, and in consequence are rather 
less rare towards the western or Penine escarpment What is known 
in Yorkshire on this subject, is of no importance; but it is remark- 
able, that there is a line of mineral deposits, passing north by 
west, parallel to the eastern range of the carboniferous deposits, 
principally yielding copper ore; in magnesian limestone at Newton 
Kyme, and Farnley, and in main limestone, at Middleton Tyas. 
N 
