310 ON THE GEOLOGICAL FEATURES OF EDMONBYERS. 
XL.—On the Geological Features of the Parish of Edmondbyers. 
By the Rev. W. Fraturrstonnaucn, M.A. 
Tue Parish of Edmondbyers, for five miles, forms the 
north west boundary of the County of Durham, and is mostly | 
unenclosed moorland. The higher ranges of hills, varying from 
1,000 to 1,300 feet above the level of the sea, are composed of 
beds of sandstone, of various qualities, and form, I believe, a 
part of the “‘ Millstone grit” of geologists, the strata of which 
dip towards the south east, and overlie, in downward order respec- 
tively, beds of iron-stone, lime-stone, (both the thin stratum called 
‘fell-top-limestone,” and the massive Stanhope beds,) and again 
the metalliferous strata which furnish the mineral wealth of the 
Derwent Heads and Allenheads lead mines. 
The sandstone beds are found to consist of three separate and 
quite distinct varieties. The lowest is a coarse, quartzose, 
durable sandstone, imperishable as a building stone; of which 
detached masses lie scattered over the surface of the moor, either 
in separate blocks, or in congregated heaps, the former burden of 
some grounded glacier, or covering the shelving beach of an 
ancient sea, which, by the continued beating of its angry surf, 
has detached them from the disjointed and ragged face of the 
cliff exposed above. The next variety of sandstone, upwards, is 
a compact, fine-grained, massive freestone, valuable for all finer 
building purposes, from the purity of its colour, its freedom from 
chemical elements injurious to permanency, its excellent working 
qualities under the chisel, and the size and uniformity of the 
blocks which it furnishes. The upper portion of these beds con- 
sists of laminated micaceous sandstone, producing the thin grey 
roofing slate adopted in the district, flagstones of durable quality, 
and thicker parallel-jointed stones, as convenient as bricks in 
building walls. 
The above are the chief varicties of sandstone existing in these 
beds; but the most noticeable feature is the occurrence of detached 
volcanic masses, doubtless referable to the period when the 
underlying beds were torn by convulsive throes, and the fissures 
injected with molten metal, forming veins and strings of ore. It 
