GRINDLEY — GEOLOGY OF THE ISLE OF MAN. 
175 
by practical men would be rewarded bv the discovery of gold in re- 
munerative quantities. Garnets, of a small size, are found at Greeba. 
Kesting upon the upturned edges of the older schists are found, on 
both sides of the island, some very interesting deposits of the Devo- 
nian period. Of the intervening Silurian beds but few traces now 
remain among the Manx rocks. Of their former existence, however, 
we have satisfactory proof in the fact that water-worn pebbles of 
Silurian age, containing characteristic fossils, enter largely into the 
composition of the overlying Old Eed, particulnrly near Peel. The 
Devonian rocks lie unconformably upon the underlying Cambrian 
schists. At Langness, where this uuconformability of the two series 
of rocks is beautifully exhibited, while their strike is almost identical, 
their dip is opposed — the schists dipping S.E. at a high angle, and 
the overlying Old Eed dipping jST.W. at an angle, in this place, 
almost equally high. They attain their greatest development to the 
north of the central ridge near Peel, being there several hundred feet 
thick, — principally of a workable sandstone. The venerable castle 
and a great part of the town of Peel are built of it ; but it forms a 
very indifferent building material, being very soft, and decomposing 
rapidly by the action of the atmosphere. It is in the southern basin, 
however, near the ruins of Eushen Abbey, and along the west coast 
of Langness, that the rocks of this formation present their most in- 
teresting features, and where their relations to the underlying schists 
and the overlying limestone can be best observed. Proceeding along 
tlie western shore of Langness, the schists, here of a deep claret 
colour, are seen underlying the Old Eed, and dipping inland (S.E.) 
at a high angle, much contorted; while the Old Eed itself dips sea- 
ward (N.W.) at an angle equally high. The junction of the Old Eed 
with the overlying limestone is not well developed in this locality, still 
by a little careful management it may be traced in the north-eastern 
corner of the bay, and the direction and intensity of their dip may 
be seen to be identical. The Old Eed, as developed in this locality, 
is a coarse conglomerate of quartz and other pebbles, many of them 
of considerable size, enclosed in a red clayey matrix. It attains a 
considerable thickness, but, so far as my own observations extend, 
contains no fossils. It is possibly the equivalent of the conglomerate 
beds of the typical " Old Eed" of Herefordshire, etc. 
Further inland, near the ruins of Eushen Abbey, founded in 1134? 
by the Cistercian monks of Furness, we may trace the passage of the 
Devonian beds into the overlying Carboniferous limestone with 
greater accuracy. The conglomerate has here lost its characteristic 
red colour, and appears as a thin bed of very small white quartz 
pebbles in a limy matrix, enclosing the characteristic fossils, princi- 
pally Ortliis SJiarpei, of the lowest Carboniferons rocks. About a 
mile higher up the Silverburn, near Athol Bridge, the passage of this 
grey conglomerate into the dark limestones and shales of the lower 
Carboniferous beds may be distinctly traced. The same appearances 
are also very clearly seen in ascending the Brough, a low hill over- 
looking the romantic valley of the Santonsburn, about two miles 
