PROCEEDINGS OF GEOLOGICAL SOCIETIES. 
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faults. So powerfully have these contorting forces operated, that the 
author has seen, within the distance of twenty yards, no fewer than a dozen 
foldings. A good section, showing this phenomenon, may be seen along 
the vertical coast-line around Douglas Head, for a distance of three miles. 
Again, on the opposite side of Douglas Bay, the same feature presents 
itself ; and a little further in the easterly direction, at Onchan, the rocks 
bounding its little bay are seen to form a huge anticlinal ridge, the strata 
passing over like the roof of an arch. All along this coast, as far as Eamsey, 
the same phenomenon may be studied. At times, however, great faults 
have intervened, arresting the agency which has so folded the strata, and 
turning it into another direction. Thus, on the eastern side of Greeba 
Mountain, the strata are exceedingly disturbed, great veins of white 
quartz intersecting the beds. On walking along the ridge of the moun- 
tain, and along the strike of the rocks, we perceive this folding suddenly 
to cease, and then the beds lie at a steep angle, but quite free from 
contortion. This peculiarity has been taken advantage of by Messrs. 
Ashe, and splendid slabs, tit for street pavements, etc., are now obtained 
from a quarry which they have recently opened there. Again, on a moun- 
tain opposite to Greeba, and to the east of it, at the Craig, we find the beds 
dipping at an angle of about 45° ; but these are finely-laminated blue slates, 
quite sonorous and hard, and fit for building-purposes. The masses are 
also naturally cloven into rhombic forms. Further towards Peel, there is 
a slate quarry recentl}'^ opened by the Isle of Man Slate Company, v^ here the 
strata lie at a loAver angle still, for the dip here is only about 30°; the rhombic 
cleavage still prevailing. But by far the finest section is that at Dalby, 
and seen from the coast. A fault occurs here, and, on the one hand the 
beds are in nearly a vertical position, whilst on the others are seen abut- 
ting against them. 
The colour of these beds is not persistent. Near Douglas they have a 
sort of olive-grey ; at Santon-burn they are of a claret colour ; and in the 
slate-quarries alluded to they are perfectly blue. Like many of the 
Welsh slates, the surfaces of the laniinfe are often coated with pyrites ; 
and between the chinks of the cleavage the faces of the masses are nearly 
always so coated. The degree of hardness is also variable : in some places 
they are almost as soft as common coal-shales, whilst in others sufficiently 
hard and crystalline to take a considerable polish. 
The organic remains are very scarce, and until a few years ago were 
thought to be quite absent. A friend of mine, Mr. Grindley, has, however, 
discovered a. fucoid ; and in the quarries behind Castle Mona Hotel the 
author has discovered hoih fucoids and the trades or castings of worms ; 
and in the slate-quarry of Messrs. Ashe, at Mount Craig, what he believes 
to be the section of an Orthoceratite. Near Laxey, ripple-marked slabs 
are exceedingly abundant. 
At Dalby, and very near the spot where the above-mentioned fault 
occurs, a quarry has been recently opened in the vertical strata, where 
ripple-marks are, mostly plainly, to be seen. But by far the most important 
discovery Mr. Tayh">r considers is that made by him there last summer, 
that one of the vertical faces of the rock \a as distinctly marked by impres- 
sions, each about nine inches long, and following each other at a distance 
of about two feet. He says, "The impressions were about four inches on 
each side of a straight line, and were alternately on this side and on that. 
Three such impressions were distinctly visible, and doubtless on the same 
face of the slab more would have been met with, but masses of over-lying 
rock intercepted the view. These impressions were described by me in the 
above-mentioned article in the ' Geologist.' In opposition to Mr. Salter, 
