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 few er than a do/en 

 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 Kamsey, 

 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 recently opened by the Isle of Man Slate Company, where the 

 strata lie at a lower 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 arc 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 lamina) 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, w hilst in others sullieiently 

 bard 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 afucoid ; and in the quarries behind Castle Mona Hotel the 

 author has discovered both fucoids and the tracks 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 

 arc 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. Taylor considers is that made by him there last suinnu r. 

 that one of the vertical faces of the rock was 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 w ere about four inches on 

 each side of a straight line, and w ere alternately on this Bide and on that. 

 Three such impressions were distinctly visible, and doubtless on tin* same 

 face of the slab more w ould have been met w ith, 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, 



