Page:Transactions of the Geological Society, 1st series, vol. 3.djvu/47

From Wikisource
Jump to: navigation, search
This page has been proofread, but needs to be validated.


and as yet involved in so much obscurity, may perhaps belong, and which have been ranked in the class called transition by the Germans, since they were supposed to be of higher antiquity than the secondary or flœtz strata of the same school. This bed is found at Loch Eishort immediately following the sandstone, with a common dip, and in every respect perfectly conformable to it. It is readily distinguished wherever it occurs, provided its upper surface be exposed to the weather, and this at very considerable distances, the appearance which it here puts on being that of detached and irregular masses with a deeply honey-combed surface, the cavities being from a foot to two in depth, rounded and perpendicular, while the projecting portions are equally rounded and smooth. No lichen attaches itself to that surface, but whatever its hue be, it weathers to a bluish colour, by which it is visible among all the surrounding rocks. I could find no means of ascertaining its thickness at Loch Eishort, but near Kilbride where it is fairly exposed it is some hundreds of feet thick; I have however reason to imagine that this dimension is very variable. It may be traced where it first appears at Loch Eishort from the point where it is in contact with the sandstone, for a considerable way up the hills in the direction of Broadford, but is at length lost amidst trap and syenite, and amongst the mossy and deep soil of this rough ground. Pursuing the line of shore it shortly disappears, other beds coming in the way which will follow next in the order of description; but it is recovered at Kilbride, and hence may be traced through the remainder of its connections to the no small surprise of the geologist. As the sandstone bed does not exist at Kilbride the identity of the limestone cannot here be proved by that of the beds on which it reposes; instead of sandstone indeed its lower surface is found in contact with the syenite already generally