Page:Transactions of the Geological Society, 1st series, vol. 4.djvu/187



If we proceed to the western side of this promontory for the purpose of recovering these strata, we find them at Duntulm, from which place they extend interruptedly for a few miles along this shore, when they finally disappear. The same organic remains, the same shale, the same limestone, calcareous sandstone, and siliceous schist, mark the identity of these with the strata on the eastern side, an identity still further confirmed by the prevailing correspondence of their inclinations. I may at the same time add that a greater facility of access to the upper beds, the only ones here to be found, assists us in obtaining a more correct notion of those beds which from their elevation above the shore are inaccessible on the east side, and that we thus become acquainted with those numerous varieties of the lias limestone, which having often been described by geologists, serve to confirm the nature of these last and uppermost of the stratified rocks of Sky. The nature and origin of siliceous schistus can here also be traced in many other places besides that most conspicuous one at Duntulm which I formerly described; and so many gradations between that rock and shale are to be observed that the most satisfactory evidence of their connection can be obtained.

From a comparison of these several facts, the details of which I have from the nature of this supplementary paper thought it necessary to condense, it is apparent that the fundamental rocks of the district of Trottemish, are those secondary and stratified substances which are connected with the lias formation, and that these are both surmounted and intersected by trap. If but little additional evidence of this view can be obtained from an examination of the interior country, that little is at least satisfactory. The same substances occur in numerous places, where precipitous faces or the sections formed by rivers expose the rocks that lie beneath