almost always deeply covered with masses of Boulder-clay, gravels, glacier-moraines, raised beaches, and sand dunes, they are seldom exposed to our observation, except in reefs on the shore or in the deep ravines cut by mountain-torrents.
The patches of Secondary strata at present known on the east coast of Scotland are as follows, the enumeration proceeding from north to south (see Map, Plate VII.) : —
Caithness. — I. A small patch forming reefs on the shore a little north of Green Table Point. Age. Upper Oolite.
Sutherland. — II. Several masses of strata almost continuous, between Green Table Point and Helmsdale. Age. Upper Oolite.
III. A continuous band of strata between Helmsdale and Allt Chollie (Colyburn). From ¼-½ mile wide. Age. Upper Oolite.
IV. A tract extending from Kintradwell to near Golspie. This attains a breadth of more than 2 miles at Brora, and is by far the most important development of the Secondary rocks in the east of Scotland. Age. From the Trias to the Upper Oolite (inclusive).
Ross. — V. A patch of clays seen at low water on the shore at Port-an-Righ, near the mouth of the Guillam Burn, and a little south of Shandwick Bay. It extends for about three- quarters of a mile between two projecting spurs of Old Red Sandstone. Age. Upper part of Middle Oolite.
VI. A similar but smaller patch, only half-a-mile south of the last, at a place called Cadh'-an-Righ. Age. Base of Middle Oolite, and top of Lower Oolite.
Cromartyshire. — VII. Beds similarly exposed on the shore at Eathie Bay over a length of about three quarters of a mile. Age. Upper Oolite.
Elginshire. — VIII. The ridge of low sandstone hills between Burghead and Stotfield Head, and part of the ridge three miles to the southward, and on the south side of Loch Spynie. The boundaries of these patches are altogether obscured by drift. Age. Trias and Lower Oolite.
Besides these points, at which the strata in question are undoubtedly in situ, there are a number of places scattered through the counties of the north-east of Scotland, especially Elginshire, Banffshire, and Aberdeenshire, where very numerous fragments of the Secondary rocks have been detected enclosed in the Boulder-clays, which are there so extensively developed ; and from these boulders very considerable and interesting series of Secondary fossils have been obtained. In some cases the transported masses are of enormous size, resembling the similar blocks found in the Midland districts of England, and referred to by Prof. Morris* and Prof. Ramsay†, and which will be described in detail in a forthcoming
- Quart. Journ. Geol. Soc. vol. ix. (1853) p. 317.
† Ibid. vol. xxvii. (1871) p. 252.
VOL. XXIX. PART I. I
