G. Hkkling — Old Red Sandstone of ForfarsJiire. 399 



It must be remarked that the subdivisions in the above table are 

 based purely on lithological characters and are only made for con- 

 venience of description. No breaks in the series exist to my know- 

 ledge, and I am far from supposing that these subdivisions are likely 

 to be traceable for any great distance ; rapid lateral variation in the 

 character of the rocks is too obvious a feature of the Old Red Sandstone. 

 The names applied to the subdivisions are taken from the localities 

 where the series may be typically seen. The thickness of the sub- 

 divisions are estimated from theoretical sections for the most part, and 

 are therefore to be regarded as only approximately accurate. 



The Stonehaven Beds occupj- the shore between the harbour of 

 Stonehaven and the south end of Craigeven Bay, where the great 

 fault is exposed. A mass of fault breccia fully a yard in thickness 

 occupies the line of junction, while the rocks on either side of it are 

 shattered for fully four yards. Fine red sandstone, with numerous 

 thin bands of bright red shale, is the first rock seen on the south side, 

 dipping at about 60° to S. 12° W. Further south several beds of the 

 red marly shale, 50 to 100 feet in thickness, separate light red or 

 yellow sandstones and fine grits, with some bands of grey sandstone 

 and grit. Such is the general character of the series, which is 

 distinctly fine in character as compared with the mass of the Old 

 Eed. About midway between the fault and the town the Lintrathen 

 porphyry dyke cuts across the shore. The dip varies somewhat both 

 in amount and direction, but is always very high, and no important 

 break in this section appears to exist. About the harbour bands of 

 conglomerate appear among the sandstones, marking the passage to 



The Dunnottar Group of coarse red and grey sandstones, grits, and 

 conglomerates which form the bold coast the whole way from Stone- 

 haven to Johnshaven. As I have only been able to examine the base 

 and the top of this series, I shall add no more than that it forms by 

 far the most extensive series of conspicuously coarse deposits in the 

 district. In its conglomerates pebbles commonly range up to a foot or 

 more in length, and yet are astonishingly well rounded. They mostly 

 consist of quartzite. South of Johnshaven several thin lavas are 

 interbedded with the top of this series, with sandstones and coarse 

 conglomerates of porphyrite blocks between. Beyond this the coast- 

 section is interrupted by the mass of Upper Old Red which is faulted 

 in, extending from East Mathers to Milton Ness (described below), 

 and which covers the junction between the conglomerate series and 

 the great mass of lavas which forms its natural top. These lavas 

 occupy the coast southward by Montrose to Lunan Baj', being hidden, 

 however, almost the whole way to Montrose by sand and alluvium. 

 From Lunan Bay their outcrop strikes inland along the summit of the 

 anticline by Friockheim and Letham, near which latter place they 

 finally die out. About Friockheim and Leysmill are numerous quarry 

 sections of the 



Carmyllie Series, which overlies the lavas. Compact red or grej' 

 sandstone is the predominant rock of this series, with subsidiary 

 masses of grey flagstone and blue or red shale, termed ' caulm ' by 

 the quarrymen. Together with their interbedded lavas, these rocks 

 form the whole axis of the Sidlaws, all along which they are quarried 



