150 



THE GEOLOGIST. 



the Ochils towards Dunning and Tereagles in Perthshire. These 

 tilestones, and the grey and red sandstones with which they are 

 systematically associated, occupy the whole superficies of that well- 

 known and beautiful tract of country which is bounded by the old 

 crystalline rocks of the Grampians on the north, and by the later 

 felspathic Ochil range on the south ; and it includes the celebrated 

 geological localities of Cavonylie, Glammis, Forfar, Kinnordie, Clash- 

 bennie, Babruddery, and Parkhill. 



The strata all dip off from the Grampians, generally in a south- 

 easterly direction, and at various degrees of inclination. They rest 

 on a great coarse foundation of conglomerate, the true equivalent of 

 the fundamental conglomerates of Caithness and Sutherland ; and 

 thus they constitute, with the absence of some members of the series, 

 component parts of the Lower Division of the old red sandstone. The 

 thickness of the group may be estimated at about two thousand feet, 

 the deepest section of which is exposed in the quarries of Balbeuchlie, 

 and which, uptilted at various angles, protrudes along the ridges and 

 numerous valleys of the highest crest of the Sidlaws. There are, 

 in the line of strike from north to south, two well-defined synclines 

 and three anticlines, occasioned by the upheaval of the trappean 

 formations. 



A new opening was lately made into the tilestone-beds at Tealing ; 

 and, as it has proved so exuberantly rich in fossil remains, I shall 

 confine the few observations I have now to make to this most 

 interesting locality. I visited the spot in February last, in company 

 with Lord and Lady Kinnaird, Sir John and Lady Jane Ogilvy, and 

 an enthusiastic party of juveniles of both sexes, some just fresh from 

 their Oxford studies. 



The fossiliferous bed of " Tilestone " rests upon bands of highly 

 micaceous flagstones, the well-known " Carmylie pavement," and is 

 overlaid by strata of similar lithological structure and mineral con- 

 stituents. The ripple-marked bands are above as well as below, and 

 the tilestone itself is often deeply indented by the wavelets. The 

 distinguishing characteristics of the tilestone consist in its finer 

 texture, more fissile lamination, and deep blue colour, — which often 

 render it, in hand specimens, difficult to be distinguished from the 

 old clay-slate. 



