18 



15. The annexed cut (N.W. to S.E.), the lower portion of which 

 on either side of the hill (/) is partly conjectural, represents the 



probable relations of the strata at this highly interesting point. 

 Here (a a) represents the trap of the hill tops, (b b) yellow sand- 

 stones, the highest members of the Ballagan series ; (6' b') probable 

 position of the same beds south of Dunglass hill ; (c) the Ballagan 

 beds ; (d) a trap dike ; (e e) probable position of the lower portion 

 of the Ballagan series on either side of the axis ; (/) Dunglass hill 

 composed of prismatic basalt, and forming the anticlinal axis of the 

 strata and watershed of the valley ; (g h) coarse gritty sandstones 

 higher in the series than the yellow sandstones (b b) ; (k) thick 

 bedded fine grained sandstones, forming the highest parts of Craig- 

 maddie Moor to the west. The beds of this latter dipping S.E. 

 form the floor of the Campsie valley, on the level of the Grlazert 

 rivulet. 



16. The yellow sandstones (b b) at the top of the Ballagan section 

 thin out eastward, and disappear in Campsie Glen, so that the trap 

 here rests directly on the beds (c), or true Ballagan series, which is 

 depressed in this direction, and covered by newer deposits, whose 

 elevated edges, as they successively crop out N.W., are overlaid 

 along the side of the north hill by tabular masses of trap. The 

 south hill, forming the opposite side of the valley, is a perfect coun- 

 terpart of the north, save that the overlying trap is absent. The 

 strata correspond exactly ; and this rich and beautiful vale, through 

 its extent of five miles in length by half-a-mile to a mile in width, 

 owes its peculiar features to the action of powerful denuding forces, 

 probably coinciding with the elevation of the area, at the close of 

 the glacial period, as already indicated (Art. 11.) On account 

 of the great interest of this case, and the economic value of the 

 strata, we subjoin a section representing the principal beds on both 

 sides. The less important members of the series and the faults, with 

 minor irregularities, are omitted. 



