Pengelly— Devonian Rocks of Torhay. 21 



tion to a few probably unique facts connected with them, which are 

 well displayed in the limestones along the southern shore of Torbay, 

 and especially at a small beach almost immediately beneath Berry 

 Head House, about midway between the Head and Brixham. 



At the spot indicated, the limestones dip at a low angle towards 

 the south or landward, and the joints of both systems are occupied 

 with vertical dikes or wall-like masses of compact tolerably fine- 

 grained red sandstone, which are traceable at by no means wide 

 intervals from Berry Head to the Torbay and Dartmouth Eailroad. 

 There is no manner of doubt that the dikes belong to the Triassic 

 or New Eed Sandstone formation, which is so fully develoiDed in the 

 central shores of the bay. It may be presumed, therefore, that this 

 formation formerly covered the Berry Hea'd limestone : and, indeed, 

 there is further evidence of this in the fact that diminutive outlying 

 patches of red sandstone and conglomerate are met with here and 

 there throughout the district. It is obvious too that both systems 

 of joints were in existence during, but not necessarily before, the 

 Triassic era. 



A careful inspection of the dikes discloses the fact, that in every 

 instance of intersection, the north and south series cut through 

 those running east and west. It is also observable that there 

 is a perceptible, though comparatively slight, difference in the 

 colours of the two systems. We, therefore, advance another step, 

 and conclude that the dikes running north and south are more 

 modern than those through which they pass ; but we may proceed 

 still further ; for it is obvious that had the north and soTith joints 

 been in existence when those having an east and west direction were 

 filled in with red sand, they would have been filled in also, and the 

 two systems of dikes would have been of the same age ; hence we 

 may safely conclude that the north and south joints were formed 

 after the east and west dikes, and therefore that the joints having a 

 north and south direction are not only more modern than those run- 

 ning east and west, but that they were absolutely formed after the 

 commencement of the New Red Sandstone era. 



It requires but little reflection, however, to advance another 

 step ; for since the north and south joints are filled with red sand- 

 stone dikes, they must have been formed before the close of the 

 Triassic era. Here, therefore, we have, what so far as I am aware, 

 was never produced before, conclusive evidence that the north and 

 south joints of the Devonian rocks of the Torbay district are of 

 Triassic age; and assuming that the joints having the same direction 

 in Devon and Cornwall generally, are all of the same age, it follows 

 that the entire district is brought under this generalization. 



These dikes, moreover, bring before us very prominently the 

 enormous amount of time which the red rocks of this district repre- 

 sent ; and this is seen most clearly when a ground plan or bird's- 

 eye view of the phenomena is studied. It then appears (1) that 

 the east and west dikes are not only intersected but faulted ; and 

 (2) that they are traversed by longitudLaal veins of carbonate of 

 lime, which do not enter the intersecting dikes. Hence we are 



