2 c6 PProc. B.N.F.C, 



The River Roe at this place affords to the geological student one 

 of the best sections to be seen in the district of the metamorphic 

 rocks. The rocky channel of the river is cut into successive beds 

 of massive micaceous and chloritic schists. The rocks are all 

 more or less calcareous, and at one or two places further down the 

 river partake decidedly of the character of limestone schists. 

 Outside of the river course few exposures of the solid rocks occur. 

 Speaking generally, the metamorphic series occupies the western 

 side of the Roe Valley, the Triassic and Mesozoic series the 

 eastern side, the latter capped by the massive escarpments of the 

 Tertiary basalt plateau. Northward near Limavady town the river 

 enters an alluvial flat, where the only eminences of consequence 

 are terraces and drumlins of sand and gravel, evidently of glacial 

 age. The whole party remained near the Dog Leap for over an 

 hour. The collectors had a busy time, and the photographers 

 took advantage of their opportunities. 



The Electric Light and Power Station (the property of Mrs. 

 Ritter) by which Limavady is lighted, is situated at the Dog Leap, 

 and to it a visit of inspection was paid. 



As is well known the Roe Valley occupies the focus, as it 

 were, of the ancient territory of the once powerful sept of the 

 O'Cahans. Roderic M'Manus O'Cahan, whose downfall took 

 place in Queen Elizabeth's reign, was the last territorial prince of 

 the house in this district ; and the foundations of his ancient 

 stronghold still remain on the east side of the Roe, a short 

 distance north of the Dog Leap. A little bit further north, and on 

 the east side also, a very high and projecting rock overhangs the 

 river, which is known as O'Cahan's Rock. On emerging from 

 the woods at the Swing Bridge, the more active members decided 

 to visit O'Cahan's Rock and also the Holy Well, which latter is 

 also situated in the woods on the east side of the river. Per- 

 mission to visit it had been kindly granted by B. H. Lane, Esq. 

 Shortly after three o'clock all met again at the Bridge and then 

 passed over to the demesne of Roe Park House, where they were 



