144 OLD RED SANDSTONE. 



These beds are quarried in places. Scales of fishes occur and 

 also plant-remains: Holoplychiiis has been met with near Jedburgh. 

 The conglomerate rests indifferently on the Cheviot Volcanic 

 Series and on the Silurian rocks ; according to Prof. James 

 Geikie, it may be in part of glacial formation.^ Hungry Law, 

 Carter Fell, and Peel Fell (1964 feet high) are formed of the 

 Calciferous Sandstones. 



Upper Old Red Sandstone, consisting of conglomerate, red and 

 grey sandstone, and cornstone, 600 feet, has been observed in 

 Anglesey, resting unconformably upon the older rocks, and over- 

 lapped by the Carboniferous Limestone." 



In Denbighshire about 80 feet of red conglomerates and sand- 

 stones, with beds of impure limestone (cornstone), rest uncon- 

 formably on the Wenlock Shale. The occurrence of pebbles with 

 Upper Ludlow fossils in these conglomerates has been noticed by 

 INIessrs. A. Strahan and A. O. Walker.^ These beds are now 

 usually grouped as the Basement Beds of the Carboniferous 

 System. 



In the Isle of Man there are certain beds which have been 

 assigned to Old Red Sandstone : they occur in the cliffs north 

 of Peel, and fringe the Carboniferous Limestone north of Castle- 

 town. They consist of brecciated conglomerates, and of fine 

 breccia interstratified with red sandstones : they occasionally con- 

 tain beds of cornstone. Their thickness has been estimated by the 

 Rev. J. G. Cumming* to be 300 feet. The sandstone is extensively 

 quarried at Peel for building-stone, flags, and tombstones. At 

 Castletown Bay, conglomerate occurs, containing pebbles and 

 boulders of sandstone and quartzite. It is overlaid conformably by, 

 and indeed passes up into, limestone of Carboniferous age ; and it 

 rests unconformably on the Skiddaw Slate, as may be seen on the 

 western side of Langness. Conglomerate is also interstratified 

 with the red sandstone in the cliffs north of Peel. These beds 

 have been classed with the Calciferous Sandstone series of Scotland 

 by IMr. J. Horne,^ and they are spoken of as the ' Basement Con- 

 glomerate' of the Carboniferous series, by the Rev. J. C. Ward.® 



In West Somerset, North and South Devon, beds of the same 

 mineral character as the Old Red Sandstone occur in places. In 

 North Devon the Pickwell Down Sandstones are now regarded 

 as the equivalents of the Upper Old Red Sandstone, and near 

 Torquay the Cockington Beds are placed on the same horizon. (See 

 p. 122.) 



^ See articles in Good Words, 1876. 



2 A. C. Ramsay, Mem. Geol. Survey, vol. iii. (edit. 2), p. 255. 



^ Q. J. XXXV. 268. See also A. Strahan, Geology of Rhyl, etc. (Geol. Survey), 



P- 3- 



^ Q. J. ii. 321 ; The Isle of Man, 1848. See also G. H. Morton, G. Mag. 

 iS79,^p. 213 ; J. C. Ward, Ibid. 1880, p. I ; J. Home, Trans. Edm. Geol. Soc. 

 ii. 1874. 



5 Trans. Edin. Geol. Soc. ii. 



^ G. Mag. 1880, p. 4. 



