Appendix II. NOTE ON THE STRATIGRAPHY OF ROULSTON SCAR

Abstract

A short visit to Roulston Scar in December, 1917, yielded the following information :— (1) Towards the northern end of the Scar the break between the Calcareous Grits and the underlying Kellaways is sharply defined ; the Corallian consisting of a fine-grained non-ferruginous grit contrasting with the ochre-coloured Kellaways. Towards the southern end, however, this junction is not so readily seen, the lower beds of the Calcareous Grits being largely ferruginous. (2) The top of the Kellaways appears to be everywhere marked by a bed consisting largely of rolled fragments of Belemnites together with smaller nodules ; the nature of this deposit forcibly calling to mind the two beds of rolled fossils and phosphatic nodules in the Gault and pointing to pene-contemporaneous erosion. (3) The general section below the Calcareous Grits is approximately as follows :— Ferruginous sandstone, shrly in parts, crowded with water-worn fragments of Belermnites, apparently belonging to the following species : B. abbreviatus and B. oweni, 4 to 6 inches ; ferruginous sandstone, unfossiliferous, about 1 foot ; ferruginous sandstone, fossils abundant but very badly preserved, Trigonia allied to T. clavellata, Pecten inaequicostatus and P. demissus, Hinnites sp. together with a few fragments of belemnites and unrecognisable fossils, about 10 inches. [From apparently the same bed at the southern end of the Scar two species of ammonites were obtained ; these were sent to Mr. S. S. Buckman, who wrote— “Roughly speaking your Amm. show a Macrocephalites indicating top of the Cornbrash ( macrocephalus zone, base of the ...