Vol. 55.] THE ASHBOURXE AND BUXTON EAILWAY. 225 



found among the Yoredale rocks, coarse agglomerates do traverse 

 the Yoredale group at KniTeton.' A careful examination of these 

 cuttings has enabled me to fill this gap in our geological know- 

 ledge. The railway -excavations bring to view no less than four 

 exposures of bedded ash, the existence of which in the Yoredale 

 rocks of this district had not been previously known. They also 

 show a fine series of contorted limestones and shales, which occupy 

 a horizon above the ash. This series of rocks contains numerous 

 intercalations or thin beds of tuff, and many of the limestone-beds 

 in it have volcanic lapilli disseminated through them. Thus they 

 afford a proof of the existence of a vigorous, followed by an inter- 

 mittent, volcanic activity, contemporaneous with the deposition of 

 the Lower Yoredale Beds. 



After crossing under Church Street, Ashbourne, the railway 

 passes through the Bunter Beds in a tunnel, 370 yards long. 

 Unfortunately, I was unable to visit the tunnel before it was 

 bricked in, and, therefore, cannot give any details regarding the 

 structure of the rocks through which it is cut. 



II. Desceiption of the Cuttixgs. 



(1) Sandy brooke. 



The first cutting opposite Sandybrooke is about 730 yards long, 

 and shows a thick deposit of Boulder Clay. It contains pieces of 

 sandstone, grit, and Mountain Limestone, the last often having a 

 well-polished and striated surface. The greater part had been sloped 

 down before I saw it, but the boulders are numerous and project 

 above the surface of the Clay. 



(2) Alders Earm. 



The second cutting, opposite Alders Farm, about 250 yards long, 

 is in Boulder Clay. It contains numerous boulders of Mountain 

 Limestone, grit, sandstone, shales, chert, and igneous rocks foreign 

 to the county. 



(3) Ashes Farm. 



The third cutting, opposite Ashes Farm, Fenny Bentley, about 

 330 yards long, is in Boulder Clay, which in one place is seen to 

 rest upon a bed of sand. A large number of foreign igneous rocks 

 were found here, in addition to boulders from the Carboniferous 

 sedimentary rocks. 



These three cuttings were visited by me after they had been 

 practically finished ; but the others as far as Parsley Hay, where 

 the new railway joins the previous extension from Buxton, were 

 frequently examined during the course of excavation. By this 

 means, much information was gained about the stratigraphy of 

 the beds, which would have been missed had the cuttings only been 

 seen when finished. 



Q. J. G. S. ^0. 218. Q 



