650 EEPORT — 1891. 



6. Note on Boulders at Darley, near Matloclc, Derhysliire. 

 By Heebekt Bolton, Assistant Keeper, Manchester Museum. 



During the excavation for a small lake close to the Midland Kailway StaticH 

 at Darley, near Matlock, a cluster of fifteen boulders was exposed, the size of 

 several being sufficient to justify an examination. The size of the largest boulder 

 was 10 feet x 6 feet x G feet. 



The boulders lay in a bed of boulder clay which had a thickness of nine 

 feet. 



The upper part of the clay was of a strong yellow colour and very stiff. Below, 

 the colour varied from yellow to brown and red, and pockets of sand were com- 

 mon. 



Only two boulders were well rounded, the rest being sub-angular ou their upper 

 half, and fairly angular on the lower. 



All the boulders consist of gritstone identical in character with the Chatsworth 

 grit of the adjoining hills. 



No striations occur on the boulders, but this may be due to the original surface 

 having crumbled away. 



A series of parallel and shallow grooves occurs on the side of the largest boulders, 

 and a deep hollow has been scooped out of its southern face. 



The major axis of the undisturbed boulders was approximately north and 

 south, the general direction for the cluster being 8° west of north. 



The blocks were arranged in the order of their weight in a north to south 

 direction. 



The clay was fouud to rest upon a deposit of the nature of river gravel. 

 The writer is of opinion that the clay is redistributed boulder clay brought 

 down from the adjoining heights, and that the boulders were brought down at the 

 same time from the line of outcrop of the grit. 



He is led to this conclusion by the local character of the boulders, the almost 

 total absence of foreigners, and the character of the clay. 



The red and brown colour of the latter at its base seems to show that oxidation 

 of the contained iron has proceeded for a longer time than in the case of the upper- 

 most clay. 



This would be expected if the clay was redistributed, for the basement mass of 

 clay must have been the superficial clay of the heights. 



The enclosed sand would also indicate the complete disintegration of boulders 

 of gritstone, &c., whilst the clay was in its primary position. 



The amount of disintegration which has taken place since redistribution is 

 marked by the crumbling surface of the large boulders. 



The general direction of the boulders may be explained bj' noting that the 

 river flows from north to south. 



7. Notes of a Section of Drift at Levenshulme, Manchester. 

 Bij Percy F. Kendall, F.G.S. 



In the construction of a new railway between Chorlton-cum-Hardy and 

 Fairfield a good opportunity was afforded of studying the effects of land-ice. 

 The part of the cuttings particularly observed was that extending from Fallow- 

 field almost to the L. and N.-W. Railway at Levenshulme, in a line almost 

 accurately from west to east. 



Throughout the whole distance the solid geology was displayed with a 

 covering of boulder clay. The rocks consisted in descending sequence (and from 

 west to east) of triassic pebble beds (fault), Permian marl, Permian sandstone, 

 and upper coal measures containing several beds of Ardwick limestone (see 

 * Brockbank and De Ptance, Mem. Manch. Lit. and Phil. Soc.,' 4th Series, 

 Vol. iv.). The triassic rocks when soft were much mangled and crushed at their 

 contact with the drift ; but in places, nearly horizontal intrusions of boulder clay 

 were interposed between the bedding. These intrusions always entered from the 

 west. 



