76 Geological Society : — 



elevation, and also with the general direction of the major folds and 

 faults of the Leicestershire Coal-field. The northern part of this 

 ridge, which is apparently a faulted anticlinal, is a very probable 

 source of the angular fragments occurring in the Permian breccias 

 5 or 6 miles to the north-west. 



The author concluded that the Permian rocks of the Leicestershire 

 Coal-field belong to the same area of deposition as those of War- 

 wickshire and South Staffordshire, all having formed part of the 

 detrital deposits of the Permian Lake which extended northwards 

 from Warwickshire and Worcestershire, and which had the Pennine 

 chain on its eastern margin. He pointed out the dissimilar nature 

 of these deposits to those of the eastern side of the Pennine chain 

 from Nottingham to the coast of Durham. There were proofs 

 of the existence of a land barrier, owing to the uprising of the 

 Cai'boniferous, between the district round Nottingham and the 

 Leicestershire Coal-field. The most northerly exposure of the Lei- 

 cestershire Permians is 13 miles S.W. of those of South Notts. 

 He indicated the probable course of the old coast-line of the western 

 Permian Lake. Denudation had bared some of the older Palaeozoics 

 of their overlying Coal-measures, and it is the rearranged talus 

 from the harder portions of these older rocks which now form the 

 brecciated bands in the Leicestershire Permians. 



In an Appendix some igneous rocks found in the Bosworth 

 borings were described. 



2. " On the Superficial Geology of the Central Plateau of North- 

 western Canada." By J. B. Tyrrell, Esq., B.A., P.G.S., Pield 

 Geologist of the Geological and Natural History Survey of Canada. 



The Drift-covered prairie extends from the west side of the Lake 

 of the Woods to the region at the foot of the Rocky Mountains, 

 rising from a height of 800 feet on the east to 4500 feet on the 

 west, the gentle slope being broken by two sharp inclines known 

 as the Pembina Escarpment and the Missouri Coteau, giving rise to 

 the First, Second, and Third Prairie Steppes. 



The author described the older rocks of this region, referring 

 especially to his subdivision of the Laramie Formation into an 

 Edmonton Series of Cretaceous age, and a Pascapoo Series forming 

 the base of the Eocene, and then discussed the Superficial Deposits 

 in the following order : — 



1. Preglacial gravels occurring along the foot of the Rocky 

 Mountains, composed of waterworn quartzite pebbles, similar to 

 those now forming and, like them, produced by streams flowing from 

 the mountains. 



2. Boulder-clay or Till, having an average thickness of 50-100 

 feet, and filling up preexisting inequalities. The clay is essentially 

 derived from the material of the underlying rocks. The smoothed 

 and striated boulders of the western region are largely quartzites 

 derived from the Rocky Mountains ; these gradually disappear 

 towards the east, and are replaced by gneisses and other rocks 

 transported from the east and north-west. Towards the north- 

 west several driftless hills over 4000 feet high appear to have stood 



