SUCCESSION IN THE TEENT BASIN. 



471 



Nottingham Naturalists' Society in 1879. He says: — " It is best 

 seen, however, in a large ballast-pit, off Stony Street, Beeston, where 

 it consists of well-rounded pebbles interbedded with thin seams and 



fig. 4. — Contorted Inteir/lacial River-gravel^ Gamston, near 

 Nottingham. 



H- 



broad irregular bands of dull brown sand. The bedding is mostly 

 horizontal ; but in some parts, where the sand beds are interwedged 

 with the gravel, they slope (and are current-bedded) towards the 

 south-east, indicating that the water which brought the sandy sedi- 

 ment came from the north-west. The pebbles are chiefly quartz 

 and quartzites, but there are besides pebbles and boulders of Coal- 

 measure sandstone, chert, Lower and Upper Keuper, while about 

 10 per cent, are flint chips, with a few perfect flints. The drift, 

 which is here from twelve to fourteen feet thick, is seen resting on a 

 level floor of Bunter pebble-beds. The section in the gravel-pit 

 shows signs of having been disturbed by some force acting laterally 

 in such a way that in some parts where the gravel is bedded the 

 alternations of sand and gravel have been squeezed into folds and 

 sharp convolutions." The deposit is about a quarter of a mile in 

 width, and extends from Chilwell as far as Tottle Brook, along the 

 north-west side of the highroad. 



Another large crescent-shaped patch of gravel occurs at Gamston, 

 south-east of Nottingham. This deposit extends from a point a 

 little to the west of the canal, in an easterly direction about 

 half a mile beyond the "]Eox and Crown." It is breached by a 

 small brook near Gamston, and also by the Thurbeck river. Two 

 sections may be seen — one in the village of Gamston (fig. 4), where 

 the gravel is highly contorted, and another west of the " Pox and 

 Crown." 



2. Later Pennine Boulder-day. 



The mild climatic conditions which for such a considerable period 

 obtained dnring the deposition of the Interglacial River-gravel again 

 gave place to an arctic climate, and glaciers once more formed in the 

 higher valleys and advanced to considerable distances over the 

 surrounding lowlands. From the wides])read distribution of the 

 Boulder-clays thus formed, and the distant erratic boulders they 

 contain, this stage must have been one of confluent glaciers and 

 great cold. 



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