316 Rev. A. Irving — Geology of the Nottingham District. 



slight alteration of the shore-line at the horizon where the breccia 

 occurs, deposited upon the much disturbed and denuded Coal- 

 measures, and highly unconformable to them. If therefore the 

 Permian must needs be assigned to the Palaeozoic epoch, the 

 Bunter, it would seem, ought to go along with it; while a boun- 

 dary line drawn above the Bunter would be perhaps more natural 

 and more analogous to the line of demarcation between the Meso- 

 zoic and Cainozoic epochs. Another way out of the difficulty would 

 be, perhaps, to consider the Permian and Bunter as one great tran- 

 sition series. After a careful perusal of the valuable memoir by 

 Prof. Hull on the Permian and Triassic Bocks of the Midland Counties, 

 and thus becoming acquainted with the meagre evidence on which the 

 great line of demarcation between the Bunter and Permian rocks 

 has been drawn in the northern Permian area, the author feels com- 

 pelled to attach some importance to the evidences of continuous 

 deposition which are found in this neighbourhood. 



(3). Tlte Bmiter: — The Lower Mottled Sandstone does not attain a 

 greater known thickness than one hundred feet in the Nottingham 

 and Derbyshire area. Some good sections of it are seen at Basford, 

 Eadford, and Lenton. At the last-named place it has been brought up 

 by a fault of more than three hundred feet throw to a level with the 

 Keuper. This fault may be observed in the lane close to Highfield ; 

 also about a mile to the west, and in the Wilford colliery, where its 

 throw is proved by actual measurem>ent. The "Himlack Stone" on 

 the north side of Bramcote Hill exhibits the junction of the Lower 

 and Middle Bunter, It is marked by unconformability, and a bed 

 of calcareous grit and breccia forms heve the basement of the Pebble 

 Beds. This clear boundary-line is by no means general ; a passage 

 marked by the gradual appearance of pebbles and hardening of the 

 rock is far more common in the district. This passage may be well 

 s6en in several places ; as, e.g. on Nottingham Forest adjoining the 

 race-course, at Basford, and in the road-cutting about a mile south 

 of Mansfield. 



Tlie Middle Bunter is evidently a shore-formation, with thick beds 

 of sandstone, much harder than the Eed and Mottled Sandstones 

 above and below. Intercalated bands of distinctly laminated 

 micaceous deep-red sandstone, semi-consolidated gravels, and true 

 conglomerates, containing an immense variety of pebbles (chiefly 

 of quartzite), some well-rounded, others sub-angular, are its chief 

 characteristics. The general prevalence of "oblique lamination" 

 indicates an area of deposit subject to shifting currents, while 

 the great quantity of sand mingled with the pebbles, as con- 

 trasted with a shingle thrown up by a rolling surf (as e.g. the 

 Chesil Bank at Portland), seems to imply a shore somewhat protected 

 from the open ocean. The cakes and lumps of red and purple marl 

 found in the rock seem to indicate some disturbance of the Permian 

 strata, supposing, as is probable, that they were derived from the 

 Permian marls. The angularity of many of the contained fragments 

 is well preserved, and they appear to have come from different sources 

 at varying distances; even slabs of Millstone-grit and Yoredale 



