310 



EEPORT — 1881. 



Professor G. A. Lebour states, for water-supply purposes it does not 

 appear necessary to notice any of the subdivisions generally recognised in 

 the Magnesian Limestone above the marl slate. 



The following is the series, divided in such a way as appears useful for 

 the purposes of the Committee : — 



1. Yellow Sands : Generally a loose, incoherent, coarse sand with 



more or less calcareous cement, often concretionary, sometimes 

 solid. Very irregular in thickness, from 60 feet downwards, and 

 sometimes absent. Generally with a large amount of water. 



2. Magnesian Limestone : Similar to No. 4, seldom more than a few 



feet (6 to 10) in thickness. Not always present. 



3. Marl Slate : Generally a compact, flaggy, dark grey, thinly-bedded 



horizon, seldom more than a yard in thickness, generally imper- 

 vious calcareous and sandy shale, often forming a fish-bed. 



4. Magnesian Limestone : Concretionary, brecciated, compact, and 



cellular, fossiliferous and nnfossiliferons, soft, and earthy in places, 

 eminently hard and crystalline in others. 

 Unconformity. 

 Red Sandstone (with coal-plants) : Of Upper Coal-measure age. 

 Professor Lebour has pi'epared a map of the Durham Coal-field on 

 which the out-crop of the Permian series is shown, as well as the position 

 of all siokings and borings that have been put through the Permian to 

 the Coal-measures, giving the thickness of the Yellow Sand and (where 

 known) the yield of water of that division and of the overlying beds. 



At Middleshrough — Messrs. Bolchow and Vaughans\ 



feet 



Drift 58 



Sandstone and Marls 1148 



Jiock Salt 100 



. Limestone 1 



Conglomerate 7 



ISlT 



Messrs. Bell Brothers', 1874. 



feet 



Drift 77 



Sandstone, Marls, with Gypsum 1050 



SocJi Salt 102 



Soft Rock 32 



Grey Limestone 67 



Gypsum and HocJi Salt 27 



1355 



The beds belong to the Keuper Marls, Waterstones, Lower Mottled 

 Sandstone, and Permian. 



The Pebble-Beds and Upper Mottled Sandstone are absent. 



Eiver Basins of the S^miber Group. 

 NoHh-Eastern Grovj). 



Magnesian Triassic 



Limestone rocks Oolites 



Catchment Basin, XXXVII. .— ., — .. 57 



Eiver Hull .... . . — . . — 



„ Foulness ...— .. 72 , . 8 



