80 EEPORT — 1889. 



Feet. Feet. 



Red and white sandstone 22 



Red marl 1^ 



Coarse red sandstone ....... 20| 



Red marly „ 20 



Red marl 28 



Soft grey sandstone 47 



Hard white „ 16 



478 / Fine soft red sandstone 52 



479 Red sand 1 



640 ■ Soft red sandstone 161 



Blottled „ 3 



687 ^ Soft red „ 44 



The lower soft beds were found very water-bearing ; the di]} was to 

 the north, at 6h°- 



Yorlcshire and Durham. 



Professor Lebour states : for -water-supply purposes it does not 

 appear necessary to notice any of the subdivisions generally recognised 

 in the Durham Magnesian Limestone above the marl slate. The following 

 classification gives the important divisions for water-supply purposes : — 



1. Magnesian limestone : concretionary, brecciated, compact and cel- 

 lular ; varies from an eminently hard and crystalline condition to an 

 earthy one, and from containing many fossils to none at all. 



2. ' Marl slate,' a compact, flaggy, dark grey, calcareous or sandy 

 shale, often forming a ' fish bed,' generally impervious, and a yard in 

 thickness. 



3. Magnesian limestone, resembling that below, generally 6 feet to 

 10 feet thick, sometimes absent. 



4. 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 ; 

 contains a lai'ge amount of water. 



Uncovformity , — Red Sandstone with Coal Plants (Upper Coal-mea- 

 sures). 



Professor Lebour has mapped the Durham coal-pits, and indicated the 

 outcrop of the Permian series, as well as the position of all sinkings and 

 borings that have been put down to the coal-measures, through the 

 Permian. 



The numerous sections obtained in boring for rock salt, from Middles- 

 borough to the district south of Hartlepool, have clearly defined the 

 area where potable water may not be looked for. The boring put down 

 in 1859, for Messrs. Bolckow & Vaughan, was made to procure a water 

 supply for their well-known ironworks. Large supplies of water were 

 obtained from the upper pervious strata ; but it contained so large a 

 quantity of sulphate of lime as to be useless for the purpose requii-ed, 

 and the boring was discontinued at a depth of 1,313 feet, the details of 

 which are given in the Sixth Report of your Committee. ^ 



Since the publication of these details, papers have appeared by Mr. 

 E. Wilson, P.G.S., and Mr. W. J. Bird. The latter author gives a classi- 

 fication of the measures passed through, which is valuable in correlating 



' In the Sixth Report, 1881. The beds bored throug-h are described by your 

 Reporter as belonging to 'the Keuper waterstone, lower mottled sandstone, and 

 Permian.' In the Seventh Report this classification is again alluded to. 



