W. J. Harrison — Deep-Boring in Keuper Marls. 453 



V. — On a Deep Boring in the JSTew Eed Mauls (Keuper Marls) 

 near Birmingham. 1 



By "W. Jerome Harrison, F.G.S. 



THE Triassic strata which form the country surrounding Birming- 

 ham consist of the usual divisions of sandstone and marl ; the 

 sandstones predominating below, the marls above. In the immediate 

 neighbourhood of the town, the sandy beds are divided from the 

 marly or clayey strata by a dislocation or line of fault which runs 

 from north-east to south-west, taking a line from Erdington to 

 Eubery, and traceable altogether for a distance of about twenty 

 miles. The fault runs through the town of Birmingham nearly 

 parallel to the Biver Bea, and from a quarter to half a mile west of 

 the present bed of the river. The Lower Keuper sandstone, which 

 forms a surface band one to two miles in width on the west of this 

 fault, is a porous stratum about 200 feet in thickness. It is under- 

 lain by the Bunter Pebble Beds, 300 to 400 feet in thickness, which 

 crop out further to the west, and which contain an inexhaustible 

 supply of water. From three deep wells in the suburbs of Birming- 

 ham — two on the north at Perry and Witton, and one on the south 

 near Selly Oak — the Corporation Waterworks obtain daily a supply 

 of over eight million gallons of water, most of which comes from 

 the Pebble Beds, which occupy the lower portion of each well or 

 bore-hole. The water is of good quality, showing from nine to fifteen 

 degrees of hardness. 



On the east of the line of fault a very different state of things 

 prevails. The rocks on this side have been dropped vertically some 

 six or seven hundred feet. Here the surface is composed of the 

 Keuper Bed Marls, which form a broad band ten or twelve miles in 

 width, extending from Birmingham tp Shustoke. The water-supply 

 of this tract — which has a considerable extension to north and south 

 from Tamworth to Warwick and Bedditch — is wholly derived from 

 superficial sources, such wells as exist drawing their water from the 

 post-glacial sands and gravels which lie here and there in hummocks 

 on the Bed Marls. 



As the population on this agricultural plain of Warwickshire 

 is comparatively small and scattered, and as there are no manufactur- 

 ing towns in the district, it is, perhaps, not surprising that until quite 

 recently no attempts have been made to reach the buried waters 

 which probably exist in the Bunter and Keuper Sandstones that 

 underlie the Bed Marls on the east of the line of fault. The chief 

 obstacles to such an undertaking are the unknown — certainly consider- 

 able — thickness of the Bed Marls ; and the fact that no one likes 

 to be the first to experiment in a matter in which — while there is 

 certainly a possibility of failure — any good result obtained would 

 be quite as much for the benefit of one's neighbours as for one's self. 

 It would seem that such borings might be executed by Government, 



1 Eead before Section C. (Geology), British Association, Birmingham, September 

 3rd, 1886. • 



