GEOLOGY 



the local supplies of water to the villages and farm-houses, sources 

 which are liable to pollution in populous places through surface con- 

 tamination. 



Pseudomorphous crystals of rock salt have been occasionally found 

 in the Keuper Sandstones, while in the Keuper Marls the presence of 

 rock salt is indicated by the occurrence of brine springs. 



These springs in Worcestershire have been known since the Roman 

 occupation, but the deeper-seated and stronger springs were not proved 

 until much later, that of Droitwich in 1725, and Stoke Prior in 1829. 

 At Stoke Prior a shaft was sunk and a small amount of rock salt obtained ; 

 subsequently a boring was carried to a considerable depth. At Droit- 

 wich a shaft has been sunk 80 feet and a boring carried to a total depth 

 of 210 feet through soil, drift, red marl and gypsum, and red marl with 

 rock salt. Here as at Stoke Prior the deeper borings now extend to 

 about 1,000 feet. At both localities the brine is copious, and when not 

 kept down by pumping, it rises to the surface. At Droitwich the town 

 and neighbourhood have been affected by the pumping from the brine- 

 pits, and subsidences have occurred through the loss of material under- 

 ground.' 



H. E. Strickland in 1842 drew attention to some old salt works on 

 DefFord Common, mentioning that seventy years previously (about 

 1770) a shaft was sunk to a depth of 175 feet, and that brine then over- 

 flowed. The lowest bed penetrated was the grey marl of the Triassic 

 series, which occurs on top of the red marl.^ Saline water has been 

 encountered at Aberton, north-east of Pershore, the village being situated 

 on a faulted junction between the Red Marl and Lower Lias. A salt 

 well to the south of Dudley, known as Lady Wood Saline Spa, is situ- 

 ated on the Coal Measures. 



The red marls and sandstones were deposited in desert regions with 

 inland salt lakes, the area being subject to wet and dry seasons ; in the 

 former the clayey or marly sediments were laid down, in the latter the 

 rock salt was precipitated.^ It is not unlikely that some of the sandy 

 Triassic layers were drifted by winds, especially those which are re- 

 markably false-bedded. 



On top of the Keuper Marls we find a series of passage-beds which 

 connect the Triassic with the Liassic formations. These are the Rhatic 

 Beds, so named from the Rhstian Alps in the Tyrol, and they indicate 

 the incoming of marine conditions, perhaps locally in the form of a large 

 inland sea like the Caspian. 



The Rhsetic Beds occur in the outliers south of Upton-on-Severn, 

 and at Bushley on the right bank of the Severn. 



Their main outcrop lies on the left bank of the Severn from Hill 

 Crome northwards to Norton near Worcester, and Dunhampstead, where 

 the beds are shifted by faults. They occur also north and west of 



* J. Dickinson, Report on Landslips in Salt Districts, 1873. 



* Proc. Geol. Soc, vol. iii. p. 732. 



' See T. Ward, Trans. Manchester Geol. Soc, vol. xviii. p. 396. 

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