GEOLOGY 



one of those vexed questions that is really of little consequence. There 

 is not the least doubt that the Rhsetic Beds are passage-beds between 

 the Trias and Lias, but they are generally grouped in this country, as 

 abroad, with the Trias. Curiously enough there is evidence in the 

 vicinity of Bridgend in South Wales of red marly beds on the horizon 

 of the black Rhstic shales, showing that conditions similar to those 

 which attended the deposition of the Keuper Marls locally occurred in 

 Rhstic times. This fact has lately been brought into notice by Mr. 

 R. H. Tiddeman. 



It is worthy of remark that while beds of White Lias occur near 

 Shipston-on-Stour, as they do at Bath and towards the Mendips, they 

 are nevertheless absent or poorly represented over great part of Gloucester- 

 shire and South Worcestershire. A peculiar layer, called the ' Guinea 

 Bed,' has been observed by Mr. Tomes in Warwickshire,^ and this 

 contains an admixture of Lower Lias with Rhsetic fossils. It is not im- 

 probable, therefore, that there was locally an irregular overlap of the 

 Rhxtic Beds, accompanied by reconstruction of some layers, during 

 the changing conditions which ushered in the Lower Lias.^ 



LIAS AND OOLITES 



Following the Rhstic Beds we have the three divisions of the 

 Lias. 



A considerable portion of Worcestershire is occupied by the Lower 

 Lias, which consists of a group of argillaceous limestones, overlain by 

 a thick mass of blue and grey clays with only occasional bands of 

 limestone. The basement limestones are exposed along the scarps 

 from Strensham, Hill Croome, Croome d'Abitot, to Stoulton and Hanbury, 

 east of Droitwich, and they extend near the surface over the northern 

 portions of the Lias area in the county, and again at Hasler Hill, near 

 Evesham, Cleeve Prior, and the neighbourhood. Numerous quarries 

 have been opened in the beds, though fewer are now worked than was 

 the case in past times. Outliers occur at Bushley and at Berrow to the 

 south-east of the Malvern range. 



These lower beds of limestone, which are interbanded with shales, 

 are not much more than 20 feet in thickness, and some of the layers 

 are fissile and banded. They yield plant-remains, Crustacea, such as 

 Eryon, also Ammonites johnstoni, and in the lowest layers Pleuromya crow- 

 combeia, and many examples of Ostrea liassica. Remains of the large 

 reptiles Ichthyosaurus and Plesiosaurus are also found, as well as the fishes 

 Dapedius and Pholidophorus. 



The stone is burnt for lime, while some smooth and even-grained 

 slabs are used for inside paving, others for steps, tombstones, etc. 

 In several locaHties the surface beds of limestone have been disturbed, 

 a feature to which further reference will be made. 



' Quart. Journ. Geol. Soc, vol. xvi. p. 394 ; vol. xxxiv. p. 182. 

 ^ ' Lias of England and Wales,' Mem. Geol. Survey, p. 151. 

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