GEOLOGY 



conformity by the so-called Lower Permian rocks. The Coal Measures 

 lie in a syncline or trough, the axis of which extends in a north and 

 south direction, and on all sides the beds dip towards this line. The 

 northern part of the coalfield is bounded by faults or lines of fracture, 

 along which the rocks on either side have been relatively shifted, so that 

 here various newer rocks, the ' Permian ' and Trias, abut against the 

 Coal Measures. Mr. Fox-Strangways thinks it unlikely that the Coal 

 Measures will be found to extend continuously under the Trias into the 

 Leicestershire coalfield. In the other direction however they extend 

 southwards under the ' Permian ' of Baxterley, and come to light again 

 as a small ' inlier ' at Arley. South of Bedworth both the Coal 

 Measures and ' Permian ' are covered unconformably by the Trias, 

 and the seams have been worked through this last as far south as the 

 Craven Colliery, three miles north-east of Coventry. Beyond this the 

 outcrops are said to curve round towards the south-west. 1 



It becomes an interesting and important question as to whether or 

 not these coals extend continuously under the Trias towards South 

 Staffordshire. There is no reason to doubt that the Coal Measures of 

 the Warwickshire coalfield and those of South Staffordshire were 

 originally deposited in one and the same basin, for in both districts the 

 measures thicken towards the north-north-west, and in the opposite 

 direction the coals approach each other by the thinning out of the 

 intermediate beds, and tend to combine into one or two seams of 

 abnormal thickness. It thus, in Professor Lapworth's 2 words, ' becomes 

 a matter of high probability that the Thick Coal of South Staffordshire 

 extends more or less continuously under the Red rocks of North 

 Warwickshire, possibly from Hawkesbury to Smethwick.' At the same 

 time it must be borne in mind that land apparently lay to the south and 

 south-east during Coal Measure times, and in that direction the coals 

 may be expected to die out ; again, it is always possible that there may 

 be local unconformities and ' wash-outs ' within the Coal Measures 

 themselves, and it is just possible that areas of post-Carboniferous folding 

 and denudation may lurk concealed and unsuspected under the unriven 

 cloak of Trias. 



According to Professor Lapworth 3 the Warwickshire Coal Meas- 

 ures may be grouped in descending order as follows : 



4. Grey and red sandstones and shales, with one or more bands of Spirorbis 



limestone. 



3. White and yellow sandstones and shales. 

 2. Red and green brick-clays and marls. 

 i. Grey sandstones and dark shales with five workable coal seams, and 



beds of fireclay and ironstone. 



The base of the series was first worked out in detail in 1886 by 

 Mr. Strahan. 4 He found the lowest beds to consist locally of buff or 



1 Howell, 'The Warwickshire Coalfield,' Mem. Geol. Survey, p. 22. 



2 Proc. Geol. Assoc. xv. (1898), 369. 3 Ibid. p. 368. 



* Geol. Mag. (1886), p. 540 et seqq. ; also Geol. Survey map, sheet 63 S.W. new ed. (1886). 



II 



