FOREST OF WYRE AND TITTERSTONE CLEE HILL COAL FIELDS. 1013 



bottom upward to the base of the "Permian" [ = Keele] Beds, and that 

 such strata are not restricted, as elsewhere in the Midlands, to the Etruria 

 Marls. But this suspicion will not be confirmed, or disproved, till the whole 

 area has been mapped in detail. 



2. This confirms the opinion of Mr Daniel Jones, based on the correlation of the 



Sweet Coals of Wyre Forest with those of Coalbrookdale and South Stafford- 

 shire. It also agrees with the conclusions arrived at by myself from 

 Dr Kidston's examination of the plant-remains collected in 1895. 



3. This confirms Dr Kidston's determination of the age of the plant-remains 



collected by myself in 1895 from the surface-beds exposed at Cooper's Mill, 

 close by. 



4. This agrees with the results arrived at by Drs Gibson and Kidston, though the 



latter observer suspects the presence of Lanarkian Measures also (p. 1081). 



5. To Dr Arber alone belongs the credit of having been the' first to identify the 



flora of the Sulphur Coal Group of Mamble as of Transition age. Dr 

 Kidston, however, feels justified in going further, and refers the series in 

 question to the Newcastle subdivision of the Staffordian ( = Transition) 

 Series (see above, p. 1000). 



6. This conclusion — that in the Highley region the Sulphur Coal Group is uncon 7 



formable to the Sweet Coal Group — is of such theoretical and practical im- 

 portance that it deserves more than a passing comment. We have already 

 seen (pp. 1004, 1006) that the distribution of these two groups is anoma- 

 lous. North and south of the Highley region it is the Sulphur Coal Group 

 that rests upon the Old Red Sandstone floor ; at Billingsley and Harcott, 

 and thence to Baveney Wood, the Sweet Coal Group comes between. This 

 can be explained either (l) as a case of simple overlap, unaccompanied by 

 unconformity, or (2) as an instance of overstep, the Sulphur Coal Group 

 spreading unconformably across the edges of the Sweet Coal Group. In 

 1895 I was of opinion that the latter was the explanation, as it seems to be 

 in the Coalbrookdale field, if the views of Marcus Scott and Mr Daniel 

 Jones are right. But the theory has never been definitely proved in the 

 case of Wyre Forest. Mr Daniel Jones's " outlier" theory involves a deep 

 and wide-spread denudation of the Sweet Coal Measures prior to the 

 . deposition of the Sulphur Coal Group, in order to explain the disappearance 

 of the Sweet Coals themselves somewhere between the Highley region and 

 the Dowles Valley and Shatterford. But though the coals themselves are 

 absent as workable seams, their associated Middle Measures, as shown by 

 the fossil flora, are present in force. The proof of great denudation and 

 unconformity must, therefore, be sought in other facts. 



Dr Arber, comparing the thickness of certain barren measures that inter- 

 vene between the [Main] Sulphur Coal and the Sweet Coal seams in the Highley 



