74 DR ROBERT KIDSTON ON THE 



Upper Coal Measures — and be treated as a distinct passage series, and for them I 

 proposed the name of Transition Series* 



The term "Transition Series" was, however, rather indefinite, and also had been 

 previously used for rocks of Lower Carboniferous age in Germany, though now seldom 

 or never applied to them in recent works. As my work proceeded, I found that this 

 " Transition Series " occupied a much more important place in British Upper Car- 

 boniferous Rocks than I originally suspected ; so, to prevent any confusion by the 

 use of the term " Transition Series," the term Staffordian Series was adopted for the 

 inclusion of the Newcastle-under-Lyme, Etruria Marl Group, and the Black Band 

 Group as this series is perhaps better developed in that county than in any other 

 district of Britain. The Keele Group, being regarded as the base of the Upper Coal 

 Measures, is excluded from the Staffordian Series and placed in the group to which 

 the name of Radstockian Series was given, t That the Radstockian Series is part of 

 the Upper Coal Measures or Stephanian of the Continent is proved by the fossil 

 flora of the Radstock Series, which has given origin to the term. 



It is not my intention to enter here largely into the geology of the Staffordshire 

 Coal Fields ; but, owing to the period which has elapsed since Parts I. and II. of those 

 papers dealing with their' fossil flora were published, it has been necessary to give 

 a short account of the change of classification which it has been deemed advisable to 

 make, and to show the relationship of the older to the newer terms now in use. 



When writing the first paper of the series, that on the " Fossil Plants found in the 

 Hamstead Boring," the following divisions were employed : — 



Upper Coal Measures . . . From the surface to a depth of 1353 feet. 



Middle Coal Measures . . . The remaining portion of section from 



which I saw fossils, down to Heathen 

 Coal at depth of 1893 feet. 



To these divisions I must shortly refer. In a discussion on Dr Walcot Gibson's 

 paper on " A Boring for Coal at Claverley, near Bridgenorth, and its bearing on the 

 extension westwards of the South Staffordshire Coal Field," read before the South 

 Staffordshire and Warwickshire Institute of Mining Engineers, at the general meeting 

 at Birmingham, February 17, 1913, J Mr F. G. Meachem stated in regard to this 

 section that he had asked the late Mr C. E. de Rance some twenty-five years ago to 

 mark where he thought the "Red Coal Measures" ended, and he drew the line at 

 600 feet from the surface, thus cutting off as Permian 600 feet I had referred to the 

 Upper Coal Measures. As a matter of fact, no plants that could be identified were 

 found till a depth of 729 feet was reached, and the upper portion of the section may be 

 referable to the Permian ; but Mr Meachem does not state on what evidence Mr de Rance 

 came to this conclusion. When I examined the plants from this section, now twenty-five 

 years ago, we were only beginning to feel our way in the classification of these rocks. 



* Proc. Roy. Phys. Soc. Edin., vol. xii. p. 228, 1894. 



t Quart Journ. Geol. Soc, vol. lxi., 1905, pp. 308-321. 



\ Trans, of the Institute of Mining Engineers, vol. xlv. part i. pp. 30-48, 1913. 



