﻿Vol. 6 J.] THE MARINE BEDS LN THE COAL-MEASfTRES. 495 



24. The Marine Beds in the Coal-Measures of North Stafford- 

 shire. By John T. Stobbs, F.G.S. With Notes on their 

 Palaeontology by Wheelton Hind, M.D., B.S., F.R.C.S., 

 F.G.S. (Bead January 4th, 1905.) 



[Plates XXXIV-XXXVL] 



Contents. 



Page 



I. Introductory Remarks 495 



II. The Significance of Marine Horizons in the Coal-Measures 496 



III. The Marine Horizons in the North-Staffordshire Coalfields 498 



IV. Explanation of the Map (PI. XXXIV) 513 



V. Description of the Deposits 514 



VI. Scheme of Subdivision of the Coal-Measures in North Stafford- 

 shire by means of Marine Bands 516 



VII. Correlation of various Coalfields by the Use of Marine Horizons 519 



VIII. Conclusion 522 



IX. Bibliography 523 



X. Notes on the Palaeontology 527 



I. Introductory Remarks. 



The North- Stafford shire Coalfield offers exceptional facilities for the 

 study of Coal-Measure geology. It is remarkably rich in deposits 

 of coal, ironstone, and marl, which are being worked by means 

 of a comparatively-large number of mines arid quarries ; and, by 

 reason of the excessive folding and faulting of the Measures, the 

 whole sequence is exposed within a moderate area. The number of 

 these exposures is further increased by the shaft-sinkings and cross- 

 measure drifts which are rendered necessary by the disposition of 

 the strata, and are constantly in progress in some part of the 

 district in the process of mining the different beds. Each of these 

 operations, therefore, not only reveals a section of the strata, but 

 also provides a large quantity of material for search and examina- 

 tion. In order, however, to reap the fullest benefit from such 

 opportunities, it is necessary to inspect the excavated debris almost 

 day by day, so that the stratigraphical position of each fossiHferous 

 band may be located in situ, with exactness. It is obvious that 

 this can only be performed by local workers ; and, during the past 

 six years, I have taken advantage of these opportunities for minute 

 and careful examination of the individual beds of the Coal-Measures, 

 chiefly with the purpose of establishing a more satisfactory correla- 

 tion of the seams in the different areas of the Coalfield. Fortunately, 

 the work has added to our knowledge of the prevalence of marine 

 conditions during the period of deposition in the Midlands of those 

 Measures which contain the most valuable coal-seams, and were 

 for that reason denominated by Ramsay ' the true Coal-Measures/ 



