MARINE BEDS IN THE COAL=MEASURES 

 OF YORKSHIRE. 



J^KIil.lMINAKV NOTICK. 

 WAIXOT (ilBSON, B.Sc, F.G.S. 



Renewed attention has been of late paid to the occurrence of a 

 marine fauna at several horizons in the Middle or Productive 

 Coal-measures of North Staffordshire. Until igoo, references 

 to the existence of marine beds in the Derbyshire, Nottingham- 

 shire, and Yorkshire Coal-measures, excepting the bed imme- 

 diately above the Gannister Coal, were restricted to Green's note 

 on the presence of Avicuiopecten {Pieriiwpccten)^ and Goniatites 

 below the Ackworth rock. During the re-survey of the 

 Derbyshire and Nottinghamshire coalfields, Mr Wedd and 

 myself have been enabled to detect at least three marine beds 

 occurring" at widely separated horizons in the Productive Coal- 

 measures ; and as regards Derbyshire, Nottinghamshire, and 

 southern Yorkshire these are found to contain a constant fauna, 

 and to occupy well defined positions in the Coal-measure 

 sequence. 



The lowest horizon occurs above the Alton Coal of Derby- 

 shire (Gannister Coal of Yorkshire), and contains a rich 

 Goniatite fauna. The next horizon is met with about 300 feet 

 above the Deep Hard Coal (Park Gate, Old Hards, Two Yards, 

 Brown Metal, and Firthfields coals of Yorkshire). The fauna 

 consists of Goniatites^ Pterinopecten, Myalina^ Lingula, and 

 Prodiictus ; the strata, consisting of black shales, layers of 

 nodules of ironstones, and pale blue shales. A third horizon, 

 of exceptional interest, has been traced from Gedling, near 

 Nottingham, to Mansfield, and as far north as Doncaster, at a 

 vertical distance, varying from 524 feet to 600 feet above the 

 Top Hard Coal of Nottinghamshire (Barnsley Coal of York- 

 shire), or 250 feet above the High Hazles Coal (Kents Thick 

 Coal and Mapperwell Coal), or 200 feet above the Clowne 

 Coal ( ? Wathwood Coal of Yorkshire). The fossils are found 

 in pale blue shales ; with a blue argillaceous limestone, 

 weathering brown, near the base. 



This horizon contains a unique Gasteropod and I'ish fauna, 

 and is also rich in marine Lamellibranchiata. 



Apart from their scientific interest, considerable economic 

 importance attaches itself to these marine horizons. Mining 



