INTRODUCTION. 13 



Sequence op the Carboniferous Deposits of the Midlands (England). 



South Staffordshire. — The Coal Measures rest directly on Silurian rock. 

 Warwickshire Coal-field. 



Coal Measures. — Eed beds with spirorbis limestone. Productive measures. 



Millstone Grit. — Hard siliceous rock with bands of shale. 



Lower Carboniferous absent. 

 Coalbrookdale Coal-field. 



Coal Measures. 



Millstone Grit. 



Carboniferous Limestone. 

 Forest of Wyre. — Coal Measures rest on Old Eed Sandstone strata. 

 Forest of Dean Coal-field. 



Coal Measures. 



Millstone Grit. 



Carboniferous Limestone. 

 Shrewshury Coal-field. 



Coal Measures only, resting on Cambrian and Lower Silurian beds. 

 Clee mil Coal-field. 



Coal Measures. 



Millstone Grit. 



Carboniferous Limestone. 



The Carboniferous Sequence in North "Wales. 



^ ,^ f Measures with seams of coal: some earthy marine limestones at 



Coal Meastjees \ , 



y base. 



Millstone Geit Beds of chert sandstones and conglomerate with intervening shales. 



(Black limestone occasionally arenaceous. 

 Upper, grey limestone . . . 500 feet. 



Middle, white limestone . . . 600 „ 



Lower, brown limestone . . . 400 „ 



Basement beds Eed conglomerates. 



The Carboniferous Sequence op South Wales. 



I'TJpper series. 

 Coal Meastjees 'Pennant series. Sandstones and coals. 



[Lower or white ash series. Coals and ironstones. 

 Millstone Geit ? Absent. 



( . rBlack shales and sandstones, with a few dark lime- 



\ stones . . • . 1600 feet. 



Limestone . . . . 500 to 2000 „ 



Lower limestone shales . . . 400 ,, 



