1911.] Fossil Flora of the Forest of Dean Coalfield, 545 



higher beds of the Carboniferous Limestone series, which here have an 

 arenaceous facies. True Millstone Grits, as well as Lower, Middle, and 

 Transition Coal Measures, are absent in the Forest of Dean. 



The relationships of this coalfield to the neighbouring coalfields of the 

 West of England and South Wales are discussed from the paleeobotanical 

 standpoint. It is found that the Forest of Dean basin exhibits no obvious, 

 relationship, either to the South Wales or to the Radstock-Bristol coalfields. 



The Pennant Grits of South Wales belong to a lower horizon than the 

 markedly arenaceous series (the " Forest of Dean stone ") of the third division 

 of the Forest. The Radstock-Bristol and Forest of Dean basins are believed 

 to be related tectonically, though not to the main axes of South Wales and 

 the Mendips, but to a secondary cognate uplift, stretching north and south, 

 and approximating to the valley of the Severn. On the other hand the 

 Forest of Dean does not appear to be related to the Welsh borderland series 

 of coalfields, stretching from JTewent to Shrewsbury. 



In the case of the Forest of Dean, it seems evident that the Lower 

 Carboniferous rocks and the Old Red Sandstones of the area remained 

 elevated above sea level, and were denuded until the beginning of Upper 

 Coal Measure times, whereas in South Wales depression and deposition set 

 in in Middle Coal Measure times, and in the Radstock-Bristol area during 

 the Transition Coal Measure period. Thus, on the palaeobotanical evidence, 

 the relationships of the coalfields of the West of England and South Wales 

 have proved to be more complex than has hitherto been supposed, and this 

 appears to be due in part at least to the coincidence of three distinct axes of 

 elevation in the neighbourhood of the Forest of Dean. 



