VIII. On the fossil flora of the forest of Dean Coalfield (Gloucestershire), and the relationships of the Coalfields of the West of England and South Wales

Abstract

The Forest of Dean lies in a somewhat out-of-the-way corner of Gloucestershire, West of the Severn, and is bounded on the North-west by Herefordshire, and on the West and South by Monmouthshire and the Wye. The nearest coalfield is to the North, where a small area of Upper Carboniferous rocks occurs at Newent, also in Gloucestershire. The Bristol and Badstock coalfields lie some little distance to the South, and still further to the West is the great basin of South Wales. The Forest of Dean is remarkable for the simplicity of the structure of the Carboniferous area. As is well known, the basin is the most symmetrical in England, the beds, very little disturbed by faulting or folding, having, for the most part, a very regular outcrop. From the mining point of view, the entire absence of fire-damp and the consequent use of naked lights below ground, as is also the case in the Badstock coalfield, is remarkable. The Coal Measures, which occupy an area of about 16,700 acres, overlie beds which have long been spoken of as Millstone Grits, and these, with the Carboniferous Lime­-stone, form the elevated rim of the field, except for a short distance in the South-east, where the Coal Measures overstep both the so-called Millstone Grits and the Carboniferous Limestone (see p. 269). The latter has a much less regular distribution than the “Millstone Grits,” and a considerable development of the Limestone series is found to the North and West of the Forest, and this is continuous with a long tongue of Lower Carboniferous stretching South to Chepstow, and then South-west in the direction of Newport.