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denuded about a quarter of a mile North of Bream’s Lodge, 
where the Old Red Sandstone comes in, extending to Priors 
Meend and Aylburton Common, and is separated into two 
irregular branches. The South-Western portion extends to 
the North of Bream’s Lodge and St. Briavels, to Hewelsfield, 
towards Tintern, Chepstow, and Caerwent, where it occupies a 
considerable area, and continues still further to the South. 
The Eastern limit of the limestone nearly coincides with a line 
drawn from Bream’s Cross through Tidenham House, as far as 
Tidenham. The other portion of the limestone branches off 
near Bream, and follows the coal measures as a narrow regular 
strip about a quarter of a mile in width to a down throw fault 
at Lodge’s Kiln; it then extends a little further Southwards, 
and terminates at the place before referred to. 
The connection that once existed between Dean Forest 
and the Monmouthshire and South Wales coal fields was 
destroyed, and the intervening limestone and Millstone Grit 
measures were swept away, except in a few patches marking 
the ancient or continuity connections of the districts. 
The Old Red Sandstone entirely surrounds the Forest of 
Dean Mineral Basin, and upon it, as a base, the Carboniferous 
series repose. It may be traced to Lydney, Aylburton, 
Alvington, Woolaston, and Southwards to Tidenham, where it 
terminates against the New Red Marls on the East, Dolomitic 
Conglomerate on the South, and Carboniferous Limestone on 
the West. From Aylburton it runs Westward to the limestone 
for a distance of 24 miles; from Lydney it extends in an 
irregular manner to Nass Cliff, on the Severn where it spreads 
itself Northward and forms the left bank of the Severn for a 
distance of 3} miles, and is separated from the Lower Lias 
Clay and limestone by a fault. Taking a Northern course, the 
Old Red occupies a considerable area in Herefordshire, Mon- 
mouthshire, Brecknockshire, and surrounds the greater portion 
of the Glamorganshire coal field. On the Hast, the Old Red 
is bounded by a fault commencing at a point previously re- 
ferred to. 
D 
