FRE-CARBONIFEROUS FLOOR OF THE MIDLANDS. 
101 
The overlying beds include the Barr or Hay Head 
(Woolliope) limestone; then 800ft. of Wenlock shales (well 
shown in the railway cuttings) ; and lastly, at Dun End and 
Walsall Town, the two bands of the Dudley ( = Wenlock) 
limestone; these being immediately overlaid by coal- 
measures, the whole series of rocks dipping westerly. 
6. —The Silurians of Dudley and Sedgley. —Crossing now 
to the western boundary of the South Staffordshire Coalfield, 
we find that also formed by a fault, which has again brought 
Silurian rocks to the surface. But as the throw of this fault 
is somewhat less than that of the eastern boundary, we here, 
at Sedgley, find the lowest rock exposed to be the Wenlock 
Shales. Above these come the two bands of Dudley 
( = Wenlock) limestone, then a great thickness, perhaps 
1,000 feet, of Ludlow Shales, near the top of which we 
find the Sedgley ( = Aymestry) limestone. Although the 
beds undulate, their yeneral dip is to the east. 
A little south of the Sedgley area the Silurian rocks again 
rise to the surface in the two dome-like masses of the Wren’s 
Nest and Dudley Castle ; here we get the Wenlock shales 
and limestone only. A little farther south there is a small 
exposure of the same beds at the Lye. Thus far we are able 
to see a strong resemblance between the structure of the South 
Staffordshire and the Warwickshire Coalfields. Each is 
bounded on the east and on the west by faults which run north 
and south, and by which the rocks lying beneath the coal 
measures are brought to the surface. The differences, how¬ 
ever, are considerable. In Warwickshire the boundary line is 
a double fault, and the rocks brought up are Cambrians, while in 
Staffordshire they are Silurians. The coal-seams of Warwick¬ 
shire, moreover, increase in depth from the surface, and pass 
beneath newer rocks as we follow them southward, and the 
southern boundary of that coalfield is unknown. But in 
Staffordshire just the opposite happens ; we know that the 
coals there terminate in a southerly direction against a buried 
ridge of Silurian rocks, the actual outcrop of the seams being 
hidden by the upper coal measures which overlap. But a little 
further south these old Silurian rocks, and others of still 
greater antiquity, are brought to the surface in a manner 
which strongly reminds us of the Hartshill region. 
7. — The Lower Lickey Hills. —The Lower Lickey Hills form 
part of the southern boundary of the South Staffordshire 
Coalfield. They consist of a low camel-backed ridge, some 
500 feet in height, running from north-west to south-east for 
between two and three miles. Access is easy from the Barnt 
Green Station (at the southern end of the ridge), on the 
