CHAP. XXXII 
ERUPTIVE ROCKS OF THE MIDLANDS 
IOI 
been stripped of it by denudation before the deposition of the Coal-measures. 
It seems much more probable that the discrepance in the terrestrial move- 
ments had commenced in Old Bed Sandstone time, and that these ridges 
of ancient Palaeozoic rocks never sank below the waters in which the vast 
thickness of red sandstones, marls and conglomerates was laid down. 1 
But apart from the question of its antiquity, this tract of persistent 
land has a special interest in the history of volcanic action in Britain, for it 
was the scene of some remarkable protrusions of eruptive material which 
took place after a part, and possibly after the whole, of the Coal-measures 
were accumulated. The date of these protrusions cannot be fixed with 
greater precision ; but there can be no doubt that they belong to one of the 
later volcanic periods in the geological history of Britain, and the account 
of them is therefore included in the present Chapter of this work. 
In the English Midlands south of Stafford, over a tract of country about 
700 square miles in extent, stretching from Birmingham on the east, across 
the vale of the Severn, to the uplands of Shropshire on the west, the Coal- 
measures, partly isolated into outliers by denudation and partly separated 
by overlying younger formations, are pierced by masses of intrusive igneous 
rocks. Many of these masses have long been familiar to geologists. Those, 
tor example, of the Clee Hills of Shropshire, and the Bowley, Barrow and 
Bouk Hills of Staffordshire and Worcestershire, have been frequently de- 
scribed, their relations to the surrounding strata have been minutely sought 
°ut, their composition has been chemically determined, and their microscopic 
structure has been investigated. But they have been studied rather as 
mdividual masses of local importance. Xo attempt has yet been made to 
ascertain how far they are capable of being grouped together as one con- 
nected series, linked with each other in chemical and mineralogical characters, 
and containing a definite record in the volcanic history of the country. 
This is a task which, it is to be hoped, some competent inquirer will before 
lo ng undertake. 
In the meantime it is only possible to review here the already published 
information, and to gather from it what may at present be surmised to have 
een the history of these later eruptions of the Midlands. 
I he areas where the igneous rocks now to be described are exhibited 
nuy h e conveniently placed in the following five groups: — 1st, Titterstone 
- eeHill; 2nd, Brown Clee Hill ; 3rd, The Forest of Wyre Coal-field ; 4th, 
e Coalbrookdale Coal-field ; and otli, The South Staffordshire Coal-field. 
1- The Titterstone Clee Hill forms a ridge about seven miles long and a 
ni e and a quarter broad, running in a north-easterly direction over the Old 
r s Sandstone uplands of the south of Shropshire. The ground rises gradu- 
^ towards the south-west, until it reaches there a height of 1754 feet 
g- -->2). On the north-western side of the ridge, the last vanishing 
lepresentative of the Carboniferous Limestone can be seen to be overlapped 
} I ic Millstone Grit, which, as it is traced towards the south-west, is in 
1,1 n ov eriapped by the Coal-measures, and these, about 400 feet thick, then 
kee a discussion of this subject in Jukes’ Preface to his South Staffordshire Cocd-ficld. 
