270 MIDLAND UNION OF NATURAL HISTORY SOCIETIES. Dec., 1891. 
the great ring of the Oolite and Lias, rising np into the 
heights of Edgeliill, the Cotswolds, &c. Away to the north¬ 
west of the town there were the Longmynds and the Wrekin, 
and to the southward the jagged peaks of the Malverns, 
which were among the most interesting hills in Britain, 
for thev were formed of those Archaean rocks of which 
•/ 
we, as yet, know almost nothing. When they looked at 
any geological map of England they would see stretching 
from Hartlepool on the north-east and Blackpool on the 
north-west, far away to the south, a great band of Bed rocks. 
These rocks attained a breadth in the Midlands of forty 
or fifty miles from Leicester to Shrewsbury. Bising out in 
patches through this band of rocks they found the 
carboniferous or coal measures ; and these two measures—the 
red rocks and the coal rocks—made up the main features of 
the Midland area. He might compare them to two blankets— 
a red blanket above and a black blanket below ; but the black 
blanket only showed through where time and weather had 
worn holes in the red blanket above. Now these two sheets ot 
rock were once covered up by others, the Oolite and the Lias, 
but both these had long been swept away in that district. Above 
these lay, in former times, the great sheet of the Chalk, which 
once spread from this country as far as Ireland on the 
west; and over the Chalk again came the blanket of the 
Tertiaries. The red rocks already spoken of, which fol¬ 
lowed the coal measures were divided into two, the 
Permian below and the Trias above. This last was 
of different thicknesses, varying from about 4,000 feet in 
Cheshire to less than 750 feet at Leicester and Nuneaton; 
and consequently in this easterly direction only 700 feet or so 
had to be passed before the underlying coal measures were 
reached. Geologists believed that the Trias was laid down in 
a desert like the Sahara, or in a saline plain like that around 
the Caspian Sea ; and they would observe that there were salt 
basins which were naturally accounted for on this theory in 
our Bed Bock formation, as at Droitwich in Worcestershire, 
and Nantwich and other places in Cheshire. ThePermians, 
which came underneath the Trias, were at once of great interest 
and of great difficulty to Midland geologists. They were 
known to be older than the Triassic formations, because they 
were below them ; but geologists had been very uncertain 
how they were related to the Coal measures on which they in 
turn reposed, for if they followed the coal in regular successive 
order, then wherever the Permians existed in force there 
were 2,000ft. or 3,000ft. to be pierced before the carboniferous 
measures were reached. On the other hand, if they rested 
on the edges of the coal measures unconformably, the ease 
