194 
PRE-CARBONIFEROUS FLOOR OF THE MIDLANDS. 
THE PRE-CARBONIFEROUS FLOOR OF THE 
MIDLANDS. 
BiT W. JEROME HARRISON, F.G.S. 
(Continued from page 167.) 
The Bunter Conglomerate .—This great accumulation of 
more or less rounded blocks of rock can be traced across the 
North Midlands from Worcester, by Bridgnorth, Stourbridge, 
Cannock Chase, Sutton Park, and Lichfield, to near Aslibourn 
and Derby. In a north-easterly direction it becomes a pebbly 
sandstone at Nottingham and in Sherwood Forest; but 
further north, near Selby, the pebbles disappear altogether, 
and in the borings through the Trias at Scarle, and near 
Middlesbro’, none were met with. The same change takes 
place in the west, for the pebbles in the Bunter round Liver¬ 
pool are small and few, while in the Carlisle district the lower 
Trias is not represented at all. In any case its only possible 
representative— the Kirklinton sandstone *—is quite devoid 
of pebbles. 
The base of the Bunter Conglomerate is a breccia, sixty 
feet thick near Kidderminster, and well exposed at Bridg¬ 
north and Kinver Edge. It consists of more or less angular 
fragments of grits, quartz, quartzite, sandstone, slate, and 
limestone. Above this we find from 100 to 300 feet of 
well-rounded pebbles, principally quartzites, although speci¬ 
mens of vein-quartz, chert, hard sandstones, mountain 
limestone, and traps and ashes, are present. Owing to the 
earth-movements in which the bed, as a whole, has taken 
part, the pebbles have been crushed against one another, so 
that they bear indentations which appear as white spots upon 
their surfaces. By the action of surface agents—principally 
ice during the last glacial period—immense numbers of the 
Bunter pebbles have been carried southward from the outcrop, 
and can be traced as far as the brow of the Thames vallev. 
The Trias has generally been regarded as an uninteresting 
set of rocks, owing to the almost total absence of fossils in its 
red marls and sandstones. This paucity of traces of life is 
usually assigned to the mode of its formation—deposited in a 
salt lake or lakes comparable with the Dead Sea or Lake 
Utah at the present day. But the pebbles of the Bunter 
contain numerous fossils, and if we are ever to know much 
of the source and mode of formation of this very remarkable 
and interesting conglomerate it must be by a close study of 
* See T. Y. Holmes, Q.J.G.S., Yol. XXXVII., p. 286. 
