Rev. J. Clifton Ward—Geology of the Isle of Man. 9 
While this state of things was interrupted in Cumbria by an 
outburst of volcanic violence, sub-marine eruptions passing into 
sub-aerial, we have no direct evidence to show that such was the 
case over the present area of the Isle of Man, though it is probable 
that some of the finer volcanic ash was, at any rate, occasionally 
wafted for many miles westwards. That. this area, in common with 
that of Cumbria, underwent elevation, accompanied by denudation, 
in post-Silurian and pre-Carboniferous times, is at any rate probable, 
and, as in Cumbria also, the early formed Carboniferous strata were 
deposited around a Silurian nucleus, the embryo Isle of Man. At 
this time, off the shores of that early Mona, submarine volcanic 
eruptions recurred, synchronous or approximately so with other 
like eruptions occurring farther northward over the present area of 
Scotland. There is no evidence of any such action taking place 
around the shores of the Cumbrian nucleus, although there are, 
south of Ullswater, masses of basalt which have broken into the 
Basement Conglomerate, and which may represent—as may also the 
Shap granite—abortive attempts of the Volcanic fires towards eating 
their way to the surface. Then in both areas we find the long 
unrepresented periods from Carboniferous to Glacial times, during 
which, after elevation at the close of or soon after the Carboniferous 
period, the mountain district of Cumbria and Mona’s Isle were 
respectively fretted by the denuding forces into their present form 
of hill and dale, under climates varying from semi-tropic warmth 
to glacial cold. As the cold of our last Glacial period, so called, 
reached its maximum, both districts were shrouded in ice-sheets, 
that of Cumbria self-born, that of Mona bearing down upon it most 
likely from a distance. Then followed a milder time and a sub- 
mergence to such an extent that in all probability Cumbria was 
represented by but a group of islands and Mona disappeared entirely 
beneath the waves. As the land in both areas once more appeared, 
glacial conditions returned to a considerable extent, and floating-ice 
laden with stones and boulders played its part in the cold drama, 
small bergs and floes being wafted first in one direction, then in 
another, as the currents changed with the varying amounts of 
elevated land. At length both the hilly areas of Cumbria and Mona 
stood up once more as of old, surrounded by a framework of low- 
lying land connecting the two districts, and allowing of the 
migration of fauna and flora from what by slight depression soon 
became the mainland, to the future independent Island of Man. 
Thus Mona is like a cast-off bud from Cumbria’s group of rocky 
mountains. 
EXPLANATION OF PLATE I. 
Fic. 1. Sketch-Map of the Isle of Man. 
», 2. Sketch-plan of Volcanic Rocks at, and west of Scarlet Point. 
» 8. Conglomerate resting unconformably upon Skiddaw Slate, and the two 
faulted against one another. West side of Langness. ‘The slate has 
been worn away leaving a natural arch of conglomerate. ‘ 
