THE ANCIENT VOLCANOES OF DERBYSHIRE. 96 
voleanic activity in the British Islands, and the volcanoes which 
belched them forth probably died out long before the advent of that 
remarkable era known to us as the Glacial Epoch, and therefore 
immensely anterior to the appearance of man. 
The more ancient period referred to, viz., the Carboniferous, 
appears to have been ushered in and closed by volcanic outbursts, 
which must have been far more violent and extensive than any 
eruptions of modern times, Evidences of these are found all the 
world over, and it is to this epoch that the Volcanoes of Derbyshire 
are to be referred. 
Before proceeding to discuss these in detail, it would perhaps be 
well to give a little attention’ to the nature of ancient volcanic 
phenomena generally. 
The geologist observes the elevated land that once formed the 
bottom of an ancient sea, the raised beaches round the sea coasts, 
the slow subsidences of great land areas, the unfathomable faults, 
that, by dropping or rising, bring into proximity rock formations 
utterly different in character: the miner, by reason of these very 
faults,—often without the slightest indication of their presence on 
the surface, suddenly loses his bed of coal or metal-bearing vein, or 
a great wall of igneous rock may unexpectedly confront him, deep 
down in the mine, compelling the abandonment of the workings, or 
the expenditure of large sums in cutting through the unprofitable 
rock before the productive beds can again be reached, These phen- 
omena are observed everywhere, and Derbyshire geologists and 
miners have ample experience of them. Such conditions are indica- 
tions of the volcanic or seismic disturbances of past ages. 
The examination of a MODERN volcanic district shows much 
evidence of considerable rock fracture and dislocation: thick lava- 
flows, and beds of scorie and dust cover the country for miles around. 
Making due allowance for the changes produced by the agencies of 
