534 REPORT—1904. 
later every such period came to an end. Compression and upheaval took the 
place of subsidence, and the strata lately deposited were plicated and brought 
within the reach of denudation. [Illustrations of the recurrence of these move- 
ments abound, and I need dwell no further upon them than to remark that 
movements of subsidence and upheaval may be seen to have alternated wherever 
opportunity is afforded for observation. 
On extending our observations we are led to infer that the movements of the 
crust were developed regionally, not universally. The areas of subsidence, for 
example, evidenced by the marine formations, had their limits, though those limits 
did not coincide with the shores of existing seas, nor has reason been found to believe 
that the proportion of land to sea has varied greatly in past times. The limits of 
the area affected by any one movement of upheaval are more difficult to determine, 
but the effects were manifested in the crumpling up of comparatively narrow belts 
of country, and are easy of recognition. 
Further than this, we ascertain that the movements of one region were not 
necessarily contemporaneous with those of adjoining regions. The forces operat- 
ing upon the crust of the earth came into activity in different places at different 
times, and, while some continental tracts have been but little disturbed from early 
geological times, there are parts of the globe which have been the scene, so to 
speak, of almost ceaseless strife. Among the latter we may include the British 
Isles. 
These are commonplaces of Geology, and I mention them merely to emphasise 
the fact that the geological structure of these islands is the result of movement 
superimposed upon movement. Obviously, therefore, in order to gain a com- 
prehensive view of the operations which were in progress in any one region during 
any one epoch, we have to find some means of distinguishing the movements of 
that epoch and of eliminating all which preceded or followed it. This, briefly, is 
the problem which has engaged the attention of geologists for many years past, 
and upon which I propose to touch. 
The determination of the age of a disturbance is seldom easy, and among the 
older Paleozoic rocks is often impossible; but at the close of the Carboniferous 
period, during the great continental epoch which led to and followed upon the de- 
position of the Coal Measures, there came into action a set of movements of 
elevation and compression, which generally can be distinguished both from those 
which preceded them and from those which have been superimposed upon them. 
The distinction depends upon the determination of the age of the rocks affected by 
the movements. For example, a movement by which the latest Carboniferous rocks 
have been tilted from their original horizontal position is obviously post-Carboni- 
ferous. On the other hand, if Permian rocks lie undisturbed upon those tilted 
Carboniferous rocks it is equally obvious that the movement was pre-Permian. Now 
it happens that earth-movements of the date alluded to were particularly active in 
the British Isles, and played an important part in shaping the platform on which the 
Permian and later rocks were laid down. Though they have been more completely 
explored than others in the working of coal, their further investigation is of the 
greatest economic importance. I have attempted, therefore, briefly to sketch out the 
principal lines along which earth-movements of that age came into operation in 
England, premising, however, that by Permian I mean the Magnesian Limestone 
series, and not the ‘ Permian of Salopian type,’ which is now known to be partly 
of Triassic but principally of Carboniferous age. In the course of the investigation 
we shall find reason to conclude that several at least of the movements followed 
old axes of disturbance, lines of weakness dating from an early period in the 
history of the habitable globe; and, again, that some of the latest disturbances 
of which we have cognisance were but renewals of movement along the same 
general lines. 
One of the most clearly proved examples of pre-Permian faulting in the Car- 
boniferous rocks occurs in the Whitehaven Coalfield. The fault forms the south- 
eastern limit of the Coal Measures, and has been precisely located for a distance cf 
six miles. In its course towards the south-west it passes under five outliers of 
Permian rocks, and finally is lost to sight under the Permian and Trias of St. Bees. 
