TRANSACTIONS OF SECTION C. 541 
small part of the globe, we have found reason to conclude that they were the 
result of compression and upheaval; that the crust yielded to the compression by 
overthrusting and buckling along certain belts; that these belts in the North of 
England and the Midlands ran for the most part north and south, diverging, how- 
ever, to the south-west and to the south-east, while in the South of England they 
took an east and west direction and concentrated themselves along a belt of country 
which presents the phenomena of crushing on a stupendous scale. We have 
onshed in two cases the flanks of a mountain-range—the Caledonian, which was 
built and ruined before the Carboniferous period ; the Armorican, which was built 
after that period, and which, though it has stirred so recently as the late Tertiary 
period, and so energetically as to initiate the physical features and river-system of 
the South of England, yet expended the greater part of its energy before the 
Permian period. Lastly, we have found evidence, in the majority of cases, that 
the disturbances were but renewals of movement along lines of weakness long 
before established, and that in several cases there has been further renewal along 
the same lines during successive periods later than the one we have considered. 
With such a history before us, and with the knowledge that mountain-ranges have 
been built in other parts of the world by the upheaval of strata of almost recent 
date, we have more cause to wonder that the internal forces have left this quarter 
of the globe alone for so long, than reason to believe that they have ceased to 
exist. Changes of level, however, have taken place in comparatively recent times, 
and are now in progress. Though almost imperceptibly slow, they serve to remind 
us that a giant lies sleeping under our feet who has stretched his limbs in the 
past, and will stretch them again in the future. Nor in view of the fact that the 
structures I have described have only been revealed by the denudation of vast 
masses of strata does it seem unreasonable to suppose that they are deep-seated 
phenomena. The slow changes of level may be the outward manifestation of more 
complicated movements being in progress at a depth. 
It is interesting to speculate on what appearance the globe would have presented 
had it not been enveloped in an atmosphere and covered for the most part with 
water. Owing to those circumstances it possesses the power of healing old wounds 
and burying old scars. In their absence we may suppose that the belts of 
crushing and buckling would have given rise to ridges growing in size at every 
renewal of movement, for they would have been neither levelled by denudation 
nor smoothed over by sedimentation. This globe, we may suppose, would have 
appeared to the inhabitants of another planet as being encompassed in a network, 
and we are prompted to ask whether our astronomers can distinguish in any other 
planet markings that may be attributable to this cause. I must remind you, 
however, how much more remains to be done than J have been able to touch upon 
to-day. The map represents one episode only in a long series of events, and a 
series of such maps would be required to illustrate the first appearance of lines of 
weakness in the earth’s crust, the subsequent renewals of movement along those 
lines, and the formation of new lines in successive geological periods. With the 
case thus set out we shall be justified in appealing to the physicists for an 
- explanation of the restlessness of this globe. 
The following Papers and Report were read :— 
1, The Geology of Cambridgeshire. By J. E. Marr, Sc.D., 7.RB.S. 
The main physical features of the county are the Chalk uplands of the south- 
eastern and southern part, the curious plateau on the west, the Cam Valley 
between them, and the fenland of the north. 
Of Jurassic rocks, the Oxford Clay is not well exposed save near Whittlesea. 
The Corallian rocks are of considerable interest. Two types occur—the Ampthill 
Clay facies of the western outcrop and the Calcareous facies of the Upware Inlier. 
The Elsworth rock forms the base of the deposits of each of these types, and its 
relationship to the members of the Calcareous facies is a subject still under discus- 
