lod 
PRESIDENT’S ADDRESS—SECTION C. TL 
Then came the main uplift, with folding of the rocks, and the 
Pyrenees were formed. Slight depression occurred in the Miocene, 
with upheaval at its close, the miocene beds being contorted in 
the Lower Pyrenean Range at Corbiéres, but not elsewhere. 
These are overlain uncomformably by horizontal pliocene beds. 
Our first knowledge of Sz/7¢zerland is that during Permian 
and early Triassic times volcanic outbursts took place, followed 
by subsidence and deposition during the whole of the Mesozoic 
and early Eocene periods. This subsidence was not continuous, 
for, during the Mesozoic era, there were several oscillations in 
level, but without contortion. The deposits have a thickness of 
more than 30,000 feet, and include several masses of limestone 
over a thousand feet thick, which are thought to be old coral 
reefs. Upheaval, with plication, commenced towards the close 
of the Eocene. In the Miocene a great mountain range existed, 
with shallow seas both north and south of it. Subsidence again 
took place, and deposits of sandstone and conglomerate accumu- 
lated on the north side to a thickness of about 9000 feet. Then 
came a second elevation of more than 5000 feet, with folding 
during the Pliocene period, and sub-alpine Switzerland was 
formed. This latter folding was not equal all round, but greatest 
in the northern and central parts, the southern side being but 
little affected. At the same time the Jura mountains were 
raised. The rocks here are not contorted, but thrown into 
great folds, steep on the Swiss side and decreasing towards the 
French side, indicating that the thrust came from Switzerland. 
For the most part the synclinal folds form valleys and the anti- 
clinals form hills which must have risen up as surface swellings 
from the ground ; and these swellings are supposed to have risen 
so rapidly that they diverted the course of the Rhine and turned 
it northward. Volcanic action, both north and south of Switzer- 
land, commenced in the Miocene and declined in the Pliocene, 
but there are no volcanoes in the mountain range itself. 
The structure of the Himalaya Mountains is not so well known 
as that of the Alps, but they contain a conformable series from 
the Palozoic to the Cretaceous inclusive, indicating slow subsi- 
dence and sedimentation. At the close of the Cretaceous period 
elevation without contortion took place, accompanied by denu- 
dation so extensive as to lay bare in places the paleozoic rocks. 
At the same time the Deccan was flooded by enormous outflows 
of basalt, which cover more than 200,000 sauare miles, and reach 
occasionally a thickness of 6000 feet. Subsidence of the Hima- 
layan region again took place, with the deposition of eocene beds 
3000 to 5000 feet thick. Elevation with contortion followed, 
and the central range of the Himalaya was formed. The rise, 
however, was sufficiently slow to allow the Indus to retain its old 
channel and cut a path through the new mountains. Extensive 
denudation then occurred; valleys were carved out, and the 
