202 PROF, BONNEY ON THE RELATION OF BRECCIAS [May 1go2, 
district, with a heavy rain- or snow-fall during part of the year,! 
possibly also with glaciers, and it bears a greater resemblance 
(though on a more limited scale and with fewer difficulties) to the 
beds ofthe Alpine Flysch, which I must now discuss in some detail. 
These, though agreeing in general character with the rest, except 
in the frequent presence of unusually large blocks, differ from them 
in being more commonly interbedded with fine-grained materials, 
and those of marine origin. Taking all the facts, already mentioned, 
into consideration, I see no escape from the conclusion, that late in the 
Kocene or at the beginning of the Oligocene Period, within afew miles 
—probably less than 10—was either amountain-range or an important 
highland district. Here the climatic conditions must have been favour 
able to the formation of breccias which must have been transported to 
the sea, by ‘ creeping’ or by rolling down the hill-sides, or by swollen 
torrents, after torrential rain or rapid melting of the snow. In 
either case we must assume the coast to have been slowly sinking, 
and in the former the breccias to have been deposited when an 
accumulation of silt had replaced the shallow sea at the foot of the 
hills by a flat alluvial plain. In the latter case we must suppose 
these floods to have occurred at rather irregular and long intervals, 
because the thickness of the intervening sediments is often con- 
siderable. The great size of some of the Habkeren boulders and 
the sporadic distribution of the débris are suggestive of transport by 
ice-rafts. This would relieve us of two difficulties,—one that the 
nearest crystalline rocks (in the Oberland) are about 12 miles 
away, which is rather too far for a breccia-fringe ; the other, that 
some of the most marked varieties of granite in the boulders 
cannot now be identified anywhere in the Alps. 
The Val-des-Ormonts breccias also present great difficulties. 
They require a more or less mountainous region, with considerable 
outcrops of crystalline rocks, besides others of Paleozoic or later 
ages ; but where is this to be placed? The increase in the thickness 
of the breccia-beds and in the angularity of their fragments, as 
they are followed towards the south-east, suggests that the land lay 
in that direction; but in the Western Oberland the older rocks 
appear to be buried beneath a considerable thickness of Cretaceous 
and Jurassic strata, with occasionally some Trias. In other words, 
the Mesozoic Era in this, as in other parts of the Alps, appears 
to have been one of steady subsidence, and its rocks (except at the 
beginning of the Trias) to be generally fine-grained. It is, of 
course, possible that the great earth-movements, of which the 
existing Alpine ranges are the results, had produced conspicuous 
effects before the close of the Eocene Period, but of this, so far as 
[ am aware, no proof can be found. The difficulty has been eluded 
hy assuming a mountain-range to have existed parallel with, and 
just north of, the present Alps, on a site now occupied by Nagelfluh 
or Molasse. But as this must have been high at the end of the 
Eocene, its disappearance (for it nowhere projects from the Miocene 
1 This appears also to resemble in some respects the ‘stone-rivers’ of the 
Falkland Isles. 
