415 
[Foerste. 
i8 9 i.J 
arisen on the north side of the fold. At present, of course, this 
could not be the case since the land north of the fold lies at a 
considerably lower level than that at the highest part of the cross 
valley. This, however, is very likely due to subsequent more 
rapid erosion and degradation of the softer strata in the valley 
between the Monto and Moron folds, with their large drainage 
area, than along the Tavannes cirque , after it ceased to be occu- 
pied by a stream. 
The work accomplished by the Birse and Suxe and their tribu- 
taries seems tremendous and almost inconceivable if all the folds 
are supposed to have arisen simultaneously. It is probable, how- 
ever, that folding began along the southern margin of the Jura 
territory, and that folding was there already in progress while 
farther north the land as yet showed no signs of folding but re- 
tained its original southern slope. As these southern folds in- 
creased in size additional folds must have been successively 
added towards the north, and thus the southern cirques might 
have been in a fairly advanced stage of development before some 
of the more northern folds had even reached their incipient 
stages of formation. 
After the cirques had been formed, it may be inferred that the 
entire Bernese Jura area, with all its folds and valleys as mere 
surface features, was subjected to warping on a large scale, and 
thus the very broad and low anticline was formed which dis- 
turbed the general southward drainage at various points along 
the Jura folds, cutting off along its crest the headwaters of the 
southward flowing persistent streams, and inverting these head- 
waters into a northward flowing drainage system. In the case of 
the drainage here discussed, the Tavannes cirque must have lain 
near the crest of this low and comparatively recent anticline. 
14. Streams consequent on the Folding. Thus far, little atten- 
tion has been given to anv but the transverse streams of the 
cirques. The new drainage channels, whose directions w^ere de- 
termined by the new inclinations given by the processes of fold- 
ing, may now be considered. They will be here called initial 
consequent streams. Of these there are two kinds : longitudinal 
or synclinal streams, following the valleys between the folds, and 
lateral or cataclinal streams, running down the sides of the folds. 
The first are the chief valleys of the region ; the second are in- 
conspicuous. Both kinds are abundantly represented in the Jura 
