Page:The Journal of geology (IA journalofgeology11893univ).pdf/222

Two classes of implements were found; those of argillite and those of jasper and quartz. He concludes that "an argillite-using man wandered far and wide over this country long before the use of jasper and quartz became so universal." The older "fairly well specialized argillitic implements" are, in some localities, found in places at higher levels than the jasper and quartz implements, being deposited when the river flowed at higher levels than at present. However, by erosion and weathering, many of the argillite implements have been dislodged and mingled with the jasper implements along the course of the present river. The subject of palæolithic implements in the undisturbed Trenton gravels is not discussed. The burial customs, earth works, stone mounds, village sites and jasper quarries of the later inhabitants of the valley receive consideration.

The geological history of the Bernese Jura consists of a series of elevations and depressions, from the Triassic up to the time of the folding in late Tertiary time. The folds have a general east-northeast trend, and were formed by pressure exerted from the southeast along the whole line of the Jura folds. The folds are the strongest along the southeastern border, and decrease in altitude northwestward. They have been considerably eroded. Tertiary and Cretaceous strata are removed from the crests and upper flanks of the higher folds. The drainage lines are: (1) Longitudinal synclinal valleys; (2) Occasional shallow longitudinal valleys along the crests of the anticlines, and (3) Transverse valleys across the folds. The origin of these transverse valleys, particularly those of the Suxe and the Birse, is the question especially discussed. 1. The absence of faults at the points where the valleys cross the folds is fatal to the theory of their origin through faults, as held by Thurman. 2. Their origin from fractures, as held by Studer, Jaccard, Reutimeyer and Greppin, is improbable, for the fractures are not frequent in the Jura mountains now. That every gap due to fracture should have become a transverse connecting water channel is improbable. Some would have remained as wind gaps. 3. That they did not originate from outlets of lakes, as suggested by Phillipson, and Noe and Margerie, is manifest from the fact (1) That there were lower points by which the lakes could have drained; (2) Some of the basins made by the folding have more than one valley cutting through the fold enclosing them. 4. The inconspicuous part played by the lateral streams on the sides of the Jura Mountains is unfavorable to the