Page:The origin of continents and oceans - Wegener, tr. Skerl - 1924.djvu/133

Rh On the other hand, the Permian of Timor only contains individual corals, and not those forming reefs in warm waters.

According to Gerth, the Permian of Uruguay and Southern Brazil shows a rapid increase of temperature. Mesosaurus already appeared there, and limestone and dolomite beds are found among shales, a fact which always denotes warm water. The Permo-Carboniferous “Red Beds” in western North America fit extraordinarily well in our picture, since they manifestly belong to the desert region of the northern arid zone. That great parts of Africa changed in the period from the Carboniferous to the Permian from the zone of temperate rains into the southern arid zone harmonizes very well with the conclusion of Passarge, who assumed a long desert period in the Mesozoic in order to explain the present-day surface features of that area.

Let us throw a glance for comparison on the distribution of climate in the Devonian period preceding the Carboniferous, but bear in mind the inexactitude of the groundwork of our maps, caused by the Carboniferous mountain folds not being smoothed out. It has already been mentioned that Lower Devonian traces of ice-action are known from South Africa. On the other hand, traces of the northern desert zone are seen in the Old Red desert formation, (already considered in, dealing with the geological arguments), in North America, Greenland, Spitsbergen and Northern Europe, and which also contains salt and gypsum deposits in North America and the Baltic Provinces. Thus it proves itself a good witness of the presence of the arid zone. The equator of the Lower Devonian must have had a similar orientation to that of the Upper