A Handbook of Northern France

er. The relation between the rock layers and the surface forms here occurring is moreover in many ways so manifest and so significant, that an understanding of it aids the memory in placing a multitude of details in their proper position with respect to the larger features of which they are parts. The Bordering Uplands and Highlands. The stratified formations occupying the Paris basin lie, with a total thickness of hundreds or thousands of meters, upon a foundation of ancient and disordered rocks which emerge in four upland or highland areas of unequal size around the basin borders as shown in Fig. 4: these are the Armorican area on the west, which includes the peninsula of Brittany and an adjoining part of the mainland, the extensive Central Highlands on the south, the Vosges (German, Vogeseri) of comparatively small area on the east, and the Ardennes with their eastern extension into the Slate-mountain highlands (German, Schiefer- gebirge) on the northeast. It is highly probable that the strata of the Paris basin, shown in section across the middle of Fig. 4, once overlapped the four areas of ancient foundation rocks much farther than they do now, and that they have been worn back because those areas are regions of upheaval; the Paris basin, on the other hand, is a region of relative depression, where the covering strata, broadly overspreading the disordered foundation rocks, have been preserved; the oldest members of the basin series crop out aro...