478 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



occupies a prominent step on the sides of the plateau, and 

 standing out high above the surrounding gneiss, is in its 

 turn covered by black schists, through which basaltic trap 

 has pierced, occupying only a small upper portion of the central 

 part of the tract. In descending from this summit we were much 

 struck with the perfect symmetry of the Lower Silurian beds. 

 To the north, or on the side of the Wettern lake, the crys- 

 talline and gneissose rocks being in a depression, the fucoid sand- 

 stone ranges down to the water edge, surmounted by the alum- 

 slates, but on the south-eastern face of the hill of Kinnekulle the 

 gneiss is again seen to present exactly the same inferior relations 

 to the lower sandstone as on the western side, and the Orthoceratite 

 limestone is there strikingly developed by extensive quarries, 

 which form the first great step-like terrace between the basalt- 

 capped schists above and the low country of gneiss beneath. 

 Descending from these limestones, and passing over beds of alum- 

 slate and black limestone, the fucoid sandstone is seen in horizontal 

 masses, perfectly conformable to all the overlying strata, and 

 distinctly superposed to the gneiss below ; and indeed although the 

 absolute junction of the sandstone and gneiss is not seen, the two 

 rocks are within a hundred paces of each other, and without the 

 slightest indication of any other substance between them. The 

 gneiss also here is not merely in a lower position than the con- 

 tiguous sandstone, but, besides its crystalline structure, is at once 

 seen to belong to rocks of an entirely different class, and to be 

 quite independent of the overlying Silurian formation, so that the 

 one must have assumed its direction and structure before the other 

 was accumulated. 



It appears therefore that the gneiss, including many varieties, 

 must be considered the fundamental rock of Sweden, which 

 existed and was even highly inclined before the very lowest 

 Silurian beds began to be formed. 



If however, after examining the section of Kinnekulle, there 

 could be any doubt on this point, it would be dispelled by what 

 appears in other localities, where the lowest of the Silurian strata 

 are not only absolutely superimposed on the granitic gneiss, but are 

 proved to have been derived from it, and are composed of its very 

 materials. Examples of this phenomenon may be seen at Lugnos, 

 near the northern end of the Billingen Hills, where the Lower 

 Silurian beds (as at Kinnekulle), being deprived of their cover of 

 basalt, which has protected them from denudation over a consider- 

 able area to the south, are worn down, so as only to exhibit their 

 lowest portion, the alum-slate being partially visible above the 

 slopes of the rising ground, and the fucoid sandstone lying 

 beneath it. 



Here, at least, there can be no ambiguity ; for the whole of the 

 adjacent low tract is composed of rolling hillocks of granite 

 or granitic gneiss, which assume exactly that appearance of bell- 

 shaped masses so happily illustrated by M. von Buch. 



Again, in exploring the eastern shore of the great "Wettern Lake, 



