252

Limestone lying under Gneiss , to thedepth of 200 feet, or alternating with Mica -slate and Clay-slate.

At Klostergrab \ in Bohemia, Gneiss rests upon Porphyry.

Beds of Hornblend , under different va-rieties, says Von Buch, appear to be sub-ordinate to all the primitive formations.

If we consult Herman on the Urals , VonBuch and Hausman on the NorwegianChain ; Brongniart on the Cotentin ;'Rau-mer on the Harz ; Heim on the Forest ofThuringia; Fichtel on the Carpathians ;Dolomieu on the Vosges; we shall find, ineach of these districts, anomalies no lessremarkable than those which have beenalready detailed. In America , the orderof succession, which the Wernerian theoryprescribes to the primitive rocks, is so oftenvaried and reversed, that Maclure b de-clares it impossible to arrange them in anyregular series.

Groscke c states, that the Grampians pre-* Voigt.

b Journal de Physique, vol. lxxii. p. 142.e Bergbaukunde, vol. i. § 309.