Plate Tectonics and the Hercynian Orogeny

Abstract

NICOLAS¹ has proposed that the Hercynian Orogeny in Europe was of Andean type. He assumes the presence of a Tethyan Ocean separating Southern Europe from Africa in the Palaeozoic, and in his reconstruction Africa and Europe are already affixed to North America. There is, however, no evidence for the existence of a Tethyan Ocean in the Palaeozoic but there is evidence² that Africa did not collide with North America until well into the Carboniferous. Moreover, there are good reasons to suggest contiguity of Southern Europe and Africa throughout the Palaeozoic^3,4. On the other hand, there is good faunal evidence for the existence of a Mid-European Ocean separating Northern from Southern Europe in the Ordovician (ref. 5 and Burrett, in preparation) and in the Devonian⁶. In Silurian deposits typically Gondwanaland trilobites such as Burmeisteria are found to the south of this ocean and the giant Monograptus is found in Morocco, the Pyrenees and Sardinia⁷. It is suggested that this Mid-European Ocean contracted during the Devonian and Carboniferous (Figs. 1 and 2) causing the collision of Northern Europe with Southern Europe and the climactic Asturic deformation in the post-Westphalian.