Tectonophysics, 107 (1984) 25-56 25 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands PLATE AND INTRAPLATE PROCESSES OF HERCYNIAN EUROPE DURING THE LATE PALEOZOIC VOLKER LORENZ 1 and IAN A. NICHOLLS 2 i Institutfitr Geowissenschaften der Johannes Gutenberg-Universiti~t, Saarstr. 21, D-6500 Mainz ( West Germany) 2 Department of Earth Sciences, Monash University, Clayton, Vic. 3168 (Australia) (Received May 26, 1983; revised version accepted November 23, 1983) ABSTRACT Lorenz, V. and Nicholls, I.A., 1984. Plate and intraplate processes of Hercynian Europe during the Late Paleozoic. Tectonophysics, 107: 25-56. It is speculated that until Late Carboniferous time the region of Hercynian Europe was occupied by an elongated island arc system underlain by a segment of continental crust. In the Upper Carboniferous, two subduction zones are assumed to have extended from the north and south beneath Hercynian Europe. An extensive zone of hot, partially molten upper mantle lay above and between these, and diapiric uprise of portions of this material led to separation of mafic magmas, widespread partial melting in the lower and middle crust, high temperature-low pressure metamorphism in crustal rocks, and regional uplift and extension of the crust, as indicated by intermontane troughs and their associated volcanic rocks. In Visean to Westphalian time Hercynian Europe collided with both the large neighbouring plates North America-Europe and Africa. During these diachronous collisions and owing to reduced rigidity of the relatively hot island arc crust, the irregular continental margins of the larger and thicker continental plates induced oroclinal bending of Hercynian Europe. After the collision processes had been terminated. processes of upper mantle activity continued, causing further crustal uplift and even. enhanced crustal extension for several tens of million years into the Lower Permian. Decline of the upper mantle activity beneath Hercynian Europe is indicated by crustal subsidence and formation of a peneplain in Permian time followed by the Upper Permian transgression of both the Zechstein sea and the Tethys sea which mark the end of the Hercynian geodynamic cycle. INTRODUCTION The Hercynian mobile belt extends from the Caucasus through some twenty European countries into northwestern Africa (Fig. 1). The immense wealth of geological data accumulated of this classic region is distributed through many journals, and written in many languages, a situation which makes integration of existing knowledge difficult. In addition large areas of the belt are covered by younger rocks or have been reactivated during the Alpine tectonic cycle. 0040-1951/84/$03.00 © 1984 Elsevier Science Publishers B.V.