Original paper

The Scandinavian Caledonides and the Western Carpathians: a comparative study of two orogens

Greiling, Reinhard O.

Abstract

The aim of this study is compare two orogens of different age, which developedtypical marginal fold-and-thrustbelts in the course of collision of exotic terranes with different margins of the North/East European plate. The Carpathians show a narrow pre- orogenic passive margin with relatively thick sedimentary sequences. The detachment horizon at the base of the orogenic wedge is situated within the sedimentary sequence. Propagation of nappes over the foreland lithosphere was broadly continuous and was preceded by sedimentation of thick, syn-orogenic clastic sequences. In the Caledonides, a thin sedimentary sequence rests upon a wide passive margin. The base of the orogenic wedge is at or only slightly above the basement-cover surface. Several tectonic events during convergenceare separatedby relatively quiet periods. Major nappes developed only during the final stages of collision. One ofthe causes for the differences is the strength of the lithosphere. Astrong lithosphere in Scandinavia caused a wide and shallow foreland basin, a relatively weak lithosphere in the Outer Carpathiansled to a deeper and narrower forelandbasin.