Significance of Inherited Normal Faults during Inversion Tectonics:: an example from the Tramuntana Range, Mallorca

The Late Oligocene-Middle Miocene Mallorca fold-and-thrust belt is characterised by a large amount of shortening above a detachment horizon. A regional section of 50 kin in length across the island shows shortening of 80 km. Nevertheless, earlier normal faults play a significant role in compressive deformation. Two examples illustrating their role are presented: the first example is a fault-propagation-fold nucleated on a normal fault located in the fold core. We present a simple numerical model of this structure that illustrates how the observed complex structural and stratigraphic geometries might develop. The second example is a normal fault that interrupts the detachment level, giving rise to a step that results in a back-thrust system. (c) 2004 Lavoisier SAS. All rights reserved.