Cenozoic tectosedimentary evolution of Mallorca island

Abstract

The results of recent biostratigraphic, sedimentologic and structural work concerning the island of Mallorca have led us to elaborate a synthesis of the Cenozoic tectosedimentary evolution of this area. The recognition in the field of several unconformities enabled us to distinguish four Depositional Sequences embracing the pre and syntectonic deposits.From Paleocene to part of Middle Eocene there was no sedimentation in the Mallorca area. This stratigraphie gap follows the onset of Africa-Europe convergence.The area was stable during the first sequence (Upper Lutetian-Bartonian), which is trangressive towards the NW. Tectonic activity is recorded by the conglomeratic wedges of Depositional Sequence 11 (Priabonian-Lower Chattian). A dramatic paleogeographic change ocurred between Depositional Sequence II and III. Observed thrusts and unstable platform sediments of Depositional Sequence III (Upper Chattian-Lo-wermost Burdigalian) indicate the onset of thrust tectonics in the area. Turbiditic deposits of Depositional Sequence IV (Burdigalian-Langhian) are clearly syntectonic. Post-orogenic deposits range from Serravalian to recent and are not discussed in this paper.Synthetic regional geological cross-sections have been constructed. They are used to restore the cartographic structural units to their relative pre-tectonic position and a palinspastic map for each Depositional Sequence has been obtained. These maps show both the sedimentary environment distribution and the active tectonic structures; hence they illustrate the tectosedimentary evolution of the Mallorca area through the Cenozoic.This work has evident limitations arising from the small area studied in relation to the Cenozoic Betic basin and from the lacking subsurface data.