La Desirade island (Guadeloupe, French West Indies): a key target for deciphering the role of reactivated tectonic structures in Lesser Antilles arc building

In this paper we present and discuss new investigations performed on both the magmatic basement and the sedimentary formations of La Desirade. We report structural and sedimentary evidences for several episodes of deformation and displacement occurring prior to the present day tectonics. The main faults, respectively N130 +/- 10 degrees, N040 +/- 10 degrees and N090 +/- 10 degrees, previously considered as marker of the current tectonic regime corresponds to reactivated tectonic structures developed first during late Cretaceous compression and second during Pliocene to early Pleistocene extension. We demonstrate also the importance of late Pliocene-early Pleistocene and middle-late Pleistocene vertical movements in this part of the Lesser Antilles fore-arc as well as the role of compressive tectonics in the over thickened character of the arc basement in the Guadeloupe archipelago.