Evidencias de facies rojas remagnetizadas en el Atlas Medio(Marruecos)

Abstract

A paleomagnetic study has been carried out in the boundary between the Folded Middle Atlas and the Tabular Middle Atlas, around Skoura and Tig hboula synclines and Boulemane anticline. The goal of this work is to test the existence of a remagnetization affecting the sedimentary rocks in this area. For this purpose different stability tests were done: (i) two fold tests, one in the Boulemane anticline by studying five paleomagnetic sites located in Jurassic limestones, and the other in the Tighboula syncline in three sites from Cretaceous red-beds; (ii) a conglomerate test was done sampling a Cretaceous basal level and the overlying red-beds. The results of these tests show a synfolding remagnetization in the red-beds, whereas the magnetic signal of the limestones is too weak and it is not possible to isolate a magnetic component. Red-beds shows similar paleomagnetic properties than in other basins of the High Atlas (properties of the nat ural remanent magnetization, a probably NNW trend of the remagnetization and a systematic normal polarity), which could indicate a relationship between both.