Paleomagnetism as a structural polarity criterion: application to Tunisiandiapirs

In the Upper Aptian-Albian units, close to Triassic displaced bodies of nor thwestern Tunisia, the primary magnetization acquired during the Cretaceous period of normal magnetic polarity yields an unquestionable structural pol arity criterion. The use of this criterion confirms the diapiric origin of these Triassic bodies and aids understanding of the evolution of the diapir s. It also appears to be a useful tool for the analysis of the geometry of overturning. An Eocene halokinesis on the platform south of the Tunisian Ch annel is also indicated by analysis of magnetic overprint in the Jebel Slat a. (C) 2000 Elsevier Science Ltd. All rights reserved.