The kinematics of central-southern Turkey and northwest Syria revisited
Résumé
Central-southern Turkey, NW Syria, and adjacent offshore areas in the NE Mediterranean region form the bound-ary zone between the Turkish, African and Arabian plates. A great deal of new information has emerged in recent years regarding senses and rates of active crustal deformation in this region, but this material has not hitherto been well integrated, so the interpretations of key localities by different teams remain contradictory. We have reviewed and synthesised this evidence, combining it with new investigations targeted at key areas of uncertain-ty. This work has led to the inference of previously unrecognised active faults and has clarified the roles of other structures within the framework of plate motions provided by GPS studies. Roughly one third of the relative mo-tion between the Turkish and Arabian plates is accommodated on the Misis–Kyrenia Fault Zone, which links to the study region from the Kyrenia mountain range of northern Cyprus. Much of this motion passes NNE then eastward around the northern limit of the Amanos Mountains, as previously thought, but some of it splays north-eastward to link into newly-recognised normal faulting within the Amanos Mountains. The remaining two thirds of the relative motion is accommodated along the Karasu Valley; some of this component steps leftward across the Amik Basin before passing southward onto the northern Dead Sea Fault Zone (DSFZ) but much of it continues southwestward, past the city of Antakya, then into offshore structures, ultimately linking to the subduction zone bounding the Turkish and African plates to the southwest of Cyprus. However, some of this offshore motion con-tinues southward, west of the Syrian coast, before linking onshore into the southern DSFZ; this component of the relative motion is indeed the main reason why the slip rate on the northern DSFZ, measured geodetically, is so much lower than that on its southern counterpart. In some parts of this region, notably in the Karasu Valley, it is now clear how the expected relative plate motion has been accommodated on active faults during much of the Quaternary: rather than constant slip rates on individual faults, quite complex changes in the partitioning of this motion on timescales of hundreds of thousands of years are indicated. However, in other parts of the re-gion it remains unclear whether additional major active faults remain unrecognised or whether significant rela-tive motions are accommodated by distributed deformation or on the many smaller-scale structures present.
Domaines
Tectonique
Origine : Fichiers produits par l'(les) auteur(s)
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