Paleomagnetic Data Bearing on the Origin of the Supra- Subduction Zone Ophiolites in Southeast Anatolia and the Progressive Closure of the Neotethys Ocean in the Eastern Mediterranean

Abstract

The Late Cretaceous supra-subduction zone (SSZ) ophiolites in SE Anatolia form two parallel belts: the northern ophiolitic belt, which was emplaced onto the Tauride platform and a second southern belt emplaced on the Arabian platform. There are controversial hypotheses about the geometry and tectonic process of these ophiolites, which are still not well understood. Here, we test three alternative tectonic models for; (a) One single ocean which is defined by the & Idot;zmir-Ankara-Erzincan Ocean; (b) A southern branch of the Neotethys Ocean; (c) Two separate oceanic basins, which are the Berit Ocean and the South Neotethys Ocean. We present paleomagnetic results from 161 sites focusing on the sheeted dyke complex, cumulate gabbros, extrusive and sedimentary sequences of the Upper Cretaceous ophiolites in the SE Anatolian region. We also sampled the unconformable cover units from Middle Eocene and Miocene sedimentary rocks to distinguish emplacement related tectonic rotations from post-emplacement tectonic rotations. Our data indicate that the southern ophiolites (Hatay ophiolite, cumulate gabbro + lava) were formed at a paleolatitude of 21.4 degrees N-2.94+3.28 $21.4{}<^>{\circ}{\mathrm{N}}_{-2.94}<^>{+3.28}$ and those of the northern ophiolites (G & ouml;ksun, & Idot;spendere, Guleman ophiolite, cumulate gabbro + lava) were formed at a paleolatitude of 17.0 degrees N-2.81+3.06 $17.0{}<^>{\circ}{\mathrm{N}}_{-2.81}<^>{+3.06}$. We hypothesize that the northern ophiolites were derived from the Ocean in a NW-SE directed subduction zone between the Taurides and the Bitlis P & uuml;t & uuml;rge massif, while the southern ophiolites, in contrast, were formed in the South Neotethys Ocean in a NNW-SSE directed subduction zone farther northeast of the Taurides. Both the ophiolites reached their present position during Late Cretaceous to Middle Miocene, affected by rigid-block rotations almost in counterclockwise sense.