39 Subduction, collision and orogeny. Part 2

Thursday, 7 October 2010
2:30 PM - 4:50 PM
Kemal Kurdas Salon

HOW MANY SUBDUCTION ZONES AND OCEANS, POST-CRETACEOUS EVOLUTION OF TURKEY: INFERENCES FROM MANTLE TOMOGRAPHY

Paper number: 39-5
Program: Scientific Sessions
Time: 3:50 PM – 4:10 PM

Authors

Abstract

The early Mesozoic evolution of Turkey is related to the opening and subduction of strands of the Neotethys ocean and its closure during since the late Cretaceous. Various opening and closing scenarios have been proposed for the region, involving multiple oceanic basins and multiple subduction zones, in many different configurations. These scenarios were based mainly on surface geological and potential field data, and whereas only limited seismic tomographic images are available to test them.

Positive seismic wave-speed anomalies related to lower temperatures in the mantle are normally correlated with subducted slabs, and can be used to identify slabs and other remnants of lithosphere in the mantle. Available high-resolution mantle tomographic images around Turkey from Black Sea to Eastern Mediterranean region do not support multiple simultaneous subduction zone scenarios. Subducted slabs in the region are either still attached to the present oceanic crusts, or are detached form continuous coherent anomalies at depths of more than 1200 km.

In this contribution, we discuss the feasibility of various subduction scenarios proposed previously based on published mantle tomography and geological information, as well as new seismic tomographic images.