Tectonic-sedimentary evolution of the northern margin of Gondwana during Late Palaeozoic – Early Cenozoic time in the Eastern Mediterranean region: evidence from the Central Taurus Mountains, Turkey.

摘要

The Taurus Mountains are an E-W trending mountain range in southern Turkey, with anudelevation of up to 3500 m. In the south central Taurides, the Beysehir-Hoyran-Hadimudnappes, a series of thrust sheets of Palaeozoic to Early Cenozoic age, are emplaced ontouda relatively autochthonous Tauride platform, known as the Geyik Dag. These thrustudsheets consist of a variety of discrete tectonostratigraphic units of continental platform,udrifted margin and oceanic (ophiolitic) origin. It is generally accepted that the relativelyudautochthonous Tauride platform and the associated thrust sheets restore as a north-facingudpassive margin during Jurassic–Cretaceous time; however, the Triassic and earlierudtectonic setting of the Tauride units is contentious. New data (mainly structural andudsedimentological) presented here tests contrasting tectonic models of Late Palaeozoic –udEarly Mesozoic Tethys ocean evolution. Also, new light is shed on the Late Cretaceousudand Early Cenozoic break-up and emplacement of the Tauride units during closure ofudTethys.udThe Late Palaeozoic Tauride stratigraphy consists of shallow-marine carbonate,udsandstone and mudstone, characteristic of a proximal passive margin. Detailedudstratigraphic logging, facies interpretation, compositional analysis and geochemicaludevidence supports a passive margin setting, with sediment derived from the Taurideud“basement”. Early – Middle Triassic mixed siliciclastic/carbonate sediments areudinterpreted as representing rifting and subsidence. Late Triassic coarser terrestrialudclastics (Cayir Formation) are considered to represent a pulse of rift-related flexuraluduplift. Sediment provenance during this time was from the underlying Tauride platformudto the north of the studied area. A previous hypothesis that a Palaeotethyan ocean closedudin this area during latest Triassic “Cimmerian” orogenesis is discounted. Instead,udstructural and sedimentary data suggest that all of the deformation relates to LateudCretaceous – Early Cenozoic southward emplacement of the Beysehir-Hoyran-Hadimudnappes. A first phase of thrusting (thin-skinned) emplaced ophiolite and distal marginudunits, whilst a second phase (thick-skinned) thrust platform lithologies southwards ontoudthe foreland. Evidence is also summarised, notably from the Palaeozoic – EarlyudMesozoic Konya Complex to the north, which illustrates the relation of the Taurideudplatform to other geological terranes in Turkey and elsewhere in the Alpine-Himalayanudorogenic belt. This thesis increases understanding of large-scale tectonic andudsedimentary processes associated with continental margins and orogenic development.