posted on 2016-06-21, 11:12authored byA. H. F. Robertson, O. Parlak, Y. Metİn, Ö. Vergİlİ, K. Tasli, N. İnan, H. Soycan
<p>Continental margin-type, ophiolitic and mélange units are exposed throughout central eastern Turkey (e.g. Gürün, Hekimhan
and Pınarbaşı areas). These restore as a north-verging Triassic-rifted continental margin that underwent Jurassic–Early Cretaceous
passive margin subsidence. Chemically ‘enriched’ basaltic lavas of seamount type are interbedded with and overlain by Middle
Jurassic–Early Cretaceous ribbon cherts. Ophiolitic rocks (e.g. Pınarbaşı, Dağlıca, Kuluncak, Hekimhan, Divriği) formed by
spreading above a Late Cretaceous northwards-dipping intra-oceanic subduction zone. Emplacement of continental margin units,
mélanges and ophiolites onto the East Tauride platform was driven by trench-margin collision during latest Cretaceous. The
northern part of the East Tauride neritic carbonate platform detached and overthrust the continent to the south (Malatya Metamorphics)
which was deeply underthrust, metamorphosed at least to greenschist facies and exhumed by latest Cretaceous. Collision-related
Mid-Eocene southwards thrusting strongly affected the western part of the region (e.g. Pınarbaşı), whereas areas further east
(e.g. Darende, Hekimhan, Divriği, Sivas) mainly experienced folding. Taking account of the regional tectonic setting, we infer
that the Gürün platform, with its distinctive unbroken up to Lutetian-aged succession, represents a small exotic terrane that
was translated from a relatively southerly (‘internal’) part of the Tauride platform (Geyik Dağ), related to strike-slip displacement
(syn/post-Eocene to pre-Pliocene).
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