Testing models of Late Palaeozoic Early Mesozoic orogeny in Western Turkey: support for an evolving open-Tethys model

Robertson A., Ustaomer T., Pickett E. A., Collins A. S., Andrew T., Dixon J. E.

JOURNAL OF THE GEOLOGICAL SOCIETY, vol.161, pp.501-511, 2004 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 161
  • Publication Date: 2004
  • Doi Number: 10.1144/0016-764903-080
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.501-511
  • Istanbul University Affiliated: Yes


Field evidence from north-south transects tests three tectonic models for Tethys in Western Turkey for when a Late Palaeozoic ocean was closing and an Early Mesozoic ocean opening. In Model 1, a Palaeozoic ocean subducted southwards, rifting continental fragments from Gondwana and opening a Triassic Neo-Tethys to the south. Closure and collision occurred by latest Triassic time. In Model 2, a wide Palaeozoic Tethys subducted northwards with an active Eurasian margin and a passive Gondwana margin. The northern Gondwana margin rifted in the Triassic; fragments either remained nearby (Taurides) or drifted northwards (e.g. Karakaya) attached to a north-subducting plate. New oceanic crust replaced Palaeo-Tethys with Neotethys and back-arc marginal basins opened along the south Eurasian margin (e.g. Kure). In Model 3, a Palaeozoic ocean also subducted northwards opening wide marginal basins. A wide Southern Neotethys opened along the Gondwana margin. Rifted Eurasian (Anatolides) and Gondwana (Taurides) fragments collided in mid-Tethys by latest Triassic time. Field evidence from the Pontides supports north-dipping subduction models (Model 2 or 3 above). Key features are a south-vergent, HP-LT accretionary prism, magmatic are and back-are basin system bordering the Eurasian margin. Also, evidence from the Tauride Mountains favours Model 2 over Model 3. Critically, the Anatolides and Taurides appear to have a common history and were unlikely to have been located on opposite sides of Tethys, as in Model 3.