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

Authors :
Robertson, Alastair H.F.
Ustaomer, Timur
Pickett, Elizabeth A.
Collins, Alan S.
Andrew, Theo
Dixon, John E.
Source :
Journal of the Geological Society. May, 2004, Vol. 161 Issue 3, p501, 11 p.
Publication Year :
2004

Abstract

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 rifled 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 arc and back-arc 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. Keywords: Western Turkey, Tethys, Triassic, subduction.

Subjects

Subjects :
Geology -- Research
Earth sciences

Details

Language :
English
ISSN :
00167649
Volume :
161
Issue :
3
Database :
Gale General OneFile
Journal :
Journal of the Geological Society
Publication Type :
Academic Journal
Accession number :
edsgcl.117260109