In northern Turkey, the Intra-Pontide suture (IPS) zone divides the Istanbul-Zonguldak and the continental terranes (Göncüoğlu et al. 2000). It consists of an assemblage of several oceanic and continental units characterized by different age, metamorphic imprint and deformation history. In the Central Pontides, the IPS zone is a pre- late Paleocene imbricate stack where an ophiolite unit (Ayli Dağ ophiolite Unit) and an ophiolite-bearing mèlange (Arkot Dağ Mèlange), derived from a NeoTethyan oceanic basin (the Intra-Pontide oceanic basin: Göncüoğlu et al. 2008) are associated with four metamorphic units (i.e. Saka, Emirkoy, Daday and Domuz Dağ Unit) (Frassi et al., 2016). In the Daday Massif, the Daday Unit is an assemblage of tectonic slices having a monogenic composition (micaschists, paragneisses, marbles, actinolite-bearing schists and quarzites) derived from a supra-subduction oceanic crust (Sayit et al., 2016) and related deep-sea sediments of Middle Jurassic age. Structural analyses, P-T estimates and Ar-Ar dating allow to elaborate a P-T-t-d path (Frassi et al., 2017) in which the D1 phase was acquired during the Late Jurassic by tectonic underplating at 35-42 km of depth. The following D2, D3 and D4 phases produced the exhumation up to shallower structural levels. The high geothermal gradient detected during the D2 phase indicates that the Daday Units was exhumed during a continent arc collisional setting. The structure of the IPS zone is unconformably sealed by the upper Paleocene - Eocene deposits and lately reworked by the North Anatolian Fault Zone (D5). Göncüoğlu M.C., Turhan N., Senturk K., Ozcan A. & Uysal S. 2000. A geotraverse across NW Turkey: tectonic units of the Central Sakarya region and their tectonic evolution. In Tectonics and magmatism in Turkey and the surrounding area (eds E. Bozkurt, J. Winchester & J.A. Piper), Geol. Soc. Lond. Special Publ. 173, 139-161. Göncüoğlu M.C., Gürsu S., Tekin U.K. & Koksal S. 2008. New data on the evolution of the Neotethyan oceanic branches in Turkey: Late Jurassic ridge spreading in the Intra-Pontide branch. Ofioliti, 33, 153–164. Frassi C., Göncüoğlu M.C., Marroni M., Pandolfi L., Ruffini L. Ellero A., Ottria G. & Sayit K. 2016. The Intra-Pontide Suture Zone in the Tosya-Kastamonu area, Northern Turkey. J. of Maps, 12, 211-219. Frassi C., Marroni M., Pandolfi L., Göncüoğlu M.C., Ellero A., Ottria G., Sayit K., McDonald C.S., Balestrieri M.L., Malasoma A., Crowley Q.G. 2017. Burial and exhumation history of the Daday Unit (Central Pontides, Turkey): implications for the closure of the Intra-Pontide oceanic basin. Geol. Mag., doi10.1017/S0016756817000176. Sayit K., Marroni M., Göncüoğlu M.C., Pandolfi L., Ellero A., Ottri, G. & Frassi C. 2016. Geological setting and geochemical signatures of the mafic rocks from the Intra-Pontide suture zone: implications for the geodynamic reconstruction of the Mesozoic Neotethys. Intern. J. Earth Sciences, 105, 39–64.
Burial and exhumation history of the Daday Unit (Central Pontides, Turkey)
Frassi C.;Marroni M.;Pandolfi L.;
2017-01-01
Abstract
In northern Turkey, the Intra-Pontide suture (IPS) zone divides the Istanbul-Zonguldak and the continental terranes (Göncüoğlu et al. 2000). It consists of an assemblage of several oceanic and continental units characterized by different age, metamorphic imprint and deformation history. In the Central Pontides, the IPS zone is a pre- late Paleocene imbricate stack where an ophiolite unit (Ayli Dağ ophiolite Unit) and an ophiolite-bearing mèlange (Arkot Dağ Mèlange), derived from a NeoTethyan oceanic basin (the Intra-Pontide oceanic basin: Göncüoğlu et al. 2008) are associated with four metamorphic units (i.e. Saka, Emirkoy, Daday and Domuz Dağ Unit) (Frassi et al., 2016). In the Daday Massif, the Daday Unit is an assemblage of tectonic slices having a monogenic composition (micaschists, paragneisses, marbles, actinolite-bearing schists and quarzites) derived from a supra-subduction oceanic crust (Sayit et al., 2016) and related deep-sea sediments of Middle Jurassic age. Structural analyses, P-T estimates and Ar-Ar dating allow to elaborate a P-T-t-d path (Frassi et al., 2017) in which the D1 phase was acquired during the Late Jurassic by tectonic underplating at 35-42 km of depth. The following D2, D3 and D4 phases produced the exhumation up to shallower structural levels. The high geothermal gradient detected during the D2 phase indicates that the Daday Units was exhumed during a continent arc collisional setting. The structure of the IPS zone is unconformably sealed by the upper Paleocene - Eocene deposits and lately reworked by the North Anatolian Fault Zone (D5). Göncüoğlu M.C., Turhan N., Senturk K., Ozcan A. & Uysal S. 2000. A geotraverse across NW Turkey: tectonic units of the Central Sakarya region and their tectonic evolution. In Tectonics and magmatism in Turkey and the surrounding area (eds E. Bozkurt, J. Winchester & J.A. Piper), Geol. Soc. Lond. Special Publ. 173, 139-161. Göncüoğlu M.C., Gürsu S., Tekin U.K. & Koksal S. 2008. New data on the evolution of the Neotethyan oceanic branches in Turkey: Late Jurassic ridge spreading in the Intra-Pontide branch. Ofioliti, 33, 153–164. Frassi C., Göncüoğlu M.C., Marroni M., Pandolfi L., Ruffini L. Ellero A., Ottria G. & Sayit K. 2016. The Intra-Pontide Suture Zone in the Tosya-Kastamonu area, Northern Turkey. J. of Maps, 12, 211-219. Frassi C., Marroni M., Pandolfi L., Göncüoğlu M.C., Ellero A., Ottria G., Sayit K., McDonald C.S., Balestrieri M.L., Malasoma A., Crowley Q.G. 2017. Burial and exhumation history of the Daday Unit (Central Pontides, Turkey): implications for the closure of the Intra-Pontide oceanic basin. Geol. Mag., doi10.1017/S0016756817000176. Sayit K., Marroni M., Göncüoğlu M.C., Pandolfi L., Ellero A., Ottri, G. & Frassi C. 2016. Geological setting and geochemical signatures of the mafic rocks from the Intra-Pontide suture zone: implications for the geodynamic reconstruction of the Mesozoic Neotethys. Intern. J. Earth Sciences, 105, 39–64.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
