Metamorphic imprint of ridge subduction on the Neo-Tethyan ophiolites from the Saka Unit (Central Pontides, northern Turkey)

Date

2020-09-01

Author

Frassi, Chiara
Rebay, Gisella
Marroni, Michele
Sayıt, Kaan
Göncüoğlu, Mehmet Cemal
Ellero, Alessandro
Ottria, Giuseppe
Pandolfi, Luca

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

266
views

0
downloads

The Intra-Pontide suture zone is the northernmost ophiolite suture zone exposed in the Anatolian peninsula. It consists of several variably deformed and metamorphosed tectonic units derived from the Neo-Tethyan IntraPontide oceanic (IPO) basin, and its continental margins that are currently represented by the Istanbul Zonguldak and the Sakarya terranes. Recent data suggests that the IPO was a wide supra-subduction oceanic basin whose closure began in the uppermost Early Jurassic by a north dipping intra-oceanic subduction that divided the IPO into two different oceanic areas, namely IPO1 and IPO2. The Saka Unit is a small tectonic unit exposed in the eastern portion of the Intra-Pontide suture zone in the Central Pontides, which is interpreted as a tectonic melange produced during the intra-oceanic subduction that led to the closure of IPO1. The unit was affected by polyphase deformation and epidote-amphibolite facies metamorphism peak conditions experienced during the uppermost Middle Jurassic. Metamorphic studies and thermodynamic investigations constrain the peak pressure conditions to T approximate to 650-700 degrees C and P approximate to 0.9-1.3 GPa. These conditions reveal a 'hot' and anomalous geothermal gradient (15-22 degrees C/km) with respect to those of the other ophiolite-bearing units of the IntraPontide suture zone involved in the subduction. This anomalous gradient was herein attributed to the thermal pulse produced by the subduction of the IPO1 mid-oceanic ridge. The final re-equilibration occurred under greenschist facies conditions during the Early Cretaceous exhumation, when the oceanic lithosphere of the IPO was completely consumed and the continental collision between the Istanbul-Zonguldak and Sakarya terranes occurred.

Subject Keywords

Intra-oceanic ridge subduction, Pseudosections, Metamorphic evolution, Intra-Pontide Suture zone, Central Pontides, Turkey

URI

https://hdl.handle.net/11511/30306

Journal

JOURNAL OF ASIAN EARTH SCIENCES

DOI

https://doi.org/10.1016/j.jseaes.2020.104468

Collections

Graduate School of Natural and Applied Sciences, Article

Suggestions

OpenMETU
Core

Tectono-stratigraphy of the Cankiri Basin: Late Cretaceous to early Miocene evolution of the Neotethyan Suture Zone in Turkey Kaymakcı, Nuretdin; White, Stanley H.; van Dijk, Paul M. (2009-01-01) The Cankiri Basin straddles the Izmir-Ankara-Erzincan Suture Zone which demarcates the former position of the northern branch of the Neotethys. It includes more than 3 km of pre-Middle Miocene in-fill related to late Cretaceous to pre-Middle Miocene evolution of the region. The basin has developed on the upper Cretaceous subduction complex and arc related basins of the Neotethys Ocean. The basin fill includes an upper Cretaceous forearc sequence overlain by Paleocene with a local unconformity. The upper Cre...
Burial and exhumation history of the Daday Unit (Central Pontides, Turkey): implications for the closure of the Intra-Pontide oceanic basin Frassi, Chiara; Marroni, Michele; Pandolfi, Luca; Göncüoğlu, Mehmet Cemal; Ellero, Alessandro; Ottria, Giuseppe; Sayıt, Kaan; Mcdonald, Christopher S.; Balestrieri, Maria Laura; Malasoma, Alessandro (2018-02-01) In northern Turkey, the Intra-Pontide suture zone represents one of the first-order tectonic structures located between the Istanbul-Zonguldak and the Sakarya continental terranes. It consists of an E-W-trending assemblage of deformed and variably metamorphosed tectonic units, including sedimentary rocks and ophiolites derived from a Neo-Tethyan oceanic basin, known as the Intra-Pontide oceanic basin. One of these units is represented by the Daday Unit that consists of a block-in-matrix assemblage derived f...
Tectono-stratigraphic and thermal evolution of the haymana basin, Central Anatolia, Turkey Gülyüz, Erhan; Kaymakcı, Nuretdin; Department of Geological Engineering (2015) The Haymana Basin is located on the southernmost tip of the Central Pontides and straddles between the İzmir-Ankara-Erzincan Suture Zone at the north and Intra-Tauride Suture Zone at the south. These suture zones designate the former positions of various branches of the Neotethys Ocean in Turkey, the basins evolved within these zones record the progressive closure of the Neotethys and the collision between Taurides, Kırşehir Block and Pontides during late Cretaceous to Eocene time interval. The Haymana Basi...
TECTONIC CONTROL ON THE DEVELOPMENT OF THE NEOGENE QUATERNARY CENTRAL ANATOLIAN VOLCANIC PROVINCE, TURKEY TOPRAK, V; Göncüoğlu, Mehmet Cemal (1993-12-01) The Neogene-Quaternary Central Anatolian Volcanic Province (CAVP) is elongated in a north-east south-west direction within pre-Oligocene basement in central Turkey. This study investigates the field evidence relating to the development of the CAVP.
GEOCHEMICAL CHARACTERISTICS OF GRANITOIDS ALONG THE WESTERN MARGIN OF THE CENTRAL ANATOLIAN CRYSTALLINE COMPLEX AND THEIR TECTONIC IMPLICATIONS AKIMAN, O; ERLER, A; GONCUOGLU, MC; Güleç, Nilgün Türkan; GEVEN, A; TURELI, TK; KADIOGLU, YK (1993-12-01) The closely related assemblage of igneous and metamorphic rocks that lie within a triangular area approximately bounded by the Tuzgolu Fault, the Ecemis Fault and the Izmir-Ankara-Erzincan Suture and between the lines connecting Ankara, Sivas and Nigde is called the Central Anatolian Crystalline Complex (CACC). The granitoids cropping out within the CACC can be divided areally into three groups: (1) a large number of individual small plutons which form an arcuate set and curve from NE-SW to NW-SE and extend...

Citation Formats

C. Frassi et al., “Metamorphic imprint of ridge subduction on the Neo-Tethyan ophiolites from the Saka Unit (Central Pontides, northern Turkey),” JOURNAL OF ASIAN EARTH SCIENCES, pp. 0–0, 2020, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30306.