The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance

I. Onur Tunc

The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance

Abstract

The pre-Liassic basement rocks of the Biga Peninsula, located in the westernmost part of the Sakarya Zone, consist of metamorphic units thought to represent different continental basements to the north and south, with a suture (ophiolitic/mélange) zone in between. The Çetmi mélange, considered to be located between the Sakarya Zone in the south and the Ezine Zone in the north, is interpreted as a subduction accretionary mélange belonging to the Intra-Pontid Ocean. Consequently, it has been assumed that a suture passes through this part of the peninsula. The units to the east and west of the Kazdağ Massif and those west of Karabiga differ from each other in terms of Mesozoic cover units. While the metamorphic basement rocks in the southeastern part of the Kazdağ high are covered by a platform carbonate sequence, a clastic, high-energy environment represented by the Çetmi group developed in the west-northwest of the Kazdağ high during the same period. The Çetmi group is the first and only unit in the region that has not undergone metamorphism and is directly related to both different basement rocks and the overlying sedimentary sequences. The Çetmi group overlies the high-grade metamorphic rocks of the Kazdağ Massif and the low-grade metamorphic rocks of the Örenli metamorphics tectonically in the west of the Kazdağ Massif, while it unconformably overlies low-grade metamorphic rocks of Ediacaran-Late Paleozoic age in the west of Karabiga. Accordingly, the Çetmi group consists of a sedimentary-volcanic-volcanoclastic matrix and blocks within this matrix. This unit shows similarities with Mesozoic units distinguished further east in the Western Pontides.

Keywords

Thanks

Prof. Dr. Erdinç YİĞİTBAŞ is thanked for his constructive and valuable comments and suggestions. I would also like to thank the Reviewers for their contributions to the improvement of the manuscript.

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Details

Primary Language

English

Subjects

Geological Sciences and Engineering (Other)

Journal Section

Research Article

Authors

I. Onur Tunc ^*
0000-0002-4273-9175
Türkiye

Publication Date

April 30, 2026

Submission Date

January 5, 2026

Acceptance Date

March 10, 2026

Published in Issue

Year 2026 Volume: 13 Number: 1

IZ

https://izlik.org/JA26WM34YR

Cite

RIS / Bibtex

APA

Tunc, I. O. (2026). The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance. International Journal of Environment and Geoinformatics, 13(1), 31-40. https://izlik.org/JA26WM34YR

AMA

1.Tunc IO. The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance. IJEGEO. 2026;13(1):31-40. https://izlik.org/JA26WM34YR

Chicago

Tunc, I. Onur. 2026. “The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance”. International Journal of Environment and Geoinformatics 13 (1): 31-40. https://izlik.org/JA26WM34YR.

EndNote

Tunc IO (April 1, 2026) The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance. International Journal of Environment and Geoinformatics 13 1 31–40.

IEEE

[1]I. O. Tunc, “The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance”, IJEGEO, vol. 13, no. 1, pp. 31–40, Apr. 2026, [Online]. Available: https://izlik.org/JA26WM34YR

ISNAD

Tunc, I. Onur. “The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance”. International Journal of Environment and Geoinformatics 13/1 (April 1, 2026): 31-40. https://izlik.org/JA26WM34YR.

JAMA

1.Tunc IO. The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance. IJEGEO. 2026;13:31–40.

MLA

Tunc, I. Onur. “The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance”. International Journal of Environment and Geoinformatics, vol. 13, no. 1, Apr. 2026, pp. 31-40, https://izlik.org/JA26WM34YR.

Vancouver

1.I. Onur Tunc. The Çetmi Group in the Biga Peninsula (NW Anatolia-Türkiye): Reassessment of Its Nature and Tectonostratigraphic Significance. IJEGEO [Internet]. 2026 Apr. 1;13(1):31-40. Available from: https://izlik.org/JA26WM34YR