Research Article

The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean

Volume: 69 Number: 1 January 30, 2026
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The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean

Abstract

The Anatolian Diagonal is a prominent left-lateral shear zone that plays a key role in the neotectonic framework of Türkiye, spanning 170 km between the Central Anatolian and East Anatolian fault zones and extending approximately 850 km from Erzincan to the Cyprus Arc. Its southwestern onshore termination is represented by the Ecemiş-Deliler Fault, while its offshore continuation, the Biruni Fault, trends toward the Cyprus Arc. This study aims to characterise the southwestern end of the Ecemiş-Deliler Fault through geomorphic markers, and to identify the Biruni Fault using key offshore seismic reflection profiles and geological cross-sections provided by Turkish Petroleum. Focal mechanism solutions for offshore seismic events are also examined to assess fault kinematics. Based on onshore observations, a left-lateral offset of 18 km along the Göksu River indicates a long-term slip rate of approximately 2.25 mm/year at the southwestern end of the Ecemiş-Deliler Fault. Offshore, detailed definition and mapping of the Biruni Fault revealed that it comprises a zone of closely spaced, parallel strike-slip segments in its northeastern sector, transitioning into a single linear fault trace that extends south westward toward the Aegean Arc. Despite its clear morphological expression, the southwest end of Ecemiş-Deliler fault and the Biruni Fault of the Anatolian Diagonal have low seismic activity, likely because most regional deformation is accommodated further west along the Antalya-Kekova Fault Zone and the Ptolemy–Pliny–Strabo Fault Zone. The restraining stepovers of the Antalya Thrust and Fethiye Thrust between these structures provide new insight into a slip partitioning in the eastern Mediterranean.

Keywords

References

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Details

Primary Language

English

Subjects

Structural Geology and Tectonics

Journal Section

Research Article

Early Pub Date

December 16, 2025

Publication Date

January 30, 2026

Submission Date

August 17, 2025

Acceptance Date

September 23, 2025

Published in Issue

Year 2026 Volume: 69 Number: 1

APA
Şahbaz, N., Tunçel, E., Kaypak, B., & Seyitoğlu, G. (2026). The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean. Türkiye Jeoloji Bülteni, 69(1), 45-72. https://doi.org/10.25288/tjb.1764368
AMA
1.Şahbaz N, Tunçel E, Kaypak B, Seyitoğlu G. The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean. Geol. Bull. Turkey. 2026;69(1):45-72. doi:10.25288/tjb.1764368
Chicago
Şahbaz, Nuray, Esra Tunçel, Bülent Kaypak, and Gürol Seyitoğlu. 2026. “The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean”. Türkiye Jeoloji Bülteni 69 (1): 45-72. https://doi.org/10.25288/tjb.1764368.
EndNote
Şahbaz N, Tunçel E, Kaypak B, Seyitoğlu G (January 1, 2026) The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean. Türkiye Jeoloji Bülteni 69 1 45–72.
IEEE
[1]N. Şahbaz, E. Tunçel, B. Kaypak, and G. Seyitoğlu, “The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean”, Geol. Bull. Turkey, vol. 69, no. 1, pp. 45–72, Jan. 2026, doi: 10.25288/tjb.1764368.
ISNAD
Şahbaz, Nuray - Tunçel, Esra - Kaypak, Bülent - Seyitoğlu, Gürol. “The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean”. Türkiye Jeoloji Bülteni 69/1 (January 1, 2026): 45-72. https://doi.org/10.25288/tjb.1764368.
JAMA
1.Şahbaz N, Tunçel E, Kaypak B, Seyitoğlu G. The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean. Geol. Bull. Turkey. 2026;69:45–72.
MLA
Şahbaz, Nuray, et al. “The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean”. Türkiye Jeoloji Bülteni, vol. 69, no. 1, Jan. 2026, pp. 45-72, doi:10.25288/tjb.1764368.
Vancouver
1.Nuray Şahbaz, Esra Tunçel, Bülent Kaypak, Gürol Seyitoğlu. The Biruni Fault of the Anatolian Diagonal: Morphological, Seismological and Seismic Reflection Data and Implications for the Neotectonic Framework of the Eastern Mediterranean. Geol. Bull. Turkey. 2026 Jan. 1;69(1):45-72. doi:10.25288/tjb.1764368

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