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The 2023 Mw7.7 Pazarcik earthquake caused a reversal in vertical motion along the SW branch of the East Anatolian fault.

Authors :
Gong, Zheng
Li, Haibing
Zhang, Huiping
Kuterdem, Kerem
Wang, Shiguang
Si, Jialiang
Zheng, Yong
Liang, Peng
Li, Chenglong
Li, Chuanyou
Ren, Zhikun
Yu, Jingxing
Zhou, Xiaocheng
Xu, Yueren
Ma, Zhifa
Li, Junjie
Tang, Fangtou
Source :
Journal of Structural Geology. Jul2024, Vol. 184, pN.PAG-N.PAG. 1p.
Publication Year :
2024

Abstract

While the structural deformation at the Arabia-Anatolia-Africa junction is critical for understanding eastern Mediterranean tectonics, it remains debatable (extensional or compressional). Field survey of the 2023 Mw7.7 Pazarcik earthquake surface rupture along the Amanos Range, and microstructure and composition analyses of related fault rock were performed to investigate this issue. The surface rupture shows transtensional branches, with the main and secondary strands displaying sinistral (normal) offsets of 2.0–4.0 (0.4–0.9) and 1.0 (0.2) m. Slip plane of the secondary fault is marked by a ∼20 cm wide extensional fracture dividing fault breccia from gouge. Meanwhile, the gouge (26 % calcite, 38% serpentine and 36% smectite) is also dominated by tension cracks microscopically. In contrast to the widespread extensional deformation, geological evidence imply that this fault had experienced reverse slip in the Quaternary, as shown by thrusting of serpentine onto alluvium and the consistency of R foliations with reverse shear. We interpret it as the SW continuation of the East Anatolia fault (EAF) that was formerly characterized by transpressional deformation, and reactivated transtensionally due to the change of fault strike during this earthquake. In the broader Mediterranean tectonics framework, the Amanos segment might be interpreted as a recently formed component linking the Karasu fault to the EAF. • The coseismic rupture along the Amanos Range is overall transtensional. • The largest branch fault reactivated was previously transpressional. • This transformation happened in the Quaternary. • It highlights the tectonic evolution in the Arabia-Anatolia-Africa junction zone. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
01918141
Volume :
184
Database :
Academic Search Index
Journal :
Journal of Structural Geology
Publication Type :
Academic Journal
Accession number :
177747287
Full Text :
https://doi.org/10.1016/j.jsg.2024.105172