Evaluation of the Plio-Quaternary tectonic stress regime from fault kinematic analysis in the lake Van Basin (Eastern Anatolia)

• Published in: Journal of structural geology 2020-11, Vol.140, p.104157, Article 104157
• Main Authors: Selçuk, Azad Sağlam, Erturaç, Mehmet Korhan, Sunal, Gürsel, Çakır, Ziyadin
• Format: Article
• Language: English
• Subjects: East Anatolia; Kinematic analysis; Lake Van basin; Stress regime, Pleistocene lake terraces; Transpression
• ISSN: 0191-8141; 1873-1201
• DOI: 10.1016/j.jsg.2020.104157

We focus on the Neogene–Quaternary tectonic evolution of the Lake Van Basin located within the Turkish-Iranian Plateau. To better understand the complex tectonic history of the region and determine the paleostress patterns, we investigate and report on the geometric, structural, and kinematic characteristics of the Basin based on field observations of fault-slip orientations which are classified according to radiometric ages of the basin stratigraphy. The analysis of large-scale structures and fault kinematics indicate that three different deformation phases prevailed in the Lake Van Basin during the Neogene-Quaternary periods. Phase 1 is characterized by NW-SE extension and NE-SW contraction that gave rise to the development of strike-slip faults with thrust or normal components during the late Miocene, deforming the fluvial sediments which expose at east/northeast of the Basin. Phase 2 is characterized in fluvial and lake deposits of the Middle Pleistocene, deformed by dominant contraction stress regime effective along NW-SE direction. The late Pleistocene tectonic regime (Phase 3) consists of transpressional deformation that develops under NNW-SSE compression and ENE-WSW extension. According to our analysis, the present-day deformation pattern of the Lake Van Basin is dominated by compression at east, while at the northern part is transtensional. •Active faults of the Lake Van Basin is detailed with kinematic analysis from fault slip data.•Three different deformation phases is identified from the late Miocene through the late Pleistocene.•Compressional and transtensional tectonic regime alternated to dominate evolution of the Lake Van Basin.•U/Th dating of the Pleistocene terraces revealed the oldest (384 ka; +60 m) and highest (~ 213 ka; +130 m) levels of the Lake Van.