Shallow crust structure of the Büyük Menderes graben through an analysis of gravity data

Murat SARI,F. Figen ALTINOĞLU,Ali AYDIN

doi:10.3906/yer-1712-6

Abstract

The Büyük Menderes is one of the most important geostructural features of highly seismically active western Anatolia, Turkey. This article aims to analyze the geological features and the shallow crust structure of the Büyük Menderes graben. To achieve this, six different edge detection filters and a 3D inversion method were applied to the Bouguer gravity data to detect new lineaments and shallow crust topographies. A renewed fault map of the Büyük Menderes graben is the significant contribution of the present study. New lineaments were detected in the western, southeastern, and northern parts of the region, where intense seismicity was observed. The basement, the upper-lower crust undulation, and their relations were analyzed in detail. The maximum sediment thickness was defined as 4.1 km. The subsurface depths are increasing in N-S and W-E directions. The new determined lineaments may be a topic of future research to warrant attention.

Highlights

Western Anatolia is a tectonically complex, seismically active, lithospheric extension and thinning region
By using the Bouguer gravity anomaly data, the linear features and the 3D subsurface undulation of the Büyük Menderes graben and surroundings were carefully studied in the present work
The gravity anomaly values of western Anatolia get higher from the east to the west (Sarı and Şalk 2002)

Summary

Introduction

Western Anatolia is a tectonically complex, seismically active, lithospheric extension and thinning region. The mainly E-W trending Büyük Menderes and Gediz grabens are the most specific structures of the region. The active tectonics in western Anatolia are controlled by the synergic movement of the Eurasian, African, and Arabian plates (Figure 1). The Gediz and Büyük Menderes grabens are characterized by Miocene detachment faulting and core-complex formation, and high angle normal faulting controlled the Plio-Quaternary graben floor fillings with 140 km in length and 2.5–14 km in width, localized to the north and the south by the Menderes Massif metamorphic complex (Yilmaz et al, 2000; Sözbilir, 2001; Bozkurt and Sözbilir, 2004, 2006; Çiftçi and Bozkurt, 2009)

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