Mapping crustal structure and deformation using gravity data in the Bursa Basin and surroundings, Türkiye

Authors: BÜLENT ORUÇ, EMİR BALKAN

Abstract: The structure and deformation of the Bursa Basin and surroundings was carried out through the interpretation of Bouguer gravity and isostatic residual gravity anomalies. The spectral analysis was carried out on Bouguer anomalies to obtain the average depths of the crustal structure under the Bursa Basin and surroundings. Parker-Oldenburg algorithm was used to estimate the depths of the interface between upper and lower crust with respect to an average depth and density contrast. We used Mallick-Sharma algorithm to separate the regional gravity anomalies from Bouguer anomalies to estimate the isostatic residual gravity anomalies. Euler deconvolution and two-dimensional density contrast distribution obtained from the isostatic residual gravity anomalies are investigated to highlight the structure of the shallower part of upper crustal domain. We focus on a detailed basin evolution combined with stress field originated from geoid undulation while updating the new neotectonic framework. We also demonstrate kelimeyi significant correlations between the earthquake distribution and stress field variations. The results suggest that the geometry and deformation of upper crust is associated with shallower and deeper multiple fault segments in a strike-slip mechanism with composite pull-apart system.

Keywords: Gravity anomalies, Euler deconvolution, inverse modeling, stress field, tectonic implications

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