A Model of the Crust and Upper Mantle Structures in Central Anatolia, Turkey, Constrained by Gravity and Seismic Data

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University of Alabama Libraries

The complex tectonic setting of the easternmost Mediterranean Sea and central Anatolia remains largely unresolved. Previous studies, mostly based on seismic investigations, presented results that conflicted with each other. The purpose of this study is to use gravity modeling to distinguish which aspects of previously published work is consistent with Earth’s gravity signal. For this purpose, I constructed gravity model profiles between longitudes 30°E and 38°E, each ranging from latitude 32°N to latitude 40°N. In these models, I incorporated structural boundaries published in previous work and compared to the satellite based EIGEN-6C4 gravity data product, what the gravity signal of the structures would be. Based on my gravity models, I identified that the crustal thickness is increasing in northern as well as in eastern direction. My gravity models show that the Cyprus slab subducts with an angle of 29 and 31 degrees along longitudes 31°E and 32°E, respectively. Even though the Cyprus slab is present between longitudes 33°E and 34°E, it has most likely experienced slab breakoff which might cause lithospheric removal farther to the north in central Anatolia. The last three profiles longitude 35°E, 36°E and 37°E do not have the Cyprus slab.The central Anatolian lithosphere is thinner than both the African and Arabian lithosphere. The average lithospheric thickness is 75-81 km in central Anatolia and approximately 97 and 105 km in the African and Arabian plates, respectively. When the densities were compared to the African and Arabian plates, I observed relatively low-density crust and uppermost mantle in central Anatolia. The thin lithosphere and low-density material may indicate thermal alteration associated with delamination, slab breakoff and/or drip tectonics in central Anatolia.

Electronic Thesis or Dissertation
central Anatolia, Cyprus slab, eigen 6c4, forward modeling, gravity, seismic