ABIC-based surficial density model of Türkiye and tectonic implications

This study presents a surficial density model of Türkiye derived from the Akaike Bayesian Information Criterion (ABIC) inversion of terrestrial gravity data. By regularizing the gravity field through spatial smoothness constraints, the ABIC method yields optimal Bouguer reduction densities that reflect lateral variations in tectonic architecture, lithological heterogeneity, and upper crustal structure. Over 52,000 georeferenced observations reveal surficial densities ranging from 2.20 to 4.00 g/cm³, with a statistically robust mean of 2.669 ± 0.002 g/cm³ (95% confidence interval), suitable for precision gravity reduction and geodynamic applications. The derived density field delineates key tectonic domains across the Anatolian lithosphere, including extensional provinces, compressional belts, basement massifs, and suture zones. Broad density gradients correlate with active fault systems and inherited terrane boundaries, while anomalous density zones highlight regions of magmatic emplacement, crustal thinning, or sedimentary infill. Integration with global lithological data reveals strong density-lithology agreement in carbonate, volcanic, and crystalline terrains, whereas discrepancies in evaporitic and unconsolidated sedimentary units underscore the effects of subsurface mixing and inversion smoothing. These results demonstrate the capacity of ABIC-derived surficial density models to resolve shallow crustal heterogeneity and inform tectonic segmentation, lithospheric rheology, and geothermal prospectivity across seismically active continental domains.