Pervasively Thin Anatolian Lithosphere With Elevated Upper Mantle Temperatures in the East: Insights From Bayesian Thermo‐Compositional Inversion

Abstract

Uplift and widespread Late Miocene‐present magmatism in Anatolia are commonly attributed to lithospheric thinning, possibly facilitated by the arrival of hot mantle plume material. There are various lines of evidence for thin present‐day lithosphere, but the spatial extent and degree of lithospheric thinning and the underlying mantle temperatures remain debated. Here we apply a Bayesian thermo‐compositional approach that jointly inverts surface‐wave dispersion, elevation and surface heat flow for temperatures of the lithosphere and underlying mantle to 360 km depth. Our results reveal that thermal lithospheric thickness across the study region is generally thin, 40–85 km, with thicker lithosphere (>70 km) beneath the Central Pontides and northernmost Arabia and exceptionally thin (40–55 km) lithosphere beneath the Eastern Pontides and the region between the Central and Eastern Anatolian Plateaus. Furthermore, we find a pronounced west‐to‐east increase in mantle potential temperature of ∼140C across 35E. The sharp mantle temperature gradient implies that any inflow of hot plume material is largely confined to the east and therefore is unlikely to be a primary driver of Anatolia's westward motion. The pervasively thin but variable lithospheric thickness indicates widespread, yet heterogeneous lithospheric removal, with the influx of hot mantle material potentially enhancing thinning beneath eastern Anatolia.