Geodynamics of Anatolia: Lithosphere Thermal Structure and Thickness

Abstract

We present the first thermal model for the lithosphere in Turkey, which shows a highly heterogeneous pattern associated with mosaics of the Tethyan and modern subduction systems. We calculate a regionally average crustal density of 2.90 g/cm3 consistent with the presence of large volumes of mafic material. The Moho temperature with a regionally average value of 650–850 °C shows strong short‐wavelength variations. Lithosphere thinning to 50–75 km in most of western Anatolia may have developed in response to the Hellenic slab rollback, while the Neoproterozoic block in the Menderes Massif preserves a 150 km deep lithosphere root. In central Anatolia, the lithosphere thickness decreases southward from 100–150 to 50–60 km along a linear belt of young basaltic volcanism, followed by a belt of a 150 km thick lithosphere. We interpret this characteristic pattern by a SE dipping paleoslab beneath the western Taurides, which may cause the Cyprus subduction melting zone to deviate toward NW and NE. The Eastern Pontides‐Lesser Caucasus have 150–200 km thick lithosphere roots caused by collisional tectonics. The East Anatolian Plateau is underlain by a 80–140 km thick lithosphere, which suggests the presence of significant continental fragments; the patchy pattern of its thermal heterogeneity may be explained by teared and fragmented Tethyan slabs. A poor correlation between the lithosphere thermal structure, heat flux, the Neogene volcanic regions, and mantle seismic velocities implies that seismic anomalies are essentially controlled by heterogeneous mantle hydration by subduction systems of different ages and cannot be explained by temperature variations alone.

Geodynamics, seismicity, and seismic hazards of the Caucasus

“…4b) beneath the central and eastern parts of the Greater Caucasus and the Lesser Caucasus. There is a reasonably satisfactory agreement between the thermal model of Alexidze et al (1993) and those developed for the western Black Sea, northern Turkey, and Crimea (Tesauro et al, 2009(Tesauro et al, , 2010 and for the southern Black Sea and Lesser Caucasus (Artemieva and Shulgin, 2019). Also, the thermal model is in general agreement (i) with the local Pwave tomography model (Zabelina et al, 2016), showing negative seismic velocity anomalies at the depth of 30 km in the same parts of the Greater and Lesser Caucasus, which is likely to be associated with higher temperature at the depths, and (ii) with known past volcanic activities ( Fig.…”

Morphological and multivariate statistical analysis of quaternary monogenetic vents in the Central Anatolian Volcanic Province (Turkey): Implications for the volcano-tectonic evolution

“…The hot upper mantle with very slow shear velocities ( 4.2 km/s; Delph et al, 2017) beneath the CAVP has been well-documented (e.g., Biryol et al, 2011;Abgarmi et al, 2017;Reid et al, 2017;Artemieva and Shulgin, 2019). The low-velocity anomalies tentatively illustrated in Fig.…”

The Influence of the North Anatolian Fault and a Fragmenting Slab Architecture on Upper Mantle Seismic Anisotropy in the Eastern Mediterranean

“…Additionally, patches of faster wavespeeds and deeper melt equilibration depths beneath parts of the Kırşehir block suggest a relatively thicker lithosphere (Fichtner et al., 2013; Reid et al., 2019). More variable lithospheric thickness, including some areas 150 km thick, has been suggested from heat flow modeling and isostatic considerations (Artemieva & Shulgin, 2019), yet evidence for the proposed thick lithospheric roots is mostly lacking in regional tomographic models (e.g., Biryol et al., 2011; Fichtner et al., 2013; Kounoudis et al., 2020; Portner et al., 2018).…”