Forearc high uplift by lower crustal flow during growth of the Cyprus-Anatolian margin

Abstract

We present a model for the dynamic formation of the forearc high of southern Anatolia where sedimentation in the forearc basin leads to thermally-activated deformation in the lower crust. Our thermo-mechanical models demonstrate that forearc sedimentation increases the temperature of the underlying crust by “blanketing” the heat flux and increasing Moho depth. Deformation switches from frictional to viscous with a higher strain rate led by increased temperature. Viscous deformation changes large-wavelength subsidence into coeval, short-wavelength uplift and subsidence. Models show that forearc highs are intrinsic to accretionary wedges and can grow dynamically and non-linearly at rates dependent on sediment accretion, sedimentation and temperature. The mechanism explains the uplift of the southern margin of the Central Anatolian Plateau and the Neogene vertical motions and upper-plate strain in the Anatolian margin along Central Cyprus. This system is analogous to forearc highs in other mature accretionary margins, like Cascadia, Lesser Antilles or Makran.