Late Miocene–early Pliocene tectonic to erosional exhumation in the northwest of the Arabia–Eurasia collision zone

Abstract

AbstractThe exhumation of actively deforming orogenic systems is commonly due to the incision of river systems in response to tectonically driven surface uplift. However, a regional base level and/or climatic variations can also cause erosional exhumation. The temporal and spatial distinction of the dominant mechanism during the topographic evolution of orogens is challenging. Using detailed morphological analyses and thermal modelling of an intrusive body through triple dating (zircon U–Pb, ZHe, and AHe), combined with the previously published structural, detrital, and bedrock low‐temperature thermochronometry (apatite fission track and apatite helium) analysis, the transition from early Oligocene (~27 Ma) and middle Miocene (~12 Ma) tectonic exhumation to late Miocene–early Pliocene (~7–5 Ma) river incision and erosional exhumation in the Talesh Mountains in the NW of the Arabia–Eurasia collision zone was documented. The late Miocene‐early Pliocene incision and the contemporaneous rapid exhumation documented in the Talesh Mountains are related to the base‐level fall of the Caspian Sea due to its isolation from the Paratethys domain. The effect of this base‐level fall then migrated to the margin of the Iranian Plateau and captured the overspilled basins (~4 Ma).