Miocene core complex development and coeval supradetachment basin evolution of Paros, Greece

Abstract

This study evaluates the tectonosedimentary evolution of Paros, Greece using apatite and zircon (U-Th)/He dating to assess the currently accepted kinematic history and resolve controversy about the formation of and sources to the Paros supradetachment basin. Overdispersed and improbable results in the footwall suite of zircons are examined using laser ablation depth-profiling to address the inherent assumption of homogeneous parent nuclide distribution in the zircon (U-Th)/He technique. Results from footwall zircon (U-Th)/He analyses indicate rapid cooling in excess of 100 degrees C/km from 11 - 7 Ma, which confirms rapid core complex exhumation along the Naxos-Paros low-angle extensional detachment. The suite of detrital zircons preserves the multi-stage Mesozoic-Cenozoic tectonometamorphic history of the central Aegean Sea and was deposited synchronously with progressive core complex development. Laser ablation data suggest that parent nuclide zonation in zircon poses a significant challenge to the reliability of (U-Th)/He dating which can be corrected by forward modeling unique alpha-ejection corrections.