Constraining Age of Deformation Stages in the South-Western Part of Verkhoyansk Fold-and-Thrust Belt by Apatite and Zircon Fission-Track Analysis

Zircon fission track analysis was carried out for Mesoproterozoic to Lower Paleozoic sedimentary rocks of the South-Verkhoyansk sector of the Verkhoyansk fold-and-thrust belt. The age of thrusting stages was constrained in this region. The early stage of deformations dated as 160 Ma, the main stage dated as from 70 to 90 Ma. Thermal history modeling on apatite allowed us to establish the youngest stage of erosion from 20 to 30 Ma, which indirectly indicates the reactivation of tectonic processes in the region at the boundary of Paleogene and Neogene. The degree of heating of the rocks increases in the east direction, and if in the frontal zone the fission tracks were annealed only in apatite, then in the Sette-Daban zone fission tracks were annealed both in apatite and in zircon.