Paleozoic Xenoliths in Eocene Plutons: The Evidence for the Destruction of Pre-Jurassic Crystalline Basement Beneath Adjara–trialeti Belt, Lesser Caucasus

Validating far-field deformation styles from the Adjara-Trialeti fold-and-thrust belt to the Greater Caucasus (Georgia) through multi-proxy thermal maturity datasets

“…The Adjara-Trialeti FTB is an orogen bordered mainly by north-vergent frontal reverse faults (Alania et al, 2018;Banks et al, 1997;Gusmeo et al, 2021;Nemčok et al, 2013) and resulting from the structural inversion of a former back-arc rift basin developed on the upper (Eurasian) plate of the northern Neotethys subduction zone (Adamia et al, 1981(Adamia et al, , 2011bBanks et al, 1997;Barrier et al, 2018;Lordkipanidze et al, 1989). The main phase of rifting occurred in the Middle Eocene, characterized by the deposition of a thick volcanic and volcaniclastic succession, accompanied by shallow mafic-to-intermediate intrusions (Adamia et al, 2011b;Banks et al, 1997;Okrostsvaridze et al, 2018;Yılmaz et al, 2000Yılmaz et al, , 2014. The post-rift phase lasted from the Late Eocene/Oligocene to the Early Miocene and was followed by structural inversion since late Middle Miocene times (Gusmeo et al, 2021).…”

“…The Greater Caucasus Basin was characterized by a thin and intruded continental crust in its axial zone, and by a sedimentary succession at least 7-9 km thick (Adamia et al, 2011a(Adamia et al, , 2011bSaintot et al, 2006). The Adjara-Trialeti Basin was underlain by a thicker and less intruded continental crust and filled by a thinner sedimentary succession (with thickness variable along-strike) (Adamia et al, 2011b(Adamia et al, , 2017Gamkrelidze et al, 2019;Nemčok et al, 2013;Okrostsvaridze et al, 2018;Yılmaz et al, 2000Yılmaz et al, , 2014. Between the two basins, a structural high was located, characterized by a very thin sedimentary succession overlying the basement: this J o u r n a l P r e -p r o o f structural high will later crop out as the Dzirula Massif, and more to the east it will represent the basement upon which the Kura Basin and the Kakheti ridge will develop.…”