Tectonic evolution of Early Paleozoic island-arc systems and continental crust formation in the Caledonides of Kazakhstan and the North Tien Shan

Research reveals the complex tectonic evolution of Early Paleozoic island-arc systems and continental crust formation in the Caledonides of Kazakhstan, particularly within the UNESCO World Heritage Site Saryarka. The study identifies two distinct volcanic belts—Saryarka and Shyngyz-North Tien Shan—each with unique geological structures and isotopic compositions. The Saryarka belt exhibits a complex fold-nappe structure formed during the middle Arenigian to middle Llanvirnian periods, while the Shyngyz-North Tien Shan belt shows a simpler fold structure, composed of Middle-Late Ordovician volcanic and plutonic associations. These findings highlight the heterogeneous nature of the continental crust in different segments of the Kazakh Caledonides, with upper crustal units dominated by island-arc complexes and lower crustal units by mafic rocks. The study employs structural and isotopic analyses to trace the tectonic history and crustal composition, offering insights into the geological processes shaping this region.

Degtyarev, K. E. (2011). Tectonic evolution of Early Paleozoic island-arc systems and continental crust formation in the Caledonides of Kazakhstan and the North Tien Shan. Geotectonics, 45(1), 23–50. https://doi.org/10.1134/s0016852111010031