Structural analysis and identification of ore-controlling structures in the Kaeryongkule lead-zinc ore field, Xinjiang Uygur Autonomous Region

The Kaeryongkule lead-zinc ore field is located in the Tianshan giant lead-zinc mineralization belt, and its structural characteristics and ore-controlling structures are still lack systematic analysis. Based on large-scale geological mapping of the ore field, structural analysis and paleostress inversions were conducted and the ore-controlling structures were identified for the Kaeryongkule lead-zinc ore field. An angular unconformity and two stages of top-to-the-south thrust-nappe structures were identified. The Early Permian angular unconformity occurs between the Lower Permian Balikelike Formation and the underlying high-angle cleavaged rocks. The early thrust-nappe structure occurred during the Early Permian and caused the Middle Devonian Tuogemaiti Formation limestone to thrust over the Lower Permian Balikelike Formation. While the thrust-nappe structures occurred during the Early Miocene and resulted in the Middle Devonian Tuogemaiti Formation limestone to thrust over the Lower Cretaceous Kezilesu Group. Paleostress inversion of fault-slip data from the Kaeryongkule lead-zinc ore field revealed four stages of tectonic regimes: 1) NW-SE contractional regime; 2) strike-slip regime (NW-SE contraction and NE-SW extension); 3) NW-SE extensional regime; 4) contractional regime. The first to third tectonic regimes occurred during the Early Permian, resulting from syn-orogenic shortening, tectonic transition, and post-orogenic extension during the Late Paleozoic orogeny of the Tianshan orogenic belt. While the fourth tectonic regime occurred during the Early Miocene, triggered by the far-field effect of the Cenozoic India-Asia collision. Ore-controlling structures in the Kaeryongkule lead-zinc ore field include low-angle thrust faults and the angular unconformity, as well as high-angle strike-slip faults and normal faults.