Geology and He-Ar-S-Pb isotope constraints on the genesis of the Sidaogou gold deposit in Liaodong Peninsula, northeastern North China Craton

摘要

The large Sidaogou gold deposit in the Liaodong Peninsula is a typical alteration-type gold system, hosted in Paleoproterozoic metamorphic rocks of Gaixian Formation. Ore paragenesis indicates Sidaogou mineralization occurred in four stages: (1) early ore stage S1 (quartz + albite), (2) main ore stage S2 (quartz + sericite + pyrite + gold), (3) secondary ore stage S3 (quartz + polymetallic sulfide +/- scheelite +/- biotite +/- gold), and (4) late ore stage S4 (calcite + ankerite +/- quartz +/- sulfide). Associated hydrothermal alterations in wall rocks are dominated by albitization (S1), silicification (S1 to S4), sericitization (S2), sulfidation (S2 to S3), and carbonatization (S4), with minor biotitization (S3) developed locally. Gold mineralization was primarily occurred in S2 stage with intensive silicification, sericitization, and sulfidation in metamorphic wall rocks, and occurred to a lesser extent in S3 stage with weak alteration possibly due to fairly weak activity and small fluxes of the ore fluids.