Abstract:
The Daliangzi lead-zinc deposit is one of the typical large-scale deposits in the southwestern Sichuan ore concentration area whose spatial distribution is strictly controlled by F
15 main control fault and the supporting secondary structure, which provide a favorable place for ore-forming fluid migration and mineral precipitation.Aiming at the core issues of the metallogenic tectonic system of the deposit, the F
15 main controlled fault and its ore-controlling effect, appling Mining Field Geomechanics Theory and Method, by analyzing the geometry, kinematics, mechanics, tectonic rocks, and tectonic stages of the dominant faults and combining geochemical research, it is considered that the F
15 main control fault has the characteristics of ore-conducting and ore-hosting during the metallogenic period.The main strike-slip-fault-fold structural combination(negative flower-like structure)is the main structural combination of this deposit.The F
15 main ore control fault obviously shows two stages of tectonic activity: In the early stage(middle late Indosinian to early Yanshanian), right strike-slip tensional to right tensional strike-slip structures were formed due to NW-SE trending principal compressive stress.In the late stage(middle late Yanshanian), the fault was transformed into left strike-slip to left strike-slip compressional due to NE-SW trending principal compressive stress.The main metallogenic structural system is the NE structural belt composed of the right strike-slip tensional to right tensional strike-slip structures and its derivation of a series of NWW-NW trending extensional faults, NE compressional fracture and NE trending SW side dipping main anticline.The combination of elements such as Zn-Pb-Cd-Sb-Hg-Ag-As related to lead-zinc mineralization and the combination of metallogenic elements such as Mo-Tl related to deep fluids are obviously enriched.The ore-forming fluids "penetration" along the F
15 ore-conducting structure, and "penetrates"-metasomatism occurs in the structural system along the secondary NWW-NW-trending faults and the NE-trending SW-trending main anticlines and interlayer faults.This study is not only of practical significance to the deep and peripheral prospecting of Daliangzi lead-zinc mine, but also of scientific value to the study of the structural ore control law of the lead-zinc polymetallic ore concentration area in the southwestern Sichuan.