胶西北金矿集区基于超壳走滑断裂构造体系的金成矿机制探讨——来自深反射地震探测的证据

Study on Gold Mineralization Mechanism Based on Transcrust Strike-slip Fault Structural System in Jiaoxi Gold Concentrating Area--Evidence from Deep Reflection Seismic Exploration

地壳结构是认识成矿系统和开展深部找矿预测的重要基础,是正确揭示胶西北地区中生代大规模、短时限、高强度的金成矿大爆发机制的金钥匙。为了准确掌握胶西北金成矿系统深部结构,本团队先后在胶西北地区实施了海量深反射地震、大地电磁和重力剖面工程及深度3266 m深钻探工程,获得横跨胶西北金矿集区三山岛-焦家-招平三条主成矿带的深部探测剖面,精确揭示了胶西北地区深部地质结构,三山岛断裂带与焦家断裂带深部呈反“y”字型交会,发现了板块俯冲挤压引起的大型超壳走滑断裂及莫霍面破裂,建立基于超壳走滑断裂构造体系的巨量金成因模式。本项工作对于进一步深化胶西北金矿集区巨量金成矿作用机制和成矿模式的认识,丰富和完善胶东金矿成矿理论具有重要意义。

The crustal structure is an important foundation for understanding the ore-forming system and conducting deep ore exploration and prediction.It is also the gold key to correctly understanding the mechanism of large scale,short term and high intensity gold mineralization in the northwest Jiaozhou area during the Mesozoic era.In order to accurately grasp the deep structure of the gold mineralization system in the northwest of Jiaodong area,massive deep reflection seismic,magnetotelluric and gravity profile engineering,as well as a series of 2200~3200m deep drilling projects have been carried out in the northwest of Jiaodong area.Deep exploration profiles spanning the three main mineralization zones of Sanshandao—Jiaojia—Zhaoping in the northwest of Jiaodong area have been obtained.Deep geological structures in the northwest of Jiaodong have been accurately revealed.Sanshandao fault zone intersects with Jiaojia fault zone in a reverse"y"shape in the deep part,and large scale transcrustral strike-slip faults and Moho surface fractures caused by plate subduction and compression have been discovered.A massive gold genesis model based on transcrust strike-slip fault structural system has been established.This work is of great significance for further deepening the understanding of the mechanism and ore-forming model of massive gold mineralization in the northwest Jiaodong gold mining area,and enriching and improving the ore-forming theory of Jiaodong gold deposits.