滇西北衙地区基于矿化类型及其分带的金多金属找矿预测

Gold polymetallic ore-prospecting prediction based on mineralization types and their zoning in Beiya area,western Yunnan Province

滇西北衙地区是云南乃至中国重要的Au多金属矿床集中区,近十余年来,区内Au多金属找矿勘查取得巨大进展。系统总结该区成矿规律和找矿勘查经验,实现已有矿区深边部和区域新的找矿突破是当前亟需解决的现实问题。根据典型矿床矿体赋存部位、控矿构造、容矿岩石、矿化蚀变、矿物组合、矿石结构构造、成矿时代、成矿作用、物探特征、化探特征等因素,文章总结了北衙式Au多金属矿床的矿化类型及分带特征,基于矿床系统的“源、运、储、变、保”演化过程,把控制因素和找矿标志与矿化类型之间互为标志相融合,建立了北衙式“五位一体”多类型矿体“全位”找矿预测模型。通过分析研究区地质、矿床(体)、物探、化探资料及其之间的演变和印证关系,文章进行“缺位”找矿预测,圈定了北衙北层间破碎带(岩性界面)型Pb-Zn-Ag(Au)矿(T_(1))、白莲村裂隙脉型Au矿(T_(2))、白莲村东红土型Au-Fe矿(T_(3))、老马涧斑岩型Au(Cu)矿(T_(4))、马头湾东矽卡岩型Au-Fe-Cu矿(T_(5))、干海子西矽卡岩型Fe-Au-Cu矿(T6)以及下山口原生矿(T7)共7个找矿预测区。

The Beiya area is an important gold-polymetallic ore concentration area in Yunnan and even the whole country,in which the potential of mineral resources is huge.In the present situation of bottleneck in prospecting for deeper part and broader area,how to adjust the train of thought to realize the new prospecting breakthrough in this area is an urgent question to be answered.Guided by the metallogenic series theory of ore deposits,this paper summarizes the mineralization types and their zoning pattern of the"Beiya-type"gold polymetallic deposits according to the typical ore-hosting location,ore-controlling structure,ore-hosting rock,mineralization/alteration,mineral association,ore texture and structure,mineralization age,metallogenesis,geophysical and geochemical characteristics and other factors.Based on the evolution process of"source,transport,storage,modification and preservation"of the ore deposit system,the paper integrates the control factors of different mineralization types and the ore-prospecting signs and mineralization signs to each other,and establishes the"location-integration"ore-prospecting prediction model which is called"five in one"Beiya style multi-type mineralization in this area.Through the analysis of geological,deposit(orebody),geophysical and geochemical data of the study area and their mutual evolution and verification relationship,the"location-vacancy"ore-prospecting prediction is made.Seven prospecting prediction areas are defined,including the Beiyabei fracture zone(lithologic interface)-type Pb-Zn-Ag(Au)(T_(1)),Bailiancun vein-type Au(Fe)(T_(2)),Bailiancundong laterite-type Au-Fe(T_(3)),Laomajian porphyry-type Au(Cu)(T_(4)),Matouwandong skarn-type Au-Fe-Cu(T_(5)),Ganhaizixi skarn-type Fe-Au-Cu(T_(6))and Xiashankou primary polymetallic mineralization(T_(7)).