闽中东部地区金矿成矿规律综述与找矿方向研究探讨

A Review of Gold Mineralization Patterns and Discussion on Prospecting Directions in the Eastern Central Fujian Region

摘要: 本文是在前人工作的基础上系统阐述了闽中东部地区金矿的成矿规律，并探讨了具体的找矿方向。该区域位于环太平洋成矿带西缘，是晚中生代火山–岩浆弧的核心区域，其独特的“棋盘格”式构造格架为金矿成矿提供了优越的条件。区内金矿化主要形成于加里东期和燕山期两个重要成矿期，可划分为三大成因类型：造山型金矿(与剪切带/脆韧性剪切带相关)、浅成低温热液型金矿和岩浆热液型金矿，其中造山型金矿常伴有显著的构造蚀变。金矿成矿的控矿因素主要包括：NE向深大断裂与NW向断裂交汇形成的构造格架、环形火山机构、元古代地层和中生代火山岩系作为主要容矿围岩和金物质来源，以及燕山期花岗质岩浆活动提供的热源和流体改造。成矿流体为岩浆热液、变质流体和大气降水的多源混合，金主要以氯络合物和硫氢络合物形式迁移，流体混合、水岩反应和沸腾是金沉淀的关键机制。围岩蚀变以硅化、绢英岩化、粘土化和青磐岩化为主，形成同心环状分带，强硅化带与金品位呈正相关。主要找矿标志包括：Au-As-Sb-Hg (浅成低温热液型)地球化学异常、岩层低阻电性异常、重力梯度带、遥感识别的蚀变带以及特定的岩石结构构造。重点找矿区域有德化火山盆地、尤溪裂谷带、永泰构造转换带和仙游基底隆起区，这些区域均具备显著的成矿潜力。

Abstract: Based on previous studies, this paper systematically elaborates the gold mineralization patterns in the eastern central Fujian region and discusses specific prospecting directions. The region is located on the western margin of the Circum-Pacific metallogenic belt and represents the core area of the Late Mesozoic volcanic-magmatic arc, where the distinctive “chessboard-like” structural framework provides favorable conditions for gold mineralization. Gold mineralization in the area was primarily formed during two major metallogenic epochs: the Caledonian and Yanshanian periods, and can be classified into three genetic types: orogenic gold deposits (associated with shear zones/brittle-ductile shear zones), epithermal gold deposits, and magmatic-hydrothermal gold deposits, with orogenic gold deposits commonly accompanied by significant structural alteration. The ore-controlling factors for gold mineralization mainly include: the structural framework formed by the intersection of NE-trending deep-seated faults and NW-trending faults, ring-shaped volcanic structures, Proterozoic strata and Mesozoic volcanic rock series serving as the principal ore-hosting wall rocks and sources of gold material, as well as the heat source and fluid modification provided by Yanshanian granitic magmatic activity. The ore-forming fluids represent multi-source mixing of magmatic hydrothermal fluids, metamorphic fluids, and meteoric water, with gold primarily transported as chloride and bisulfide complexes. Fluid mixing, water-rock interaction, and boiling constitute the key mechanisms for gold precipitation. Wall-rock alteration is dominated by silicification, phyllic alteration, argillic alteration, and propylitic alteration, forming concentric zonal patterns, with intense silicification zones showing positive correlation with gold grades. Primary prospecting indicators include: Au-As-Sb-Hg (epithermal type) geochemical anomalies, low-resistivity electrical anomalies in rock formations, gravity gradient zones, remotely sensed alteration zones, and specific rock structural features. Priority prospecting areas include the Dehua volcanic basin, Youxi rift zone, Yongtai structural transition zone, and Xianyou basement uplift area, all of which demonstrate significant metallogenic potential.