永梅凹陷带铁多金属矿成矿特征与找矿方向

通过对永梅凹陷带内铁多金属矿床的赋矿层位、沉积特征、成矿物质来源以及燕山期中—酸性岩浆活动的叠加—改造作用进行研究,探讨了矿床成因和找矿方向。结果表明:1永梅凹陷带内铁多金属矿的赋矿层位以经畲组下部为主,其次为栖霞组上部,铁质主要来源于海相火山作用;2铅、锌、钨、锡等金属元素具有沉积和岩浆双来源;3燕山期中—酸性岩浆活动对铁多金属元素具有活化转移和叠加富集作用,空间上形成了铁-钼、铁-铅-锌多金属矿。基于上述结论,认为区内马坑式铁矿是海相火山沉积-岩浆热液叠加改造形成的,该区下一步找矿方向应为凹陷带东南部梅县玉水—龙岩马坑—德化阳山一线的超壳断裂带两侧,对于区内找矿工作具有一定的参考价值。

Prospecting Direction and Metallogenic Characteristics of Iron Polymetallic Ore in Yong'an-Meizhou Depression Belt

The genesis and prospecting direction of the iron polymetallic deposits located in the Yong'an-Meizhou depression belt are discussed by analyzing the ore-bearing stratum,sedimentary characteristics,ore-forming material sources and the superimposition and reworking process caused by the Yanshanian intermediate-acidic magmatism of the iron polymetallic deposits located in the Yong'an-Meizhou depression belt.The research results show that:①the lower Jingshe formation dominates major ore-bearing stratum of the iron polymetallic deposits,followed by the upper Qixia formation,iron is mainly derived from submarine volcanism;②Pb,Zn,W,Sn and other metal elements derive from both sedimentation and magmatism;③the iron polymetallic elements are remobilized，superimposed and enriched by the intermediate-acidic magmatism intrusions of Yanshanian，spatially forming the Fe-Mo and Fe-Pb-Zn polymetallic ore.Based on the above analysis results，it is considered that the ore-genesis of Makeng-type iron deposit is marine volcanic sedimentation-magmatic hydrothermal superimposition，the ore-prospecting should be oriented on both sides of ultra-crustal faults zone along Yushui-Makeng-Yangshan in the southeast Yong'an-Meizhou depression belt，therefore，it can provide some reference for the prospecting work in the research region.