云南墨江金厂矿床镍矿成因及找矿标志

Genesis and Prospecting Criteria of Nickel Deposit of Jinchang Deposit in MojiangCounty,Yunnan Province

墨江金厂矿床位于哀牢山金矿带中段,是三江成矿带上独有的金镍共生矿床。在详细的野外地质工作基础上,结合资料收集整理及室内综合研究,探讨了金厂镍矿床的矿床成因和找矿标志。研究结果表明:区内地质构造复杂,变质作用强烈,金厂矿床即是位于哀牢山浅变质带的独特金-镍矿床;金厂镍矿产于金厂岩体与浅变质围岩的接触带及蚀变带中,矿化受控于区域地质构造、矿源层、岩浆活动及岩性;镍矿(化)体与围岩为过渡关系,多与金矿(化)体在空间上分离,偶见穿插、重叠现象,形成略晚于金矿化,矿石类型包含石英浸染状黄铁矿型和绿色泥岩浸染状黄铁矿型2种,镍矿化总体属中低温热液矿化;深大断裂或燕山花岗岩活动带旁侧、超基性岩体旁侧、绿色水云母化泥岩等是寻找砷硫化镍矿的重要找矿标志。

TheMojiangJinchang deposit is located in the middle part of the Ailaoshan gold belt.It is a unique gold-nickel symbiotic deposit in the Sanjiang metallogenic belt.On the basis of detailed field geological work,combined with data collection and indoor comprehensive research,the genesis and prospecting criteria of Jinchang nickel deposit are discussed.The results show that the geological structure in the area is complex and the metamorphism is strong.The Jinchang deposit is a unique gold-nickel deposit located in the Ailaoshan shallow metamorphic belt.Jinchang nickel deposit is located in the contact zone and alteration zone between Jinchang rock mass and shallow metamorphic surrounding rock.The mineralization is controlled by regional geological structure,ore source layer,magmatic activity and lithology.The nickel ore(mineralized)body and the surrounding rock are in a transitional relationship,mostly separated from the gold ore(mineralized)body in space,occasionally interspersed and overlapped,and formed slightly later than the gold mineralization.The ore types include quartz disseminated pyrite type and green mudstone disseminated pyrite type.The nickel mineralization is generally a medium-low temperature hydrothermal mineralization.The deep fault or the side of the Yanshan granite active zone,the side of the ultrabasic rock mass,and the green hydromica mudstone are important prospecting indicators for the search for arsenic sulfide nickel deposits.