苏里南Saramacca金矿床地质和地球化学特征  

Geological and geochemical characteristics of Saramacca gold deposit in Suriname

作　　者：赵路通 林亮华 ZHAO Lutong;LIN Lianghua(Sino-Zijin Resources Co.,Ltd.,Zijin Mining,Beijing 100012,China;Rosebel Gold Mines N.V.Paramaribo box2973,Suriname)

机构地区：[1]中色紫金地质勘查(北京)有限责任公司,北京100012 [2]苏里南罗斯贝尔金矿有限公司,帕拉马里博Box2973

出　　处：《矿产勘查》2025年第1期166-174,共9页Mineral Exploration

基　　金：紫金矿业集团科技立项项目矿山综合找矿预测专项(4104KY2022030001)资助。

摘　　要：Saramacca大型造山型金矿床位于圭亚那地盾北部,矿体赋存于Marowijine绿岩带变质玄武岩中并受构造破碎带控制。本文对赋矿玄武质围岩开展的岩石地球化学研究表明,矿区玄武岩的K_(2)O+N_(2)O含量(1.83%~4.28%)较低,N_(2)O/K_(2)O为2.0~263,相对富Na贫K,MgO(5.08%~8.12%)含量中等,全铁(11.42%~13.75%)含量较高,属于高镁拉斑玄武岩。玄武岩具平坦的稀土元素配分模式,轻、重稀土分异较弱,总体上缺乏元素Eu、Sr、P、Ti和高场强元素Nb、Ta的亏损,与洋底高原玄武岩相似,Zr-Y-Nb-Th元素进一步构造判别显示矿区玄武岩源区与地幔柱有关。结合区域构造演化分析,矿区玄武岩形成于泛亚马逊造山期D1阶段洋壳俯冲之前。与其他绿岩带中发育高原玄武岩的超大型Au矿集区比较可知,高Au含量的与地幔柱有关玄武岩的先期存在可能是这些地区发生超大规模Au富集成矿的重要原因之一。The Saramacca large orogenic gold deposit is located in the northern part of the Guyana Shield,where the ore body is hosted in metamorphic basalts of the Marowijine Greenstone Belt and is controlled by tectonic fracture zones.In this paper,the rock geochemical study of ore-bearing basaltic surrounding rocks shows that the content of K_(2)O+N_(2)O in the basalt in the mining area is low(1.83%-4.28%),N_(2)O/K_(2)O is ranged from 2.0 to 263,rela⁃tively rich in Na and poor in K,medium in MgO(5.08%-8.12%)and high in total iron(11.42%-13.75%),which be⁃longs to high-magnesium tholeiite.Basalt has a flat distribution pattern of rare earth elements,with weak differentiation between light and heavy rare earth elements,and generally lacks the loss of elements Eu,Sr,P,Ti and high field strength elements Nb and Ta,which is similar to the basalt on the ocean floor plateau,further discrimination of Zr-Y-Nb-Th element structure shows that the source area of basalt in the mining area is related to mantle plume.Combined with the analysis of regional tectonic evolution,basalt in the mining area was formed before the subduc⁃tion of oceanic crust in D1 stage of Pan-Asian Amazon orogeny.Compared with the super-large Au ore concentra⁃tion areas where plateau basalts are developed in other greenstone belts,it can be seen that the pre-existence of ba⁃salts related to mantle plume with high Au content may be one of the important reasons for the super-large Au en⁃richment in these areas.

关 键 词：Saramacca金矿床 圭亚那地盾 绿岩带 造山型金矿 洋底高原玄武岩 

分 类 号：P548[天文地球—构造地质学]