{"title":"Ore-forming fluid characteristics and deposit genesis of the Songjianghe gold deposit in Dunhua, Jilin Province","authors":"Yufan Shi, Bile Li, Zhihua Li, Yaming Sun","doi":"10.1007/s12303-023-0038-1","DOIUrl":null,"url":null,"abstract":"<p>The Songjianghe gold deposit is located in the southeastern part of the Jiapigou–Haigou metallogenic belt, north of the North China Craton. The distribution of the ore body is governed by ductile shear zones and fractures oriented in the SN direction. The gold ore body consists of lenticular gold-bearing quartz veins. Mineralization can be divided into five stages: the quartz-oxidation stage (I), the pyrite-magnetite-quartz stage (II), the quartz-polymetallic sulfide stage (III), the telluride stage (IV), and the carbonate stage (V), with the main mineralization stages being III and IV. On the basis of lithological characteristics, three types of fluid inclusions were identified in the vein mineral assemblage: NaCl-H<sub>2</sub>O (W-type), CO<sub>2</sub>-H<sub>2</sub>O (C-type), and a minor amount of pure CO<sub>2</sub> (pc-type). W-type and C-type inclusions coexist randomly around natural gold minerals in the same quartz grain, indicating that the mineralizing fluid is heterogeneous. The mineralizing fluids had a medium temperature and low to medium salinity based on micro temperature measurements of various inclusions. During the main mineralization phase, H-O isotope tests indicate that the mineralizing fluids are mantle-driven and mixed with atmospheric precipitation during mineralization. δ<sup>34</sup>S data indicate that the mineralizing material originated from the mantle. The aforementioned characteristics suggest that Songjianghe is an orogenic gold deposit based on its dynamical background, with fluid immiscibility and sulfidation being the primary mechanisms of gold precipitation and enrichment.</p>","PeriodicalId":12659,"journal":{"name":"Geosciences Journal","volume":null,"pages":null},"PeriodicalIF":1.0000,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geosciences Journal","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1007/s12303-023-0038-1","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The Songjianghe gold deposit is located in the southeastern part of the Jiapigou–Haigou metallogenic belt, north of the North China Craton. The distribution of the ore body is governed by ductile shear zones and fractures oriented in the SN direction. The gold ore body consists of lenticular gold-bearing quartz veins. Mineralization can be divided into five stages: the quartz-oxidation stage (I), the pyrite-magnetite-quartz stage (II), the quartz-polymetallic sulfide stage (III), the telluride stage (IV), and the carbonate stage (V), with the main mineralization stages being III and IV. On the basis of lithological characteristics, three types of fluid inclusions were identified in the vein mineral assemblage: NaCl-H2O (W-type), CO2-H2O (C-type), and a minor amount of pure CO2 (pc-type). W-type and C-type inclusions coexist randomly around natural gold minerals in the same quartz grain, indicating that the mineralizing fluid is heterogeneous. The mineralizing fluids had a medium temperature and low to medium salinity based on micro temperature measurements of various inclusions. During the main mineralization phase, H-O isotope tests indicate that the mineralizing fluids are mantle-driven and mixed with atmospheric precipitation during mineralization. δ34S data indicate that the mineralizing material originated from the mantle. The aforementioned characteristics suggest that Songjianghe is an orogenic gold deposit based on its dynamical background, with fluid immiscibility and sulfidation being the primary mechanisms of gold precipitation and enrichment.
松江河金矿床位于华北克拉通以北的嘉皮沟-海沟成矿带东南部。矿体的分布受SN向韧性剪切带和断裂的控制。金矿体由透镜状含金石英脉组成。成矿作用可分为五个阶段:石英-氧化阶段(I)、黄铁矿-磁铁矿-石英阶段(II)、石英-多金属硫化物阶段(III)、碲化物阶段(IV)和碳酸盐阶段(V),其中主要成矿阶段为 III 和 IV 阶段。根据岩性特征,在矿脉矿物组合中确定了三种类型的流体包裹体:NaCl-H2O (W 型)、CO2-H2O(C 型)和少量纯 CO2(pc 型)。W 型和 C 型包裹体随机共存于同一石英颗粒中的天然金矿物周围,表明矿化流体是异质的。根据对各种包裹体的微温测量,矿化流体的温度为中等,盐度为中低。在主要成矿阶段,H-O 同位素测试表明成矿流体由地幔驱动,并在成矿过程中与大气沉淀混合。δ34S数据表明成矿物质来源于地幔。上述特征表明,根据其动力学背景,松江河是一个造山型金矿床,流体不溶性和硫化是金沉淀和富集的主要机制。
期刊介绍:
Geosciences Journal opens a new era for the publication of geoscientific research articles in English, covering geology, geophysics, geochemistry, paleontology, structural geology, mineralogy, petrology, stratigraphy, sedimentology, environmental geology, economic geology, petroleum geology, hydrogeology, remote sensing and planetary geology.