| 赣中大王山钨多金属矿床流体包裹体及 H-O-S 同位素特征 |
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| 引用本文： | 杨庆坤,宣璞琰,张小亮,周万蓬,曲宏健.赣中大王山钨多金属矿床流体包裹体及 H-O-S 同位素特征[J].地质科学,2017,0(4):1282-1296. |
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| 作者姓名： | 杨庆坤 宣璞琰 张小亮 周万蓬 曲宏健 |
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| 作者单位： | 东华理工大学放射性地质与勘探技术国防重点学科实验室 南昌 330013;东华理工大学 地球科学学院 南昌 330013;中国地质大学（北京）地球科学与资源学院 北京 100083 |
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| 摘 要： | 为确定赣中大王山钨多金属矿床成因类型及地质特征， 笔者对主成矿期石英和硫化矿物进行了流体包裹体、H-O-S 同位素研究。 结合野外矿体产出形态， 可以将研究区划分出3 期成矿作用， 早期以矿囊状为特征， 与围岩无明显的蚀变现象， 主成矿期为大脉状， 与围岩发生云英岩化， 成矿晚期可见含矿石英晶洞。 主成矿期包裹体岩相学和显微测温结果显示： 石英中主要发育气液二相包裹体、富气相包裹体、CO2三相包裹体和气-液-固三相包裹体 ； 包裹体均一温度为 180 ℃ ～280 ℃（峰值为190 ℃ ～210 ℃）， 盐度为7.86% ～20.22% NaCleqv （峰值为11%～17% NaCleqv ）， 结合前人对赣中石英脉型黑钨矿中的黑钨矿测温结果， 推测大王山形成于中温、中高盐度；石英包裹体δDV-SMOW 值介于- 93.1‰～-72.5‰， δ18OH2O 值介于0.9‰～3.4‰， 石英包裹体的温度-盐度关系图显示成矿流体混入了低温、低盐度的流体相；δ34S 值介于-1.3‰～+1.9‰之间， 表明成矿物质硫源主要来自深源岩浆。 结合前人研究显示， 黑钨矿较石英早结晶， 成矿流体以岩浆水为主， 大气降水参与成矿， 硫源与深部岩浆有关。 赋矿碱长花岗岩中见有W-Mo 多金属矿囊和细晶岩、伟晶岩脉， 其成岩时间和成矿时间一致。 指示了大王山钨多金属与围岩碱长花岗岩具有一定的亲源性， 并且岩浆-流体液态不混溶作用是导致W-Mo 多金属矿沉淀的主因。
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| 关 键 词： | 钨多金属矿床 流体包裹体 液态不混溶作用 大王山 |
| 收稿时间： | 2017-03-29 |
| 修稿时间： | 2017-03-29; |
Immiscibility and mineralization of Dawangshan tungsten polymetallic deposit,central Jiangxi Province |
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| Yang Qingkun Xuan Puyan Zhang Xiaoliang Zhou Wanpeng Qu Hongjian.Immiscibility and mineralization of Dawangshan tungsten polymetallic deposit,central Jiangxi Province[J].Chinese Journal of Geology,2017,0(4):1282-1296. |
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| Authors: | Yang Qingkun Xuan Puyan Zhang Xiaoliang Zhou Wanpeng Qu Hongjian |
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| Institution: | Fundamental Science on Radioactive Geology and Exploration Technology Laboratory, East China University of Technology, Nanchang 330013;School of Earth Sciences, East China University of Technology, Nanchang 330013;School of Earth Sciences and Resources, China University of Geosciences, Beijng 100083 |
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| Abstract: | The fluid inclusions and H-O-S isotopes of ore-stage quartz and sulfide are studied in order to determine the genetic type and geological characteristics of tungsten polymetallic deposit of Dawangshan in the central Jiangxi Province. Combined with field orebody shape, the study area can be divided into three stages of mineralization, there were some ore pockets in early mineralization stage, no obvious alteration phenomenon with the surrounding rock, the main mineralization stage is the large veins, the surrounding rock occurred greisenization, in the late stage, there were ore minerals in quartz geodes. The results of fluid inclusion petrography and microthermometry showed that the quartz mainly contain gas-liquid inclusions, vapor-rich inclusions, CO2three phase inclusion and gas-liquid-solid three-phase inclusion; The homogenization temperature of fluid inclusions is 180 ℃ ～280 ℃（peak is 190 ℃ ～210 ℃）, salinity is 7.86% ～20.22% NaCleqv （peak is 11% ～17% NaCleqv ）, belonging to the moderate temperature, and moderate-high salinity deposit; The δDV-SMOW values of quartz inclusions is -93.1‰～-72.5‰, the δ18OH2O values is 0.9‰～3.4‰, as can be seen from the temperature-salinity graph of quartz inclusions, ore-forming fluid was mixed with fluid phase of low temperature and low salinity; The δ34S values of sulfide range from -1.3‰ to +1.9‰, shows that sulfur mainly derived from deep magma sources. Combined with previous researches, the crystallization time of wolframite is earlier than quartz’s, and the ore-forming fluids is magmatic water, but mixed with meteoric water. The W-Mo polymetallic ore capsule, aplite veins and pegmatite veins were found in the ore-hosting alkali feldspar granite, and the metallogenic time is consistented with the diagenetic time. By synthetic analysis, the tungsten polymetallic of Dawangshan have good affinity to surrounding rock of alkali feldspar granite, and the magma-liquid immiscibility is a major cause of precipitation of W-Mo polymetallic ore. |
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| Keywords: | Tungsten polymetallic deposit Fluid inclusion Immiscibility Dawangshan Mountain |
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