投稿时间：2023-08-08
修订日期：2024-05-13
网络发布日期：2024-06-26
中文摘要:湖南柿竹园矿田以矽卡岩型钨锡多金属矿床集中产出而闻名。近期在柴山矿区坑探新揭露了一组石英脉型钨矿体，该组矿体穿切早期矽卡岩，成矿明显较晚，这不仅为柿竹园深部找矿增添了新的线索，也为研究区内矽卡岩型钨矿与石英脉型钨矿的成因联系问题提供了理想场地。文章以柴山石英脉型钨矿为研究对象，对其中黑钨矿、白钨矿和石英开展了矿物地球化学和流体包裹体研究。结果显示：柴山黑钨矿表现为明显负Eu异常的左倾型稀土元素配分模式，与瑶岗仙黑钨矿类似；石英脉中白钨矿则表现为负Eu异常的平坦型稀土元素配分模式，这与区内矽卡岩型白钨矿类似，但分馏效应不明显，Mo含量也明显偏低；同一矿体中白钨矿的Y/Ho比值(6.21~22.35)明显高于黑钨矿的Y/Ho比值（4.61~5.95），这可能与晚期萤石的晶出有关。白钨矿和石英流体包裹体温度和盐度明显低于矽卡岩型钨矿，显示出中高温、中低盐度成矿流体特征。结合矿物学和流体包裹体的研究成果及矿体产出特征，指示柴山石英脉型钨矿与矽卡岩型钨矿为不同源、不同期次的岩浆热液产物，石英脉型钨矿的成矿流体可能源自柿竹园矿田千里山黑云母花岗岩主体侵位之后的更晚一期花岗质岩浆活动，并由此推测矿区南段深部存在一期更晚的岩浆成矿作用，成因上与石英脉型钨矿化相关，预测柿竹园矿田柴山矽卡岩型矿体之深部仍存“第二找矿空间”。
Abstract:The Shizhuyuan ore field in Hunan is well-known for its rich concentration of skarn-type tungsten-tin polymetallic deposits. Recent pit exploration at the Chaishan deposit has unveiled a group of newly discovered quartz vein-type tungsten ore body. The ore body intersects the early skarn, indicating a distinctly late mineralization phase. The discovery not only presents a novel clue for deep exploration in the Shizhuyuan ore field, but also offers an ideal location for investigating the genetic relationship between skarn-type tungsten ore and quartz vein-type tungsten ore in this region. This study investigates the mineral geochemistry and fluid inclusions of wolframite, scheelite, and quartz in the Chaishan quartz vein-type tungsten deposit. The results show that the Chaishan wolframite displays a left-inclin distribution pattern of REE with a noticeable negative Eu anomaly, similar to the geochemical characteristics observed in the wolframite of the Yaogangxian deposit. Scheelite found within quartz veins exhibits a flat REE distribution pattern with a negative Eu anomaly, which is similar to that of skarn-type scheelite in the surrounding area. However, there is no discernible fractionation effect, and the Mo content remains significantly low. The Y/Ho ratio of scheelite (ranging from 6.21 to 22.35) within the same ore body signi-ficantly surpasses that of wolframite (ranging from 4.61 to 5.95), a phenomenon likely attributable to the late-stage crystallization of fluorite. The temperature and salinity of fluid inclusions within scheelite and quartz notably differ from those observed in skarn-type tungsten deposits, exhibiting traits indicative of medium to high temperatures and medium to low salinity levels in the ore-forming fluids. Considering the findings from mineralogical studies, fluid inclusions analysis, and the ore body's occurrence features, it is inferred that the Chaishan quartz vein-type tungsten deposit and the skarn-type tungsten deposit are distinct magmatic hydrothermal formations originating from disparate sources and geological stages. The ore-forming fluid associated with the quartz vein-type tungsten deposit is postulated to originate from the later stages of granitic magmatism subsequent to the emplacement of the Qianlishan biotite granite in the Shizhuyuan ore field. It is conjectured there is a late-stage magmatic mineralization in the deeper regions of the southern section of the mining area, potentially interconnected with the quartz vein-type tungsten mineralization. It is anticipated that there exists untapped “second prospecting space” within the deeper sections of the Chaishan skarn-type ore body within the Shizhuyuan ore field.
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基金项目:本文得到国家重点研发计划项目(编号：2022YFC2905101)、国家自然科学基金地质联合基金重点项目(编号：U2344207)和国家自然科学基金(编号：41973046)联合资助
引用文本：
李陈浩,赵正,陈振宇,邓迪,李岩林.2024.湖南柿竹园矿田柴山石英脉型钨矿体的发现及其深部勘查指示[J].矿床地质,43(3):599~612LI ChenHao,ZHAO Zheng,CHEN ZhenYu,DENG Di,and LI YanLin.2024.Discovery of quartz vein-type tungsten ore body in Chaishan deposit of Shizhuyuan ore field, South Hunan and its indication for deep prospecting[J].Mineral Deposits43(3):599~612
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