| 杜 蔺.贵州道真新民铝土矿床成矿机理[J].地质与勘探,2020,56(6):1116-1133 |
| 贵州道真新民铝土矿床成矿机理 |
| Metallogenic mechanism of the Xinmin bauxite deposit in Daozhen, Guizhou Province |
| 投稿时间：2020-03-11 修订日期：2020-08-05 |
| DOI：10.12134/j.dzykt.2020.06.002 |
| 中文关键词: 铝土矿 成矿物质来源 成矿环境 成矿地质作用 新民 贵州 |
| 英文关键词: bauxite, source of metallogenic material,ore-forming environment, metallogenic process, Xinmin, Guizhou |
| 基金项目:国家自然科学基金项目（编号：U1812402）资助 |
|
| 摘要点击次数: 2004 |
| 全文下载次数: 734 |
| 中文摘要: |
| 为深入探讨贵州道真新民铝土矿床的成矿物质来源、成矿环境及成矿地质作用，并建立成矿地质作用模型,本文对研究区地质特征及含铝岩系、底板黄龙组、韩家店组岩（矿）石的地球化学特征进行研究。研究结果表明：铝土矿Al2O3、TiO2、Ga/Al2O3含量与韩家店组泥页岩非常接近，含铝岩系稀土元素总量、配分曲线及δEu与韩家店组泥页岩最为接近，Zr-Cr-Ga三角图解显示该矿床含铝岩系与韩家店泥页岩分布位置接近，均落于中性或泥质母岩区；含铝岩系MnO/TiO2比值低，Ga含量高，Sr/Ba值低，显示矿床形成于陆相沉积环境，V/Zr值显示矿床具有海相沉积特征；含铝岩系具Ce正异常，Th/U值介于2～7之间，Be含量低，表明研究区铝土矿经历了风化作用、沉积作用；研究区铝土矿中的一水铝石是由三水铝石演化而成，经历了成岩后生压实脱水作用；通过研究区地表矿石与深部矿石主要化学成分对比，说明铝土矿经历后期表生淋滤作用。综合矿床地质地球化学特征，认为新民铝土矿成矿物质来源于下伏韩家店组泥页岩；成矿环境为陆相河湖环境，其沉积时曾有海水侵入；母岩演化为铝土矿的过程经历风化作用、搬运沉积作用、成岩后生作用、后期表生作用等一系列成矿地质作用。 |
| 英文摘要: |
| This work attempts to clarify the source of metallogenic material, metallogenic environment and metallogenic geological process of the Xinmin bauxite deposit in Daozhen, Guizhou, and to establish a metallogenic geological model. It builds on the geological features of the study area and geochemical characteristics of aluminium-bearing rocks in Huanglong Formation and Hanjiadian Formation. Results show that the contents of Al2O3, TiO2 and Ga/Al2O3 in bauxite are very close to those in the mud shale of Hanjiadian Formation, and the total amount of rare earth elements, distribution curve and Eu in the aluminium-bearing rocks are the closest to those in the mud shale of Hanjiadian Formation. The Zr-Cr-Ga triangle diagram indicates that the aluminum-bearing rock series of the deposit is close to the Hanjiadian mud shale and falls in the intermediate or argillaceous parent rock area. The low MnO/TiO2 ratio, high Ga content and low Sr/Ba value indicate that the deposit formed in a continental sedimentary environment, while the V/Zr value indicates that the deposit has marine sedimentary characteristics. The aluminium-bearing rocks have positive Ce anomalies, with Th/U values of 2 ～ 7 and low Be content, implying that the bauxite in the study area has undergone weathering and sedimentation. The diaspore in bauxite in the study area evolved from gibbsite and has undergone diagenetic epigenetic compaction and dehydration. Comparison of the main chemical compositions of the surface ore and the deep ore in the study area suggests that the bauxite experienced epigenetic leaching in the later period. Integrating geological and geochemical characteristics of the deposit, this study suggests that the metallogenic material of the Xinmin bauxite was originated from the mud shale of the underlying Hanjiadian Formation. The metallogenic process occurred in a continental river and lake setting. The evolution of parent rock into bauxite has undergone a series of metallogenic geological processes, including weathering, transport, sedimentation, diagenesis and epigenesist in the later period. |
|
查看全文
查看/发表评论 下载PDF阅读器 |
| 关闭 |
|
|
|
