赣西北花山洞钨矿隐伏花岗岩地球化学特征及锆石U-Pb定年分析

发布时间：2018-03-22 12:15

本文选题：赣西北　切入点：花山洞钨矿　出处：《中国地质大学(北京)》2015年硕士论文　论文类型：学位论文

【摘要】：近年来,江西省北部九岭地区相继发现了多个中大型钨锡多金属矿床,成为了重要的资源潜力区,花山洞矿区即为其中之一。本文研究分析了与赣西北花山洞钨矿有密切成因关系的花岗岩及矿区附近山口岩体的地球化学特征。岩石地球化学表明,岩石地球化学表明,这三种岩石均为钙碱性过铝质,富Na的花岗岩;且从山口岩体到黑云母花岗岩再到含白云母花岗岩,总体上Si O2含量增高,碱质增加,铝含量降低,铁镁含量降低,为正岩浆演化趋势。微量元素中,三种岩石均富集Rb、Tu、U、La、Nd等大离子亲石元素,亏损Ba、Nb、Ti、Sr、P等元素,具有大陆地壳的特征。含白云母花岗岩、黑云母花岗岩和山口岩体的Rb/Sr值分别为:0.98、1、0.63;Rb/Nb分别为20.8、22.9、17;显著高于中国东部上地壳的平均值和全球分平均值,Nb/Ta平均值分别为9.34、9.81、10.4,低于地壳平均值,暗示花岗质岩浆具有壳源特征。在成矿元素方面,含白云母花岗岩W、Sn平均含量显著高于黑云母花岗岩和山口岩体,说明含白云母花岗岩与成矿关系更为密切。三者总稀土含量均较低,且从含白云母花岗岩到黑云母花岗岩再到山口岩体稀土总量逐渐增加基本无δCe异常。在稀土配分型式图中可见稀土配分型式总体向右倾斜,为典型的‘I’型花岗岩特征。轻稀土分异较为明显;重稀土分异不明显。含白云母母花岗岩、黑云母花岗岩和山口岩体主量元素间存在过渡及正岩浆演化的趋势;微量元素比值蛛网图和稀土元素配分型式图颇为一致;形成时代接近;空间上紧邻;三者可能为同源分异岩浆。含白云母花岗岩其LA-MICP-MS锆石U-Pb测年结果为807.1±8.2Ma,与前人测得的与白钨矿共生的辉钼矿Re-Os年龄极为接近,故该期花岗岩为成矿岩体。结合有关区域背景资料和前人研究成果可知,与花山洞钨矿有关的花岗岩形成于新元古代,源区物质除中元古代地壳物质以外,有一定新生地幔物质的加入,其形成的构造背景为岛弧碰撞后拉张环境。此次分析表明该矿床成矿作用与晋宁期岩浆作用有关,该发现不仅为赣北甚至整个华南地区钨矿的研究提供新的思路和方向,而且对华南钨矿多期次成矿作用研究及找矿实践具有重要指导意义。
[Abstract]:In recent years, Jiangxi Province North Ridge nine have been found in a number of large tungsten tin polymetallic deposit, become the important area of resource potential, Huashan hole mining is one of them. This paper analyzes the geochemical characteristics of granite mining area and has a close genetic relationship with the North cave near the mountain flower tungsten rock mass. Rock geochemistry shows that rock geochemistry shows that the three types of rocks are peraluminous calc alkaline, Na rich granite; and from the mountain rock to biotite granite to contain muscovite granite, increased the overall Si O2 content, alkali increase, decreasing the content of aluminum, iron and magnesium content is reduced, magma evolution trend of trace elements in three kinds of rocks are enriched in Rb, Tu, U, La, Nd and other large ion lithophile elements, Nb, Ti, loss of Ba, Sr, P and other elements, has the characteristics of continental crust. Containing muscovite granite, biotite granite and rock mountain The Rb/Sr values were: 0.98,1,0.63; Rb/Nb 20.8,22.9,17 respectively; significantly higher than the average China in the upper crust is the average and the world, the average value of Nb/Ta was 9.34,9.81,10.4, lower than the average value of the crust, suggesting that the granitic magma with crust. The metallogenic elements, including muscovite granite W, average Sn content significantly above the biotite granite and mountain rock, containing muscovite granite and mineralization more closely. Total content of rare earth three was low, and from muscovite granite to biotite granite to the mountain rock rare earth volume gradually increased. In the delta Ce no abnormal REE patterns seen with rare earth the overall model is skewed to the right, is a typical "I" type granites. LREE differentiation is obvious; hree is not obvious. With Muscovite parent granite, biotite granite and rock mountain There is transition and magma evolution trend of major elements; the spider diagram of trace element ratio and the REE distribution patterns is quite consistent; the formation age of near space; close to three were homologous; differentiation of muscovite granite magma. Containing the LA-MICP-MS zircon U-Pb dating results with the previous 807.1 + 8.2Ma. The measured and the Re-Os ages of Molybdenite scheelite symbiosis is very close to the granite ore rock. Combined with the regional background data and the previous research results, related to flower cave tungsten granite formed in Neoproterozoic, source materials except the Mesoproterozoic crustal material, has added new material in the mantle. The tectonic background for the formation of the arc after the collision extensional environment. The analysis shows that the mineralization and magma of Jinning period, which not only in North Southern China and even the whole area of tungsten The study of ore deposits provides new ideas and directions, and has important guiding significance for the study of the multiphase metallogenesis of Southern China tungsten ore and the practice of prospecting.

【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.67;P597.3

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