南秦岭石泉北部将军河地区中酸性岩脉锆石U-Pb年代学及其构造意义
发布时间：2019-06-02 17:14
【摘要】：南秦岭石泉北部中酸性岩脉发育,大部分岩脉与地层之间为构造接触关系,其形成时代及与区域金矿化的关系一直存在疑问。本研究采集石泉北部将军河地区中酸性岩脉13件,通过详细野外观察与室内鉴定,确定岩脉的岩性主要为闪长岩类。主量元素分析数据表明闪长岩的SiO_2含量为53.19%~68.48%,铝饱和指数A/CNK值为0.67~1.28,里特曼指数σ值介于1.4~2.93之间;微量元素分析数据表明中酸性闪长岩脉的稀土总量较低(ΣREE=44.54×10~(-6)~253.23×10~(-6)),REE球粒陨石标准化图呈轻、重稀土高度分馏的右倾型(HREE/LREE=6.15~14.87,(La/Yb)_N=5.97~38.67),具有弱负Eu异常(δEu=0.68~0.88);微量元素蛛网图显示富集大离子亲石元素(Ba、K、Sr)与高场强元素(Zr、Hf),相对亏损高场强元素(HREE、Ti、P、Th),岩脉可能来自于与消减作用有关的下地壳物质重熔。闪长岩脉的单颗粒锆石U-Pb年龄为771.9±3.4Ma,与汉南杂岩、安康北部的凤凰山内新元古代的岩浆活动具有同步性,指示区域伸展裂解的构造背景。根据野外填图推测南秦岭石泉北部将军河地区新元古代的岩脉对金矿的形成没有直接关系。
[Abstract]:The middle-acid veins in the north of Shi Quan in the southern Qinling Mountains are developed, and most of the veins are in contact with strata. The formation age of the veins and the relationship between them and regional gold mineralization have always been in doubt. In this study, 13 intermediate-acid veins in Jianguhe area, northern Shi Quan, were collected. Through detailed field observation and laboratory identification, it was determined that the lithology of the veins was mainly diorite. The data of principal element analysis show that the SiO_2 content of diorite is 53.19% 鈮，
本文编号：2491292
[Abstract]:The middle-acid veins in the north of Shi Quan in the southern Qinling Mountains are developed, and most of the veins are in contact with strata. The formation age of the veins and the relationship between them and regional gold mineralization have always been in doubt. In this study, 13 intermediate-acid veins in Jianguhe area, northern Shi Quan, were collected. Through detailed field observation and laboratory identification, it was determined that the lithology of the veins was mainly diorite. The data of principal element analysis show that the SiO_2 content of diorite is 53.19% 鈮，
本文编号：2491292
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