贵州从江九星铁矿床成矿流体研究

发布时间：2018-06-04 11:08

  本文选题：成矿流体 + 流体包裹体　； 参考：《贵州大学》2015年硕士论文

【摘要】：九星铁矿床位于贵州省从江九星地区,其大地构造位置为江南古陆西南缘,即位于扬子地台和华南褶皱带之间的过渡带,区域构造上历经了武陵期、加里东期、印支期、燕山期、喜马拉雅期多期次构造运动。区域上出露的地层主要为新元古界四堡岩群文通岩组(Pt3w)、唐柳岩组(Pt3t)以及新元古界青白口系下江群甲路组(Qbj)、乌叶组(Qbw)、番召组(Qbf)。本文在前人的研究基础之上,对九星铁矿床开展了较系统的矿床地质和成矿流体地球化学研究,获得了成矿流体性质和来源特征,并探讨成矿流体在九星铁矿床的形成过程中的作用和意义。取得了如下主要成果:(1)成矿具有多期次作用特点,主要可分为区域变质成矿期、热液成矿期和表生成矿期。(2)热液成矿期石英流体包裹体岩相学观察,富液体包裹体最为发育,主要为NaCl-H2O溶液。(3)流体包裹体测温学表明,成矿流体盐度为0.71~21.61wt%(NaCl eqv),均值为13.40wt%(NaCl eqv),是中等盐度流体;均一温度为108~383℃,均值为220℃,是中温流体;成矿压力为8.9~46.9MPa,均值为24.37MPa;成矿深度为0.35~1.56Km,均值为0.90Km,是浅成成矿深度。(4)单个流体包裹体成分的激光拉曼光谱原位成分分析表明,包裹体液相成分主要是H2O,其次是N2和CO2,气相成分主要是H2O、N2和CO2。(5)成矿流体H同位素组成为水为-101.5~-89.0‰。石英中O同位素石英为10.2~10.8‰,经过计算得出流体O同位素组成水为-1.16~1.24‰,均值为-0.18‰。H-O同位素组成特征表明,氧具有漂移特征,表明流体多来源特征。综上所述,九星铁矿床流体的成矿作用机制较为复杂,矿体是在有利的区域变质作用、地层、岩性、构造条件下,流体对成矿物质的活化、转移并在适宜成矿环境富集沉淀而形成。
[Abstract]:The Jiuxing iron deposit is located in the Jiangjiuxing area, Guizhou Province. Its tectonic location is the southwestern margin of the Yangtze ancient land, that is, the transitional zone between the Yangtze platform and the South China fold belt. The regional structure has gone through the Wuling, Caledonian and Indosinian periods. Yanshanian period, Himalayan stage multiple times tectonic movement. The strata exposed in the region are mainly composed of Pt3WN and Pt3t of the Neoproterozoic Sibao Group, and the Lower Jiangqun Group of the Neoproterozoic Qingbakou formation, the Lower Jiangqun Road formation of the Neoproterozoic, the Wuye formation and the Panzhao formation. Based on the previous studies, a systematic study of ore deposit geology and ore-forming fluid geochemistry has been carried out in this paper, and the ore-forming fluid properties and source characteristics have been obtained. The role and significance of ore-forming fluid in the formation of Jiuxing iron deposit are also discussed. The main results obtained are as follows: the ore-forming stage has the characteristics of multiple stages, which can be divided into regional metamorphic metallogenic period, hydrothermal metallogenic stage and epigenetic ore forming stage. (2) the petrographic observation of quartz fluid inclusions in hydrothermal metallogenic period shows that liquid rich inclusions are the most developed. The temperature measurement of fluid inclusions mainly in NaCl-H2O solution shows that the salinity of ore-forming fluid is 0.71~21.61wt%(NaCl eqvn, the mean value is 13.40wt%(NaCl eqvn, which is medium salinity fluid, the homogenization temperature is 108 ~ 383 鈩，

本文编号：1977140