湘东北石炭系石英砂岩矿物组成、地球化学特征及沉积环境分析  

Analysis of mineral composition,geochemical characteristics and sedimentary environment of carboniferous quartz sandstone in Northeast Hunan Province

作　　者：刘守林 文亭 张雄 汤贺军 刘鹤群 王武 阚靖 刘一帆 Liu Shoulin;Wen Ting;Zhang Xiong;Tang Hejun;Liu Hequn;Wang Wu;Kan Jing;Liu Yifan(Geological Bureau of Hunan Province,Changsha 410014;Survey and Monitoring Institute of Hydrogeology and Environmental Geology of Hunan Province,Changsha 410014;Chinese Academy of Geological Sciences,Beijing 100037;College of Life Science and Chemistry,Hunan University of Technology,Zhuzhou,Hunan 412000;Qingdao Research Institute of Marine Geology of China Geological Survey,Qingdao,Shandong 266237)

机构地区：[1]湖南省地质院,长沙410014 [2]湖南省水文地质环境地质调查监测所,长沙410014 [3]中国地质科学院,北京100037 [4]湖南工业大学生命科学与化学学院,湖南株洲412000 [5]中国地质调查局青岛海洋地质研究所,山东青岛266237

出　　处：《地质科学》2024年第4期971-990,共20页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：湖南省地质院科技项目(编号:HNGSTP202103,HNGSTP202327);湖南省地质勘查基金项目资助。

摘　　要：为了了解湖南省石炭系石英砂岩的矿物组成、成矿沉积环境和成矿过程,本文以湘东北浦口-李畋地区石炭系石英砂岩为研究对象,将研究区内石英砂岩进行了分类,对不同类型的石英砂岩的矿物组成和石英包裹体特征进行了剖析,利用CM图型法和萨胡函数法对区内的颗粒级配进行了分析;最后,对石英砂岩的常量元素进行了分析。结果表明,中粒石英砂岩的SiO_(2)含量平均为98.54%,Al_(2)O_(3)含量平均为0.905%,Fe_(2)O_(3)含量平均为0.147%,杂质元素Al、Fe以白云母、黏土、赤铁矿、褐铁矿、钛铁矿矿物产出,偶见独居石、金红石等其他矿物。石英砂岩中石英包裹体数量较少,大小为0.8~2.5µm。研究区为河流三角洲沉积趋于浊流沉积,石英颗粒搬运方式以滚动为主,水动力条件一般。根据石英砂岩的地球化学特征表明该区砂岩属于典型的石英砂岩。研究区内中细粒石英砂岩的硅质成分纯度较高,杂质矿物少。石英砂岩碎屑来源于富含石英质的沉积岩物源区,并非来源于花岗岩的风化。区域内出露的冷家溪群变质砂岩和泥盆系石英砂岩,可能为该区提供了丰富的石英砂来源。In order to understand the mineral composition,ore-forming sedimentary environment and ore-forming process of carboniferous quartz sandstone,this paper classifies the quartz sandstone from Pukou-Litian district in Northeast Hunan Province and analyzes its mineral composition and quartz inclusion characteristics,CM pattern and Sahu function method are used to analyze the particle gradation.The geochemical characteristics of quartz sandstone are illustrated by major elements.The results show that the average contents of SiO_(2),Al_(2)O_(3)and Fe_(2)O_(3)are 98.54%,0.905%and 0.147%.The impurity elements of Al and Fe are mainly muscovite,clay,hematite,limonite and ilmenite,occasionally seen other minerals such as monazite and rutile.Fluid inclusions in quartz sandstone are very few with sizes of 0.8~2.5µm.The depositional environment is river delta,the particle transport method in quartz sandstone is mainly rolling with partial suspension,and the hydrodynamic conditions are general.According to the geochemical characteristics of quartz sandstone,the sandstone in this area belongs to typical quartz sandstone.The siliceous composition of the medium-fine quartz sandstone is high in purity and the impurity minerals are few.The quartz sandstone may be derived from the clastic material in the passive continental margin environment and the quartz-rich sedimentary rock source area.The metamorphic sandstones and Devonian quartz sandstones of Lengjiaxi Group in Mesoproterozoic have provided abundant quartz sand and gravel in this area.The quartz sandstone in this area is a multi-cycle sediment with high maturity.

关 键 词：沉积环境 地球化学特征 矿物组成 石英砂岩 石炭系 湘东北 

分 类 号：P619.233[天文地球—矿床学]