坦桑尼亚莫罗戈罗地区班巴拉维石墨矿地球化学特征及成矿研究  

Geochemical characteristics and metallogenic study of the Bambarawe graphite deposit in Morogoro,Tanzania

作　　者：曹义甲[1] 祁东[1] 张冬霞 柴丽洁 焦杨 CAO Yi-jia;QI Dong;ZHANG Dong-xia;CHAI Li-jie;JIAO Yang(No.2 Institute of Geological & Mineral Resources Survey of Henan, Zhengzhou 450001;Institute of Surveying Mapping and Geoinformation of Henan, Zhengzhou 450006)

机构地区：[1]河南省地质矿产勘查开发局第二地质矿产调查院,郑州450001 [2]河南省地质矿产勘查开发局测绘地理信息院,郑州450006

出　　处：《矿产勘查》2019年第2期333-343,共11页Mineral Exploration

基　　金：2016年度河南省财政地质勘查(国外)项目(编号:豫国土资发[2016]46号)资助

摘　　要：班巴拉维石墨矿主要赋存于元古宙乌萨迦兰超群鲁匡古勒组特戈特罗段的含石墨片麻岩中,含矿岩系为石墨黑云斜长片麻岩,中—粗粒鳞片状变晶结构,片麻状构造,矿石类型为大鳞片晶质石墨矿石。石墨矿石主量元素具有低硅、贫钙、富铝、富钾的特征;K_2O/Na_2O的平均值为6. 43,变质原岩表现出沉积岩的特征。LREE/HREE-∑REE呈正相关,表明其原岩可能为海相沉积;LREE/HREE-δEu呈正相关,反映了其壳源特征;并表现为弱的负Eu异常。根据地球化学原岩恢复图解投点,得出原岩可能为一套含碳质、富铝的泥质沉积建造,其物源为混合型物源,主要形成于被动大陆边缘。班巴拉维石墨矿的成矿物质来源主要为原岩中的有机碳,矿床成因属于区域变质矿床。The Bambarawe graphite deposit is hosted in the graphite bearing metamorphic rock series of the Usagaran Super Group Lukwangule Formation Tegetero Member. The ore bearing rock series is plagioclase gneiss containing graphite and biotite, the ore is medium to coarse scale flaky texture, gneiss structure, and ore type is large scale crystalline graphite ore. The main elements of the graphite ore are characterized by low silicon, poor calcium, aluminum rich and potassium rich. The average value of K2O/Na2O is 6.43, and the metamorphic protolith is characterized by sedimentary rocks. LREE/HREE-∑REE is positively correlated, indicating that its original rock may be marine sediments. LREE/HREE-δEu is positively correlated, reflecting its source characteristics and showing a weak negative Eu anomaly. According to the graphical input point of geochemical original rock recovery, it is concluded that the original rock may be a carbonaceous and aluminum rich argillaceous sedimentary formation. The provenance of metamorphic protolith is mixed source, mainly formed on the passive continental margin. The source of ore-forming material of the Bambarawe graphite deposit is mainly organic carbon in the original rock, and the genesis of the deposit belongs to the regional metamorphic deposit.

关 键 词：晶质石墨矿 地球化学特征 原岩恢复 矿床成因 坦桑尼亚 

分 类 号：P591[天文地球—地球化学] P611[天文地球—地质学]