河北承德大庙黑山钒钛磁铁矿床岩石地球化学特征  

Geochemistry of the Heishan V-Ti-bearing Magnetite Deposit in the Damiao Rocks of Chengde, Hebei Province

作　　者：江少卿[1,2,3] 郝梓国[1,3] 孙静[4] 王德忠[4] 许国新[4] 孟庆伟[3] 刘恋[3] 

机构地区：[1]中国地质大学地质过程与成矿作用国家重点实验室,北京100083 [2]中铝矿产资源有限公司,北京100082 [3]中国地质科学院矿产资源研究所,北京100037 [4]河北省地质矿产勘查开发局第四地质大队,河北承德067000

出　　处：《地质与勘探》2013年第3期458-468,共11页Geology and Exploration

基　　金：地质过程与矿产资源国家重点实验室开放课题"河北承德地区钒钛磁铁矿成矿作用研究"(编号GPMR0738);国家公益性行业科研专项项目"我国矿物种及系统矿物学研究"(编号:201011005)

摘　　要：河北承德大庙黑山铁矿床位于大庙斜长岩体南部边缘,大庙斜长岩体由黑山、马营、罗锅子沟岩体和大乌苏沟4个密切伴生的斜长岩和苏长岩体组成,其中钒钛磁铁矿体主要产于黑山苏长岩中。岩石地球化学研究表明,研究区内Mg#顺序依次为:超基性岩>苏长岩>斜长岩>磁铁矿石,反映基性岩浆侵入的时间稍晚于超基性岩。大庙斜长岩体、苏长-斜长岩体的各类型岩石中δ(Eu)具弱正异常,反映原始岩浆为碱性玄武岩浆的特征;轻稀土和大离子亲石元素富集,Ce/Pb比值高于地壳平均值,原始岩浆具有幔源特征,大庙斜长岩体产于板内拉张环境。苏长岩化学性质与矿床的形成有密切的关系:黑山、大乌苏沟两个岩体具有相同特征,苏长岩为镁质-镁铁质,富碱质,形成较富的铁、磷、钒、钛矿床;罗锅子沟岩体苏长岩富铁、钛,贫碱,形成的铁、磷、钒、钛矿床很贫或者只有矿化;马营岩体苏长岩富硅铝,贫碱,矿化很弱。The Heshan magnetite deposit is located in the southern margin of the Damiao plagioclase intrusions, which are comprised of four plagio-clase and nofite rock bodies： the Heishan, Maying, Luoguozigou and Dawusugou intrusions. The V - Ti - bearing magnetite ores mainly occur in the He-ishan norite intrusion. Geochemical studies show that the Mg# values for different rock types follow in a sequence of ultramMie rocks 〉 norite 〉 plagioclase 〉 magnetite ore rocks. This may suggest that the magnm-intruding age of marie rocks is later than the uhramafic rocks. The ~Eu values for the plagioelase and norite intrusions show weak positive anomalies, suggesting the original magmas are alkaline basalts. LREE and LILE are enriched ; the Ce/Ph ratio is higher than the mean value of crust ; the primitive magma show characters of a mantle source, and the Damiao plagioclase intrusions occur in an extension-al intraplate environment. The ehenfical properties of nofite is closely associated with the formation of this deposit. The Heishan and Dawusugou intrusions have the same characters, in which the norite is mafic-altramafic and alkali-rich, forming the iron, phosphorus, vanadium, and titatfium deposits. In the Luoguozigou intrnsion, the norite is Fe-and Ti-rich, and alkali-depleted, forming poor ores of iron, phosphorus, vanadium, and titanium, or only miner-alization. And in the Maying intrusion, the norite rock is alumina-rich and alkali-depleted with weak mineralization.

关 键 词：铁矿床 斜长岩 苏长岩 幔源 河北 

分 类 号：P612[天文地球—矿床学]