南海东部表层沉积物中普通角闪石和磁铁矿的特征及其成因  

MINERAL CHARACTERISTICS OF HORNBLENDE AND MAGNETITE IN SURFACE SEDIMENTS IN THE EAST OF THE SOUTH CHINA SEA AND THEIR GENESIS

作　　者：杨群慧[1] 林振宏[2] 张富元[3] 周怀阳[1] 

机构地区：[1]中国科学院广州地球化学研究所,广州510640 [2]中国海洋大学海洋地球科学学院,青岛266003 [3]国家海洋局海底科学重点实验室,杭州310012

出　　处：《海洋地质与第四纪地质》2004年第2期29-35,共7页Marine Geology & Quaternary Geology

基　　金：国家重点基础研究发展规划项目(G200007850);中国科学院广州地球化学研究所知识创新工程领域前沿资助项目(GIGCX 03 07);国家海洋局海底科学重点实验室基金资助课题(2001 2)

摘　　要：采用电子探针测试技术和晶体化学 成因分类图解法对南海东部表层沉积物中普通角闪石和磁铁矿的化学成分进行研究,结果表明,普通角闪石属于钙质角闪石组,主要类型有镁角闪石、钙镁闪石质角闪石、镁绿钙闪石质角闪石、浅闪石质角闪石、铁闪石质角闪石,均为中酸性岩浆成因。磁铁矿化学成分中TiO2、V2O5、Al2O3、MnO、MgO等标型组分的含量与岩浆成因的磁铁矿相似,其成因图解表明既有中酸性岩浆成因的也有基性岩浆成因的磁铁矿。普通角闪石和磁铁矿的成因性质与其共存的矿物特征和研究区的区域地质背景相吻合。Chemical composition of hornblende and magnetite in the surface sediments in the east of the South China Sea is studied by means of the electron microprobe analyses and crystallochemistry-genesis illustration. It is demonstrated that all of hornblende samples belong to the calcic amphibole group, varying from Magnesio-Hornblende, Tschermakitic Hornblende, Magnesio-Hastingsitic Hornblende, Edenitic Hornblende to Ferro-Edenitic Hornblende. They are derived from the intermediate-acidic magmatogenetic deposits. Contents of TiO_(2),V_(2)O_(5),Al_(2)O_(3),MnO and MgO in magnetites resemble those from magmatogenic deposits. The crystallochemistry-genesis illustration shows that they are not only derived from the intermediate-acidic but also from the basic magmatogenic deposits. Genetic characteristics of both hornblende and magnetite in sediments are consistent with those of coexisting minerals as well as the geological background around the study area.

关 键 词：普通角闪石 磁铁矿 化学成分 成因 南海 表层沉积物 

分 类 号：P736.3[天文地球—海洋地质] P736.21[天文地球—海洋科学]