Discovery of Mg-righ volcanic rock series in western Altay area, Xinjiang and its geologic significance

查看全文 作　　者：Hecai [1]Niu;Jifeng [1]Xu;Xueyuan [1]Yu;Fanrong [1]Chen;Zouping [1]Zheng 机构地区：[1]Chinese Acad Sci, Guangzhou Inst Geochem, Canton 510640, Peoples R China 出　　处：《Chinese Science Bulletin》索引1999年第44卷第18期,共4页 摘　　要：A series of Mg-rich volcanic rocks, including rare Mg-rich dacites in the Asherle copper mine, western Altay Area, has been found. This suite of Mg-rich volcanic rocks is characterized by high SiO2, MgO and low Ti contents. Compared with the island arc tholeiite and MORB, these rocks are depleted in HFSE and are therefore similar to boninite. The dacites show V-shaped distribution REE patterns whereas the basalts display flat or 关 键 词：Mg-rich VOLCANIC rock MIDDLE DEVONIAN ALTAY Xinjiang.