摘要
新疆富蕴县西部上石炭统喀喇额尔齐斯组的变质火山岩,是一套多旋回双峰式古裂谷型火山岩.基性成员为玄武岩。酸性成员为流纹岩.基性岩套由拉斑玄武岩-碱性玄武岩组成.微量元素分配模式证明了地幔成分不均一性;玄武岩浆来自石榴二辉橄榄岩44％的分批熔融;证明古裂谷是在岛弧基础上演化形成。从而说明额尔齐斯断裂带经历了俯冲-碰撞-裂谷三个演化阶段.晚期的碱性玄武岩喷发,标志裂谷作用的消亡.
Metamorphic volcanic rocks of Upper Carboniferous Karaertix Formation in the west of Fuyun County of Xinjiang is a suite of old-rift type volcanic rocks of the multicycle and bimodal type. The basic and acidic members are basalt and rhyolite respectively. Basic suite consists of tholeiite and alkali-basalt. Distribution model of frace elements testifles that the mantle composition is nonuniform, and the basaltic magma came from batch melting of 44% of garnet-lherzolite, as well as that old-rift evolved from the island are setting. Thus, Ertix rift zone underwent three cvolutional stages of downgoing-collision-rift. Eruption of the later alkali-basalt indicates thc subduction of rifting.
出处
《矿物岩石》
CAS
CSCD
1990年第3期15-23,共9页
Mineralogy and Petrology
关键词
火山岩
裂谷
新疆
额尔齐斯
玄武岩
Xinjiang
Ertix
rifting
bimodal volcanic rocks
basalt
