摘要
内蒙古扎鲁特旗北部黑云母二长花岗岩岩体位于兴蒙造山带东段,形成于晚三叠世.黑云母二长花岗岩岩石地球化学表现为富SiO2、Al2O3和碱质,Na2O/K2O比值小于1,A/CNK比值介于1.021~1.084之间,轻重稀土元素分馏明显,轻稀土元素富集,具明显负铕异常.微量元素中亏损Ba、Sr、Ti、P,稀土元素中亏损Eu、Yb,具有A型花岗岩的地球化学特征.结合区域地质资料和前人相关研究,推测黑云母二长花岗岩可能形成于板块内部造山后期地壳伸展减薄的环境.
The biotite monzogranite intrusive body in northern Jarud, Inner Mongolia, located in the eastern section of Daxinganling Mountains, was formed in Late Triassic Period. The rock is geochemically characterized by rich SiO2, Al2O3 and alkalis, with Na2O/K2O less than 1, MCNK between 1.021 and 1.084. The LREE and HREE are notably fractionated, with enriched LREE. The Eu negative anomaly is obvious. The trace elements show depletion of Ba, Sr, Ti, P, Eu and Yb, with the geochemical characteristics of A-type granite. Combined with regional geological data and previous research, it is supposed that the biotite monzogranite was formed in crustal stretch thinning setting of late orogenic epoch within the plate.
出处
《地质与资源》
CAS
2016年第1期11-16,共6页
Geology and Resources
基金
中国地质调查局"东北地区晚古生代地层划分对比及油气资源前景研究"(编号1212011121086)
"松辽外围中新生代盆地群油气地质综合调查"(编号1212010783001)
"松辽盆地外围深部地质调查"(编号1212011220)
关键词
A型花岗岩
地球化学特征
晚三叠纪
内蒙古
A-type granite
geochemical characteristics
Later Triassic
Inner Mongolia
