摘要
野外和室内研究结果表明,四道河地区面理化含榴花岗岩由古生代沉积岩变质而成。在元素地球化学特征上,具有与岩浆成因的碱性花岗岩一致的特点:高硅(SiO2=75.24%～77.23%)、富碱(Na2O+K2O=6.87%～8.84%)、低铝(Al2O3=11.00%～12.78%);富Rb、Ba、Th、U等大离子亲石元素和Pb,贫Nb、Ta、Zr、Hf等高场强元素;稀土元素含量较高(∑REE=101.08～180.1μg/g),轻稀土元素相对富集(LREE/HREE=3.1～6.8),铕有中等负异常(δEu=0.30～0.68);锆石成因类型及定年结果表明,老核(继承锆石)是异地多时代(元古代-古生代),其寄主岩的原岩是沉积岩,时代不会早于古生代。
Field and laboratory studies show that the foliated garnet-bearing granites from the Sidaohe region were derived from the Paleozoic sedimentary rocks through metamorphism. Geochemical characteristics of the garnetbearing granites are similar to those of the typical alkali granites, i. e. , rich in silicon （ SiO2 = 75. 24% - 77.23%）, alkali （Na2O＋K2O=6.87% -8.84%） and poor inaluminium （Al2O3 = 11.00% -12.78%）. The rocks are rich in lithophile trace elements （Rb, Ba, Th, U） and poor in HFS elements （Nb, Ta, Zr, Hf）. The rocks are relatively rich in LREE （ ∑ REE = 101.08 -180.1 μg/g, LREE/HREE = 3.1 - 6.8） showing moderate negative Eu anomalies. Genetic types and ages of the zircons from garnet-bearing granites demonstrate that they are inherited zircons in sedimentary rocks formed no earlier than Paleozoic.
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2012年第2期293-300,共8页
Geotectonica et Metallogenia
基金
国家重点发展研究计划(973)(编号:2009CB219401)
国家自然科学基金(批准号:40534019)
中国大洋协会项目(DYXM-115-02-3-06)联合资助
