摘要
通过大石桥硼矿区花岗质岩石成因的研究,提出花岗质岩石属层状混合花岗岩成因,并以此为指导,在辽宁大石桥地区找到了3个中型硼矿床。花岗质岩石与其围岩变(浅)粒岩为渐变过渡关系,并呈现一些特殊的结构构造。其岩石化学成分变化较大,Al过饱和,AKCN值较大,Ti含量高。其特殊的岩石化学组成及氧同位素δ18O值均>10‰,显示为混合花岗岩特征。花岗质岩石与其围岩变(浅)粒岩的REE组成特征一致,LREE/HREE平均值为3.86;负Eu异常,δEu平均为0.62,Eu/Sm平均值为0.163,与地壳来源的花岗岩及沉积岩的数值相近。该区花岗质岩石并非岩浆底辟作用形成的岩浆型花岗岩,而是层状混合花岗岩。
Based on the study of the genesis of granite in Dashiqiao borate district, considers that the granite in the area is a kind of stratified migmatitized granite. The direct result of this hypothesis is the discovery of three medium-sized borate deposits in Dashiqiao area. The granite, which is transitional to its host rock granulite, possesses some special structure and texture, fluctuating largely in its chemical component concentration. Granite displays an oversaturated Al, a higher AKCN and a higher Ti. Its petrochemical components and oxygen isotope δ18^（） of higher than 10% reveal features of migmatization. The granite is consistent with its host rock granulitite in REE. In granite, LR/HR is 3.86 on average, negative Eu anomaly is evident, δEu is 0.62 and Eu/Sm is 0. 163 on average, suggesting its similarity to crust granites and sedimentary rocks. Hence, the granite in the area is considered as stratified migmatized granite, rather than magmatic granite formed by diapirism.
出处
《吉林大学学报（地球科学版）》
EI
CAS
CSCD
北大核心
2005年第6期714-719,共6页
Journal of Jilin University：Earth Science Edition
基金
中国地质调查局国土资源大调查项目(199910300102)
