摘要
广东省连州地区文珍洞二长花岗岩体位于大东山岩体北缘,有关大东山岩体形成年代仍存在不同认识。本文通过LA-ICP-MS锆石U-Pb测年获得文珍洞二长花岗岩的成岩年龄为165.4Ma±1.9Ma,表明大东山岩体存在中侏罗世晚期岩浆活动。文珍洞二长花岗岩Al_2O_3含量为11.48%~12.68%,(Na_2O+K_2O+CaO)含量为7.40%~8.96%,Al_2O_3>(Na_2O+K_2O+CaO),SiO_2含量为73.96%~77.62%,里特曼指数(σ)为1.30~2.29,显示岩石化学类型属于硅过饱和、铝过饱和、钙碱性花岗岩类。研究表明,文珍洞二长花岗岩为形成于板内构造环境中的改造型(S型)花岗岩。
The Wenzhendong monzogranite of Lianzhou, Guangdong Province are located in the northern margin of Dadongshan rock mass, and there is still a different understanding about the formation age of Dadongshan rock mass. In this paper, the emplacement age ofWenzhendong monzogranite is 165.4 ± 1.9Ma by LA-ICP-MS zircon U- Pb dating, which indicates that the Late Jurassic advanced magmatic activity exists in the Dadongshan rock mass. Al2O3 content is 11.48 - 12.68% ,（Na2O＋K2O＋CaO） content is 7.40-8.96%, Al2O3〉 （Na2O＋K2O＋CaO）, SiO2 con- tent is 73.96 - 77.62%, the Litman index（It）is 1.30 to 2.29, indicating that the petrochemical type is silicon supersaturated, aluminum supersaturated, calc-alkaline granite. The study shows that the Wenzhendong monzogranite is a modi- fied type （S type） granite formed in the tectonic environment.
出处
《西部资源》
2017年第4期37-42,共6页
Western Resources
基金
中国地质调查"广东1:5万丰阳公社
大路边
东陂
连县幅区域地质矿产调查(编码12120114072101)"项目资助
