西北地质2017，Vol.50Issue(3)：12-21,10.
青海省拉陵高里河一带中三叠世花岗闪长岩地球化学特征及其意义
Petrochemical Characteristics and Geological Significance of Middle Triassic Granodiorites from Lalinggaoli River Area in Qinghai
摘要
Abstract
The intermediate-acid intrusive rocks are intensively developed in Lalinggaili river area,Qinghai,which is a rock combination of diorite,quartz diorite,tonalite,granodiorite and monzonitic granite with fine grain.Through the analysis of the granite diorite,the results show that SiO2,Al2O3,K2O,Na2O,CaO values and σ indexes range from 67.01％ to 70.92％,from 14.13％ to 15.44％,from 3.18％ to 4.03％,from 2.78％ to 3.74％,from 2.6％ to 4.15％ and from 1.6 tol.92,respectively.The geochemical characteristics suggest that these granites belong to high potassium calc-alkaline series.REE characteristics show that,the ∑ REE values are 106.48 × 10-6～ 145.87 × 10-6,LREE/HREE ratios vary from 8.967 to15.136,and the δEu value range from 0.504 to 0.83.The spider patterns are the right-incline,with low Eu positive abnormality and LREE-rich smooth curves.The trace element characteristics indicate that they are enriched in LILE (Rb,Ce,Th,LREE) and depleted in HFSE (Nb,P,Ti,Sr,Ba).The LAICP-MS zircon U-Pb age of granodiorite is (234.9±1.3) Ma,which was formed in Middle Triassic epoch.By constructing environmental analysis,it is believed that the granodiorite from Lalinggaili river area is came from the crust-mantle mixed source,which was served as the product of crustal melting during intracontinental subduction stage,with the participation of mantle materials.关键词
花岗闪长岩/地球化学特征/构造环境/中三叠世/拉陵高里河Key words
granodiorite/geochemical characteristics/tectonic environment/Middle Triassic epoch分类
天文与地球科学引用本文复制引用
赵明福,李成福,史连昌,韩建军,徐博,柴云..青海省拉陵高里河一带中三叠世花岗闪长岩地球化学特征及其意义[J].西北地质,2017,50(3):12-21,10.基金项目
中国地质调查局西安地质调查中心“青海省祁漫塔格地区1∶5万多元地质信息集成与找矿预测”(12120114000201)资助 （12120114000201）
