西北地质2017，Vol.50Issue(4)：23-32,10.
龙首山芨岭地区基性岩脉地球化学特征及其地质意义
Geochemical Characteristics of Basic Dikes from Jiling Area in Longshoushan and Its Geological Significance
摘要
Abstract
The mafie dikes from Jiling area in Longshoushan has selected been as the study object,and the magmatic source characteristics and evolutionary processhas been discussed in this paper.SiO2 content of mafic dikes in Jiling area is 47.09％～51.13％.They are characterized by high aluminum (A12O3 =14.56 ％ ～ 15.97 ％),rich sodium (Na2O =3.35 ％ ～ 3.69 ％) and low potassium (K2O=0.347％～1.23％).The ∑ REE (105.7×10-6 ～186.97 ×10-6) is relative low with the right type of LREE distribution patterns ((La/Yb)N =4.50～9.63).These mafic dikes have a characteristic of rich Ba,U,Pb,P and Ti and depleted Rb,Th and K,belonging to the tholeiite series.They were formed in extensional intraplateenvironment and experienced fractional crystallization of olivine,clinopyroxene and Ti-Fe oxides.The magma hadn't been contaminated by crustal materials during its ascent process.Its original magma was derived from the melt of the pyrolite which was formed by the mantle metasomatism after the partial melting.Thus,the magma of mafic dikes was derived from transitional mantle source region,with the source of spinel + garnet lherzolite mantle.关键词
芨岭/基性岩脉/地球化学特征/源区Key words
Jiling/mafic dikes/geochemical characteristics/source region分类
天文与地球科学引用本文复制引用
张良,张树明,魏正宇,胡菲菲,陈云杰..龙首山芨岭地区基性岩脉地球化学特征及其地质意义[J].西北地质,2017,50(4):23-32,10.基金项目
国家自然科学基金项目“龙首山产于花岗岩中的碱交代型铀矿床成矿机理研究”(41172079),中国地质调查局项目“北秦岭成矿带东段夜村—庾家河地区铀矿资源调查评价”(DD2016013623),中国核工业地质局项目“陕西省北秦岭成矿带铀资源评价与勘察”(201621) （41172079）
