Geology, Geochemistry of Langao Mafic Volcanic Rocks in South Qinling Orogenic Belt and Its Tectonic Implications

• 责任者：Chen Youzhang (Key Laboratory of Orogenic Belts and Crustal Evolution ; Ministry of Education ; School of Earth and Space Sciences ; Peking University ; Beijing 100871 ; China) ; Liu Shuwen
• 刊名：Acta Scientiarum Naturalium Universitatis Pekinensis
• 出版年：2010
• 卷期：46(4)
• 关键词：火山岩 ; volcanic rocks ; 岩石地球化学 ; lithogeochemistry ; 秦岭 ; Qinling Mountains
• 页码：p.607-619
• 图表：9 illus., 1 table, 64 refs.
• 分类号：0801
• issnNo：ISSN0479-8023
• isbnNo：CN11-2442/N

 To study the petrogenesis and tectonic setting of Langao mafic volcanic rocks in South Qinling orogenic belt, basalts and volcanic breccias are sampled from Langao County for petrography, major elements,trace elements and REE analysis. The results show that they are classified to alkaline basalts, and characterized by strong differentiation between LREE and HREE, Rb, K depletion relative to Th,Hf and no Nb, Ta, Zr, Ti negative anomalies. All of the samples display highly consistent REE patterns and trace elements spider diagrams with OIB. Petrogenenis studies reveal that they were derived from a congenetic primitive magma which was the product of low-degree partial melting of the spinel-garnet lherzolites and garnet lherzolites.