地质学报2016，Vol.90Issue(4)：739-751,13.
阿尔金奇克山东斜长角闪岩地球化学、年代学及其成因意义
Geochemistry and Geochronology of Amphibolite in the East of Qikeshan in South Altyn Tagh and Their Genetic Significance
摘要
Abstract
The geochemical analysis of the amphibolite in the east of Qikeshan indicates it belongs to tholeiitic series with high SiO2 and Al2 O3 contents of 46.99%~51.01% and 13.85% ~15.82%,MgO and FeOT contents of 7.00%~7.71% and 12.4%~13.5%.Diagrams of MgO vs.SiO2 ,Al2 O3 ,CaO and FeOT,Cr vs.Rb and Rb/Nb vs.Rb/Zr exhibit that partial melting and fractional crystallization has occurred in the magma evolution.And the slightly enrichment of light rare earth element (LREE)implies the magma has experienced a 10% to 20% of partial melting and low fractional crystallization.Zircon Lu-Hf isotopic data reveal that the protolith was from the mantle-derived magma which was slightly differentiated from the chondrite,and the liquid temperature of the magma was 1175 ~1251℃.Microanalytical dating shows the protolith has an age of 718 ±22Ma with a metamorphic age of 502 ±14Ma.The new data and previous studies indicate that the protolith was not the product of the Neoarchean Era,but formed in the expansion period after the assembly of the Neoproterozoic Rodinia supercontinent, and experienced the peak metamorphism of early Paleozoic South Altyn,revealing that the original ancient Tethys was closed in 502 ±14 Ma.关键词
地球化学/U-Pb 年龄/Lu-Hf 同位素/成因/基性岩/阿尔金Key words
geochemistry/U-Pb age/Lu-Hf isotope/genesis/amphibolite/Altyn Tagh引用本文复制引用
王立社,李智明,仇银江,张耀选,詹小弟..阿尔金奇克山东斜长角闪岩地球化学、年代学及其成因意义[J].地质学报,2016,90(4):739-751,13.基金项目
本文由国家自然科学基金（批准号41103021；41272089；41302051）、中国地质调查局项目（项目编码1212011220861）和陕西省科学技术研究发展计划项目（2014JM2-4037）资助。 （）
