Petrogenesis of Xiaohaizi Syenite Complex from Bachu Area, Tarim
详细信息
- 责任者：Wei Xun (State Key Laboratory of Isotope Geochemistry ; Guangzhou Institute of Geochemistry ; Chinese Academy of Sciences ; Guangzhou 510640 ; China) ; Xu Yigang
- 刊名：Acta Petrologica Sinica
- 出版年：2011
- 卷期：27(10)
- 关键词：正长岩 ; syenites ; 塔里木盆地 ; Tarim Basin
- 页码：p.2984-3004
- 图表：6 illus., 7 tables, 106 refs.
- 分类号：0801
- 出版序号：219
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
Xiaohaizi syenite complex located within Tarim Basin is an important part of Permian Tarim Large Igneous Provinces (LIPs). SIMS zircon U-Pb analysis yields Early Permian age of (279.7±2.0) Ma, and coeval with diabase and quartz syenite porphyry dikes in the same area. Based on mineralogical composition, it can be categorized into fayalite syenite and amphibole syenite. Xiaohaizi syenites are ferroan, alkaline series and enriched in LREEs relative to HREEs with pronounced positive Eu anomalies, but no negative Nb and Ta anomalies. Geochemical and Sr-Nd isotopic compositions [(87Sr/86Sr)i=0.7033~0.7038, εNd(t)=+3.1~+3.8] indicate that they were derived from a depleted mantle source without crustal assimilation.