Geochemical Features and Ages of the Intrusive Rocks from Yantan Belt in Beishan Area of Xinjiang and Their Geological Implications
详细信息
- 责任者：Qu Cuixia (College of Earth Science and Resources ; Chang’an University ; Xi’an 710054 ; China) ; Yang Xingke
- 刊名：Geology in China
- 出版年：2013
- 卷期：40(5)
- 关键词：I型花岗岩 ; I-type granite ; 新疆 ; Xinjiang
- 页码：p.1409-1420
- 图表：9 illus., 3 tables, 27 refs.
- 分类号：0801
- issnNo：ISSN1000-3657
- isbnNo：CN11-1167/P
摘要
This paper deals with petrologic and geochemical features and zircon U-Pb isotope ages of the intrusive rocks from Yantan belt in Beishan area,which are mainly composed of quartz diorite, granodiorite, monzonitic granite, K-feldspar granite, granite and granite-porphyry, belonging to high-K calc-alkaline and calc-alkaline series; All the rocks are characterized by enrichment of LREE,depletion of HREE and strong Eu negative anomalies. The trace elements are enriched in LILE(Rb, Th), and depleted in Sr, Nb, Ta evidently. The zircon SHRIMP U-Pb ages of the quartz diorite and granite are(296±4.1) Ma and(294±3.7) Ma respectively, both of the data are consistent within test errors, suggesting that the rocks were formed at the beginning of the early Permian period. An analysis suggests that these intrusive rocks are I-type granite which are indicative of the underplating of the mantle material into the lower crust and the formation of these rocks in the post-collision tectonic environment after the closure of Beishan rift. The result shows that the Beishan rift was closed in the early Permian in the study area.