塔里木盆地北缘二叠纪巴立克立克组凝灰岩年代学、地球化学及构造意义

Geochronology, geochemistry and tectonic significance of the Permian Balikelike Formation tuff in the northern margin of Tarim Basin

ES评分 0

DOI 10.20086/j.cnki.yskw.2023.0501
刊名
Acta Petrologica et Mineralogica
年,卷(期) 2023, 42(5)
作者
作者单位

1. 东华理工大学 核资源与环境国家重点实验室, 江西 南昌 330013;
2. 中国地质科学院 地质力学研究所, 北京 100081;
3. 核工业北京地质研究院, 北京 100029

摘要
塔里木盆地北缘广泛分布的二叠纪火山岩,对于理解天山造山带晚古生代构造演化具有重要研究意义。本文以哈拉峻地区巴立克立克组凝灰岩为研究对象,开展了地球化学、年代学和Lu-Hf同位素研究,结果显示凝灰岩富硅(SiO2=74.59%~76.18%)、富碱(Na2O+K2O=7.48%~7.79%)、低铝(Al2O3=13.80%~14.29%),属于钾玄质过铝质流纹岩类;具轻稀土元素富集、重稀土元素相对亏损的特征,具Eu弱正异常,相对富集Rb、Th等大离子亲石元素(LILE),亏损P、Nb、Ta、Ti等高场强元素(HFSE),Nb/Ta值平均为16.60,Sr/Y值平均为2.42,Mg#值平均为34.71;LA-ICP-MS锆石U-Pb年代学分析结果显示巴立克立克组凝灰岩的结晶年龄为280.47±2.58 Ma,εHf(t)值为-0.73~2.12,二阶段模式年龄(tDM2)为1 318~1 145 Ma。结合塔里木盆地北缘早二叠世的构造演化、岩浆活动及沉积分布等信息,指出巴立克立克组沉积于南天山洋壳向塔里木板块俯冲的板内裂谷盆地中,具非造山板内岩浆岩特征,可能为地幔柱作用背景下,岩石圈地幔底侵导致地壳物质部分熔融的产物,继承了壳源和幔源的双重源区特征。
Abstract
The Permian volcanic rocks widely distributed in the northern margin of the Tarim Basin are of great significance for understanding the late Paleozoic tectonic evolution of the Tianshan orogenic belt. The research object of this paper is the tuff of the Balikelike Formation in Halajun area, the geochemical, chronological and Lu-Hf isotope studies have been carried out, which show the tuff is rich in silicon (SiO2=74.59%~76.18%), high alkali (7.48%~7.79%), low aluminum (Al2O3=13.80%~14.29%), belonging to calc-alkaline peraluminous rhyolites; enriched in LREE, relatively depleted in HREE, with weakly positive Eu, relatively enriched in large ionic lithophile elements (LILE) such as Rb and Th, and depleted in high field strength elements (HFSE) such as P, Nb, Ta, Ti, the average Nb/Ta ratio is 16.60, the average Sr/Y ratio is 2.42, and the average Mg# value is 34.71. LA-ICP-MS zircon U-Pb geochronology shows that the crystallization age of the Balikelike Formation tuff is 280.47±2.58 Ma, the εHf(t) value is from -0.73 to 2.12, and the second-stage model age (tDM2) is 1 318~1 145 Ma. Combined with the early Permian tectonic evolution, magmatic rocks and sedimentary distribution characteristics of the northern margin of Tarim, it is pointed out that the Balikelike Formation was deposited in the intraplate rift basin where the oceanic crust of the South Tianshan subducted to Tarim Basin, with non-orogenic intraplate magma, which is the partial melting of ancient crustal materials under the action of lithospheric mantle and mantle plume, inheriting the dual-source characteristics of crustal and mantle sources.
关键词
塔里木盆地北缘;凝灰岩;年代学;地球化学;构造环境
KeyWord
northern margin of Tarim Basin; tuff; chronology; geochemistry; tectonic environment
基金项目
页码 613-628
  • 参考文献
  • 相关文献
  • 引用本文

闵壮,陈正乐*,潘家永,霍海龙,韩凤彬,张文高,吴玉. 塔里木盆地北缘二叠纪巴立克立克组凝灰岩年代学、地球化学及构造意义 [J]. 岩石矿物学杂志. 2023; 42; (5). 613 - 628.

  • 文献评论

相关学者

相关机构