| 何涛,张健仁,黄璟,李倩,张德富.辽西庞杖子岩体年代学、岩石地球化学特征及其地质意义[J].矿产勘查,2026,17(1):30-40 |
| 辽西庞杖子岩体年代学、岩石地球化学特征及其地质意义 |
| Chronology, petrogeochemical characteristics and geological significance of potassium feldspar granite in Pangzhangzi pulton, western Liaoning |
| 投稿时间：2025-03-25 |
| DOI：10.20008/j.kckc.202601003 |
| 中文关键词: I型花岗岩 锆石 U-Pb年代学 地球化学 庞杖子 |
| 英文关键词: I-type granite zircon U-Pb dating petrogeochemistry Pangzhangzi |
| 基金项目:本文受江西省自然资源厅科技创新项目(ZRKJ20232526；ZRKJ20232411)和自然资源部离子型稀土资源与环境重点实验室开放基金课题(2022IRERE103；2023IRERE106)联合资助。 |
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| 中文摘要: |
| 庞杖子岩体位于华北克拉通北缘，为厘定其形成时代、构造环境与地质意义，本文对其开展岩石学、元素地球化学特征和 LA-ICP-MS锆石 U-Pb测年研究。结果表明，庞杖子岩体成岩年龄为(198.1±7.2)Ma，属早侏罗世。岩石地球化学特征显示岩体具有高硅、富铝、高钾钙碱性特征，属过铝质钙碱性钾长花岗岩；微量元素具有典型岛弧型花岗岩属性；稀土元素呈现轻稀土富集、重稀土亏损特征，反映壳幔混合作用下的岩浆分异过程。结合区域构造事件认为，该岩体形成于古太平洋板块持续俯冲引发的碰撞后伸展环境，俯冲板片脱水导致岩石圈地幔部分熔融形成幔源岩浆，高温侵入引发下地壳部分熔融，壳幔混合岩浆经强烈结晶分异形成高分异 I型花岗岩。 |
| 英文摘要: |
| Pangzhangzi pluton is located in the northern margin of North China Craton. In order to determine itsformation age, tectonic environment and geological significance, the petrology, elemental geochemical characteristicsand LA-ICP-MS zircon U-Pb dating of Pengzhangzi pluton are studied. The results show that the diagenesis age ofPangzhangzi pluton is (198.1±7.2) Ma, belonging to the Early Jurassic. The geochemical characteristics show that therock mass has the characteristics of high silicon, rich aluminum and high potassium calc alkalinity, belonging to per-aluminous calc alkalic potassium feldspar. The trace elements have typical island arc granite properties. The rareearth elements are characterized by light rare earth enrichment and heavy rare earth deficit, which reflects the mag-matic differentiation process under crust-mantle mixing. Combined with regional tectonic events, it is believed thatthe rock mass was formed in the post-collision extension environment caused by the continuous subduction of the an-cient Pacific Plate. The dehydration of the subduction plate led to partial melting of the lithosphere mantle to formmantle-derived magma, and the high-temperature intrusion led to partial melting of the lower crust. The crust andmantle mixed magma formed highly differentiated type I granite through strong crystallization differentiation. |
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