| 赵奎,张德富,陈士海,吕鑫,吴之正.碱厂岩体碱长花岗岩年代学、岩石地球化学特征及其地质意义[J].矿产勘查,2025,16(7):1563-1575 |
| 碱厂岩体碱长花岗岩年代学、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 the Jianchang pulton |
| 投稿时间：2025-05-04 |
| DOI：10.20008/j.kckc.202507001 |
| 中文关键词: 钾长花岗岩 锆石 U-Pb年代学 全岩地球化学 碱厂岩体 |
| 英文关键词: potassium feldspar granite zircon U-Pb geochronology whole-rock geochemistry Jianchang pluton |
| 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: |
| 辽西地区位于华北克拉通东北缘，受太平洋板块俯冲影响，中生代发生强烈构造-岩浆活动，形成大量花岗岩侵入体及钼多金属矿床。本文以碱厂碱长花岗岩为研究对象，通过岩相学、地球化学及锆石 U-Pb年代学(155.8±0.7 Ma)分析，揭示其形成于晚侏罗世，与区域辉钼矿 Re-Os年龄(185～150 Ma)吻合。岩石具高硅(SiO2=71.27%～77.10%)、富碱(Na2O+K2O=7.82%～8.87%)、过铝质特征，属高钾钙碱性 I型花岗岩，轻稀土富集(LREE/HREE=8.42～19.04)及铕负异常(δEu=0.36～0.77)指示强烈结晶分异。地球化学判别显示岩浆源于壳幔混熔，并受板片流体交代。区域构造分析表明，钼矿化与晚侏罗世陆内造山背景下深部流体活动及北东向断裂控矿密切相关，为辽西钼矿勘探提供理论依据。 |
| 英文摘要: |
| The western Liaoning region is situated at the northeastern margin of the North China Craton. Influ-enced by the subduction of the Pacific Plate, intense Mesozoic tectono-magmatic activities occurred, leading to theformation of numerous granitic intrusions and Mo-polymetallic deposits. This study focuses on the potassium feld-spar granite from the Jianchang Pluton. Through petrographic, geochemical, and zircon U-Pb geochronologicalanalyses (155.8±0.7 Ma), it is revealed that the granite was emplaced during the Late Jurassic, consistent with re-gional molybdenite Re-Os ages (185-150 Ma). The rocks exhibit high silica (SiO2=71.27%-77.10%), alkali-rich (Na2O+K2O=7.82%-8.87%), and peraluminous characteristics, belonging to high-K calc-alkaline I-type granites.Light rare earth element (LREE) enrichment (LREE/HREE=8.42-19.04) and pronounced negative Eu anomalies(δEu=0.36-0.77) indicate significant fractional crystallization. Geochemical discrimination suggests that the magmaoriginated from crust-mantle mixing and was metasomatized by slab-derived fluids. Regional tectonic analysis dem-onstrates that Mo mineralization is closely associated with deep-seated fluid activity and NE-trending fault-controlled mineralization under a Late Jurassic intracontinental orogenic setting, providing theoretical insights forMo exploration in western Liaoning. |
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