矿床地质2025，Vol.44Issue(3)：597-616,20.DOI:10.16111/j.0258-7106.2025.03.005
微山稀土矿床碳酸盐化硅酸岩岩浆演化与稀土成矿关系探讨
Relationship between magmatic evolution of carbonatized silicate rock and rare earth mineralization in Weishan rare earth deposit
摘要
Abstract
The Weishan rare earth deposit,located in the eastern part of the North China Craton within the Luxi Block,is the third-largest alkaline rock-carbonatite-type light rare earth deposit in China.To explore the relationship be-tween the magmatic evolution of alkaline intrusive complex and rare earth mineralization in the Weishan deposit,petrographic,geochemical,and zircon U-Pb dating analyses were performed on the alkaline intrusions.The re-sults indicate that the intrusions in this region can be classified into four main rock types:Alkaline granite,quartz-albite porphyry,aegirine augite-bearing quartz syenite,and quartz-potassium feldspar porphyry.These rocks all exhibit similar geochemical characteristics and are classified as alkaline rocks.They are characterized by high wa-ter content,enrichment in CO32-,and distinct fractionation of light and heavy rare earth elements,with late-stage quartz-potassium feldspar porphyry showing significant enrichment in light rare earth elements.Zircon U-Pb ages for alkaline granite and quartz-potassium feldspar porphyry are(124.97±0.71)Ma(MSWD=1.7)and(124.73±0.93)Ma(MSWD=0.41),respectively.These ages are closely similar and are consistent with previously reported rare earth mineralization ages((119±1.4)Ma),suggesting a genetic relationship between the alkaline intrusions and rare earth mineralization.Geochemical features of the four alkaline rock types indicate that during magmatic evolution,oxygen fugacity steadily increased,leading to an enrichment of sodium components,CO32-,and other elements.This resulted in a dramatic increase in the mobility and enrichment of rare earth elements.In conclu-sion,the formation of alkaline rock-carbonatite-type rare earth deposits is closely linked to high-degree crystalli-zation differentiation,increased oxygen fugacity,and the accumulation of CO32-and sodium components-in CO2-rich alkaline magmas.These processes represent critical geological factors for the formation of such deposits and provide important petrological and geochemical indicators for exploration.关键词
碱性杂岩体/锆石U-Pb测年/氧逸度/稀土元素富集/微山稀土矿Key words
alkaline intrusive complex/zircon U-Pb dating/oxygen fugacity/rare earth enrichment/Weis-han rare earth deposit分类
地质学引用本文复制引用
胡紫龙,杨金昆,安茂国,支成龙,尚振,张瑶飞,赵家良,张海东,夏明哲..微山稀土矿床碳酸盐化硅酸岩岩浆演化与稀土成矿关系探讨[J].矿床地质,2025,44(3):597-616,20.基金项目
本文得到国家自然科学基金委员会面上项目(编号:42273071)、山东省联合重点基金(编号:U22A20571)、陕西省杰出青年科学基金(编号:2024JC-JCQN-41)和中央高校基金(编号:300102272202)联合资助 （编号:42273071）
