| 张龙,张兴康,刘阳,刘继勇,许浩杰.鲁西圣水峪地区变角闪辉长岩年代学、地球化学特征及其构造意义[J].矿产勘查,2026,2(2):234-245 |
| 鲁西圣水峪地区变角闪辉长岩年代学、地球化学特征及其构造意义 |
| Geochronology, geochemistry characteristics and tectonic significance of meta-hornblende gabbro in Shengshuiyu area, western Shandong Province |
| 投稿时间：2025-02-24 |
| DOI：10.20008/j.kckc.202602002 |
| 中文关键词: 地球化学 新太古代 锆石 U-Pb年龄 变角闪辉长岩 圣水峪 鲁西 |
| 英文关键词: geochemistry Neoarchean zircon U-Pb age meta-hornblende gabbro Shengshuiyu western Shandong Province |
| 基金项目:本文受山东省省级地质勘查项目(鲁勘字[2022]61号)资助。 |
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| 中文摘要: |
| 鲁西新太古代经历多期华北克拉通化和地壳增生作用，在圣水峪地区广泛分布闪长岩和二长花岗岩，其形成时代为 2540～2530 Ma。在圣水峪地区新太古界结晶基底中发育的变角闪辉长岩包体，本文对其开展岩相学、锆石 U-Pb年代学和地球化学的研究，揭示其岩浆演化特征、岩浆源区信息及构造格架。研究发现变角闪辉长岩以贫 K2O、Na2O＞K2O为特征，里特曼指数 σ为 2.07～5.91，属于碱性系列；Nb/Ta值为 14.90～31.30，比值中等，岩浆源区来自岩石地幔；全岩 ∑ REE中等(39.31×10-6～199.28×10-6)，LREE/HREE为 4.74～12.10，(La/Yb)N值为 2.82～16.90，显示轻稀土元素富集，δEu为 0.78～1.19，显示微弱负 Eu异常。变角闪辉长岩锆石 U-Pb年龄为(2558±17)Ma(MSWD=3.7，n=24)，为新太古代晚期。岩石地球化学分析显示岩浆起源于亏损地幔源区，形成于岛弧环境，为洋壳板块俯冲至地幔，引发大规模岩浆侵位在地表形的基性—超基性岩体。 |
| 英文摘要: |
| The Western Shandong experienced multiple periods of North China cratonization and crustal accre-tion in Neoarchean, and monzogranite and diorite are widely distributed in shengshuiyu area. In this paper, petrogra-phy, zircon U-Pb chronology and geochemistry are studied to reveal the magmatic evolution characteristics, mag-matic source region information and tectonic framework of the metacorphogabbro inclusions developed in the Neoar-chean crystalline basement of Shengshuiyu area.The gabbros are characterized by poor K2O and NaO>K2O, and the Rittman index σ is 2.07 -5.91, which belong to alkaline series. The Nb / Ta values range from 14.90 to 31.30, indi-cating that the magmatic source is from the mantle. The total amount of REE is moderate (39.31×10-6-199.28×10-6), and the ratio of LREE/HREE is 4.74-12.10, while the (La/Yb)N value is 2.82-16.90, indicating that LREE is en-riched. The δEu is 0.78-1.19, indicating weakly negative Eu anomaly. Zircon LA-ICP-MS U-Pb age of gabbro is(2558±17) Ma (MSWD=3.7, n=24), which is formed in the Neoarchean. The results of petro-geochemical analysisshow that the magma originated from the depleted mantle region and formed in the island arc environment, and thisbasic-ultrabasic rock mass formed accompanied by the oceanic plate subducted to the mantle and large-scalemagma emplacement on the surface. |
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