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地球化学研究表明,大蒲柴河岩体具有典型的埃达克岩特征,来自加厚下地壳的部分熔融作用。本文采用激光等离子质谱对该岩体进行了U-Pb同位素定年,结果表明该岩体为晚侏罗世(165Ma)岩浆活动的产物。锆石的LA-MC-ICPMS Hf同位素研究结果显示,ε_(Hf)(165Ma)范围为-5.02～5.43,二阶段Hf模式年龄(t_(DM2)范围为965～1622Ma,暗示原始母岩浆为两种不同源区岩浆的混合。另外,Hf同位素研究表明,研究区在中-新元古代时(965～1304Ma)曾经历了一次重要的地壳增生事件。
Geochemical studies show that the Dahuchaihehe pluton has the typical adakite characteristics derived from the partial melting of the lower thickening crust. In this paper, U-Pb isotope dating of the rock mass is carried out by laser plasma mass spectrometry. The results show that this rock mass is the product of magmatic activity of Late Jurassic (165 Ma). The results of LA-MC-ICPMS Hf isotopic studies of zircon show that the ε_ (Hf) (165Ma) ranged from -5.02 to 5.43 and the second-stage Hf mode age ranged from 965 to 1622Ma, suggesting that the original parent magma was two In addition, Hf isotope studies have shown that the study area experienced an important crustal accretion event during the Meso-Neoproterozoic (965-1304 Ma).