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对浙东南山门地区早白垩世中酸性火山-侵入杂岩进行了稀土元素含量的ICP-MS分析,对比研究了其稀土元素地球化学特征。不同类型岩浆岩的稀土元素除Eu外具有基本一致的轻稀土富集的右倾配分模式,以及稳定的Sm/Nd,La/Nd和La/Sm比值,表明它们具有一致的岩浆源区,只是分异演化程度不同。Eu/Sm比值(0.02～0.09和0.15～0.21)及一致的Nb/Ta比值(13.9～16.9),介于地壳和地幔值之间,表明其为壳幔岩浆混合作用的产物。稀土元素协变关系显示成岩过程可能以部分熔融作用为主。结合微量元素研究,山门地区早白垩世同源岩浆活动可能与古太平洋板块俯冲碰撞后岩石圈伸展引起的弧后引张构造有关。
ICP-MS analysis of the REE content of the Early Cretaceous intermediate-acidic volcanic-intrusive complex in the Shanmen area, eastern Zhejiang, and the geochemical characteristics of its REE were contrastively studied. Rare-earth elements of different types of magmatic rocks have basically the same right-lateral distribution pattern of light rare-earth enrichment except Eu and the stable ratios of Sm / Nd, La / Nd and La / Sm, indicating that they have consistent magma source zones only Different degrees of evolution. The ratios of Eu / Sm (0.02-0.09 and 0.15-0.21) and consistent Nb / Ta ratios (13.9-16.9) are between the crust and mantle values, indicating that they are the product of crust-mantle magmatic mixing. The covariant relationship between rare earth elements shows that the diagenesis may be dominated by partial melting. Combined with trace element studies, the Early Cretaceous magmatic activity in the Shanmen area may be related to the post-arc extension structure caused by lithospheric extension after the subduction collision of the Paleo-Pacific plate.