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中国东南沿海中生代火山岩叠置在几个不同的基底构造单元之上,不同单元内的火山岩在锶、钕同位素组成上存在着很大的差异。其中隶属于下扬子亚板块的浙西—赣东北区火山岩的~(87)Sr/~(86)Sr初始值普遍较低,而~(143)Nd/~(144)Nd初始值则较高。华夏亚板块内的火山岩,以武夷山隆起为核心向沿海方向~(143)Nd/~(144)Nd初始值不断增高,而~(87)Sr/~(86)Sr初始值则呈下降趋势。火山岩中的同位素特征及其时空变化规律在很大程度上是其基底变质杂岩中同位素性质的再现。区内中生代酸性岩浆的形成是业已存在的地壳物质再循环的结果。
The Mesozoic volcanic rocks in the southeastern China coastal area are superimposed on several different basement structural units, and the volcanic rocks in different units have very different strontium and neodymium isotopic compositions. The initial values of ~ (87) Sr / ~ (86) Sr and the ~ (143) Nd / ~ (144) Nd initial values of volcanic rocks in the western Zhejiang-northeastern Jiangxi subordinated to the Lower Yangtze subplate are generally lower . The volcanic rocks in the Huaxia subplate increase to ~ (143) Nd / ~ (144) Nd in the coastal direction and the initial values of ~ (87) Sr / ~ (86) Sr decrease with the core of the Wuyi uplift. Isotopic characteristics of volcanic rocks and their temporal and spatial variation are largely the representation of isotopic traits in their metamorphic basement. The formation of Mesozoic acidic magma in the area is the result of the recycling of existing crustal materials.