We carried out an integrated study of zircon U–Pb geochronology, Hf isotopes and geochemistry on the paragneisses and amphibolites from the Chencai area, South China. The detrital zircon ages of four paragneisses range from 2974 to 501 Ma with the main peak at ca. 820 Ma. The detrital materials with Neoproterozoic age may derive from the Jiangnan Orogen and those of Palaeo–Mesoproterozoic age may come from the Wuyi terrane. The youngest age indicates that the protoliths of the paragneisses were formed after ca. 501 Ma. The ε_Hf(t) values (−20.6 to +20.9) of the detrital zircons suggest that the detrital materials of the protoliths are composed of old crustal and juvenile materials. The geochemical characteristics suggest that the protoliths of the paragneisses are greywackes, which formed in an active continental margin or continental island arc environment. The metamorphic ages of the three amphibolites are 428 ± 4, 430 ± 4, and 438 ± 3 Ma. The protoliths of the amphibolites are tholeiites, which can be divided into two groups. Group 1 is characterized by low ∑REE contents and (La/Yb)_N ratios showing left‐inclined REE patterns and Nb, Ta depletion which resembles N‐MORB. Group 2 has higher ∑REE contents and (La/Yb)_N ratios, with Eu negative anomalies showing affinity to E‐MORB. The data show that the Chencai Group is composed of oceanic crust remnants and continental crust materials, indicating it should be a subduction accretionary complex rather than a metasedimentary sequence and thus it cannot be regarded as the Precambrian basement of the Cathaysia Block.

中文翻译：

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华南晨彩群的石笋和闪石的地质年代学和地球化学数据：对成岩作用和构造意义的启示

我们对华南陈采地区的石笋和闪石进行了锆石U-Pb年代学，H同位素和地球化学的综合研究。四个石蜡的碎屑锆石年龄范围为2974至501 Ma，主峰在ca。820毫安 新元古代的碎屑物质可能来自江南造山带，而古中元古代的碎屑物质可能来自武夷地层。最年轻的年龄表明，帕拉尼切斯的原石是在约20年前形成的。501马。的ε_的Hf（吨）碎屑锆石的值（−20.6至+20.9）表明，原石的碎屑物质由旧地壳和幼年物质组成。地球化学特征表明，石阶石的原石是灰奇石，在活跃的大陆边缘或大陆岛弧环境中形成。这三种闪石的变质年龄为428±4、430±4和438±3 Ma。角闪石的原石是菱沸石，可以分为两组。第一组的特征是低REE含量和（La / Yb）_N比，显示出左倾REE模式和Nb，Ta损耗，类似于N-MORB。第2组具有较高的REE含量和（La / Yb）_NEu负异常显示与E-MORB有亲和力。数据表明，陈才群是由洋壳残余物和大陆壳物质组成的，表明它应该是一个俯冲增生复合体，而不是一个沉积沉积序列，因此它不能被视为华夏地块的前寒武纪基底。