A combined U-Pb geochronology, whole-rock geochemistry, and Sr-Nd isotopic study give new insights into the nature of the protolith, tectonic setting, and petrogenetic history of Cadomian orthogneisses from the Tutak metamorphic complex (TMC), Sanandaj-Sirjan Zone, Iran. U–Pb zircon dates of 535 ± 4 Ma suggest an Early Cambrian crystallization age for the orthogneiss protoliths. Geochemical data indicate that the orthogneisses have I-type, high-K calc-alkaline, and peraluminous signatures. Depletion in Nb, Ta, Ti, Sr, and enrichment in Nd, Th, K, U relative to the primitive mantle, suggest derivation in a subduction zone environment in an active continental margin. Initial ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd ratios vary from 0.7045 to 0.7092 and from 0.5116 to 0.5117, respectively. Moreover, εNd_(t) values range from − 2.95 to − 5.29, and two-stage model ages vary from 1.4 to 1.6 Ga. Taken together, these data suggest derivation of TMC orthogneisses from a metasomatic lithospheric mantle with a contribution of a crustal component generated via partial melting of a metabasite (i.e., amphibolite).

结合 U-Pb 年代学、全岩地球化学和 Sr-Nd 同位素研究，对来自 Sanandaj-Sirjan 带 Tutak 变质复合体 (TMC) 的 Cadomian 正片麻岩的原岩性质、构造环境和成岩历史提供了新的见解，伊朗。U-Pb 锆石年龄为 535 ± 4 Ma，表明正方麻岩原岩的结晶年龄为早寒武世。地球化学数据表明正方麻岩具有 I 型、高钾钙碱性和过铝质特征。相对于原始地幔，Nb、Ta、Ti、Sr 的贫化和 Nd、Th、K、U 的富集表明是在活动大陆边缘的俯冲带环境中产生的。初始⁸⁷ Sr/ ⁸⁶ Sr 和¹⁴³ Nd/ ¹⁴⁴Nd 比率分别从 0.7045 到 0.7092 和从 0.5116 到 0.5117 不等。此外，εNd _(t)值范围从 - 2.95 到 - 5.29，两阶段模型年龄从 1.4 到 1.6 Ga。 综上所述，这些数据表明 TMC 正片麻岩来自交代岩石圈地幔，并具有地壳成分的贡献通过偏铝石（即角闪石）的部分熔化生成。