Zhongba microterrane is an important geological unit in the western Yarlung Zangbo suture zone. It exposes between the Lhasa terrane and the Tethyan Himalayan Sedimentary Sequence （THS）, combined by ophiolite belt on both northern and southern sides. It has great significance of tectonic affinity analysis for the process of multi-block assembling of the Tibetan Plateau and Neo-Tethys. The Silurian-Carboniferous strata cropping out in the Mayum region, middle Zhongba microterrane, are studied by this research with detrital zircon chronology. The Silurian strata consist of foliated calcareous schist, marble with thin sandstone interlayer. The Devonian strata are mainly composed by foliated crystalline limestone and calcareous schist. The Carboniferous strata are characterized by a suite of fine clastic rocks with thin interlayered calcareous schist. Results of detrital zircons U-Pb dating show that the Silurian-Carboniferous strata have the similar age distributions in the relative U-Pb age probability diagram. All the samples yield ages clustering at ca. 530 Ma and ca. 950 Ma, which have a great similarity to the detrital zircons age distribution patterns of the western Qiangtang terrane and the Tethyan Himalayan Sedimentary Sequence. However, there is no age clustering at ca. 1 170 Ma, which is the typical feature of Lhasa terrane. Therefore, the detrital zircons geochronologic results reveal that the Zhongba microterrane located near the Indian Plate and was a part of the western Qiangtang-Great India-Tethyan Himalayan continental margin system during the Silurian to Carboniferous.
Lin Chao Zhang Jinjiang Huang Tianli Wang Xiaoxian Zhang Bo. Tectonic affinity of Zhongba microterrane：Constraint from detrital zircon geochronology of the Silurian-Carboniferous strata in the Mayum region, southern Tibet[J]. Chinese Journal of Geology, 2020, 55(2): 574-597.