扬子西缘新元古界黄水河群碎屑锆石年代学特征及其对罗迪尼亚超大陆重建的启示

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the Huangshuihe Group along the western margin of the Yangtze Block can providecritical insights into the Neoproterozoic tectonic evolution of this region. This study conducts a systematic petrographic and LA-ICP-MS detrital Zircon U-Pb geochronological analysis of metaclastic rocks from the Huangshuihe Group in thePengguan area.The results show that the youngest detrital zircon ages of two biotite quartz schist samples from the Huangtongjianzi Formation are 840±20Ma and 844±29Ma ， suggesting a maximum depositional age of approximately 840Ma for the Huangshuihe Group. The detrital zircon age spectra from the two samples consist of four main age peak intervals： approximately 2687～2350 ， 2228～1629 ， 1533～1413 ，and 1249～840Ma ， defining a primary peak at around 922Ma and two secondary peaks at approximately 2 499 and 1867Ma Comparisons with regional tectono-thermal events and detrital zircon age spectra from coeval strata indicate that the detritus of the Huangshuihe Group in the Pengguan area was primarily sourced from the northwestern margin of the Yangtze Block， with possible contributions from its southwestern and northern margins.Based on the results of this study and previous research， we propose that the meta-clastic rocks of the Huangshuihe Group in the Pengguan area were deposited in a basin associated with an active continental margin along the western Yangtze Block during the early Neoproterozoic， governed by subduction-related dynamics.These lines of evidence jointly locate the Yangtze Block at the exterior periphery of the Rodinia supercontinent in the early Neoproterozoic.

Key words：Neoproterozoic；Yangtze Block；Huangshuihe Group；detrital zircon； provenane analysis

罗迪尼亚（Rodinia）超大陆聚散是地球科学界长期关注的关键科学问题。（剩余35360字）