揚(yáng)子西緣新元古界黃水河群碎屑鋯石年代學(xué)特征及其對(duì)羅迪尼亞超大陸重建的啟示

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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

羅迪尼亞（Rodinia）超大陸聚散是地球科學(xué)界長(zhǎng)期關(guān)注的關(guān)鍵科學(xué)問題。（剩余35360字）