Abstract:
To understand the Mesoproterozoic geotectonic evolution of the northern margin of the Yangtze Craton, the U-Pb dating of detrital zircons from the sedimentary strata of the Kuangshishan, Shicaohe, and Taizi formations within the Shennongjia Group have been conducted. The results reveal prominent detrital zircon age peaks at ~1.60 Ga, 2.00~2.10 Ga, and 2.50~2.70 Ga, with minor populations at 2.20~2.30 Ga and rare zircons older than 2.80 Ga. These age distributions suggest that the Shennongjia Group was deposited between 1.10 and 1.60 Ga.Comparative analysis of detrital zircon age spectra from Mesoproterozoic strata across the Yangtze Craton and its continental nucleus indicates distinct age distributions between the western and northern margins, implying relatively independent tectonic evolutionary processes during the Mesoproterozoic. While the Shennongjia Group and the Dagushi Group exhibit similar age spectra, their differing peak ages in the 1.40–1.60 Ga interval suggest divergent evolutionary histories during this period.Integrating these findings with prior studies, we propose that the Yangtze Craton likely comprised multiple independent microcontinents before the Mesoproterozoic, which were progressively amalgamated into the cratonic basement during Paleoproterozoic to Mesoproterozoic tectonic events.