Detrital zircon U–Pb ages from the Middle to Late Permian strata of the Yiyang area, southern North China Craton: Implications for the Mianlue oceanic crust subduction. (6th November 2018) - Wang, Yanpeng
Abstract : Basin formation and sedimentary development in the southern North China Craton (NCC) are closely related to the tectonic evolution of the Qinling Orogenic Belt (QOB). With the aim of revealing the coupling evolution between the QOB and southern NCC during the Late Palaeozoic, an investigation based on provenance analysis was performed in this study. We present new detrital zircon U–Pb data from the Middle–Late Permian sediments in the Yiyang area, southern NCC. The results show that detrital zircons, from the Middle Permian Shihezi Formation, have three major peaks at 2, 447, 1, 905, and 296 Ma. In contrast, the lower and upper parts of the Late Permian Sunjiagou Formation yield major peaks at ~1.85 Ga and ~260 Ma, with weak peaks at ~2.5 Ga, ~450 Ma, and ~315 Ma, and the middle part of the Sunjiagou Formation displays a major peak at 429 Ma. Combined with published palaeocurrent data and lithofacies palaeogeography, the sediments of the Middle Permian Shihezi Formation were sourced from the Inner Mongolia Palaeo‐Uplift along the northern margin of the NCC, whereas the Upper Permian Sunjiagou Formation originated mainly from the southern margin of the NCC including the North Qinling Belt. This provenance shift indicates that the North Qinling Belt and southern margin of the NCC initiated the uplift and exhumation during the Late Permian. On the basis of the evolutionary history of the QOB, we attribute the uplift geodynamics to the Mianlue oceanic crust subduction. This study provides important sedimentological constraints for the tectonic conversion during the Late Palaeozoic along the southern margin of the NCC, which also restricts the start‐up time of the Mianlue oceanic crust subduction from the perspective of the basin–mountain system.