Detrital zircon U-Pb-Hf-O isotopes and trace elements of the Mesoproterozoic sediments on the northern margin of the North China Craton and its implications

The supracrustal rock successions along the northern margin of the North China Craton (NCC) records key information of Mesoproterozoic rifting linked to the NCC’s separation from the Columbia (Nuna) supercontinent. The Mesoproterozoic tectonic affinity and evolution of the northern margin of the NCC are controversial, hindering our understanding on its rifting, especially its time. Thus, we carry out a comprehensive study of zircon U-Pb-Hf-O isotopes and trace element on Meso- and Neo-proterozoic successions of the Mesoproterozoic Langshan-Zha’ertai-Bayan Obo-Huade (LZBH) rift from Siziwangqi area, Inner Mongolia. Our study shows that Meso- and Neo-proterozoic successions there can be roughly separated into two parts by a regional uncomformity. Sediments deposited at approximately ∼1.81–1.35 Ga are predominantly composed of late Archean to early Paleoproterozoic (mainly at ca. 3.00–1.85 Ga) zircons, having complex ε_Hf(t) and δ18O values characterized by variable ε_Hf(t) at ca. 2.5 Ga (−14.6 to +6.6) and 1.95–1.85 Ga (−10.4 to +3.0) intervals, and occurrences of high δ18O (>7‰) values. Whereas those overlying sediments deposited at ca. 1.19–0.90 Ga are dominated by late Paleo- to Mesoproterozoic (ca. 1.80–1.20 Ga) zircons, with variable ε_Hf(t) (−16.6 to +10.8) and δ18O (10.5 to 3.6‰) values showing a temporal trend toward greater mantle input with a notable shift toward mantle-dominated signatures after approximately 1.6 Ga. Similar provenance shift occurred along the entire northern margin of the NCC, as reported by many previous works. Integrating ca. 1.35–1.30 Ga magmatic records (e.g., mafic dyke swarms, A-type granites) there, we interpret this shift to date the NCC-Columbia final breakup at ca. 1.35–1.30 Ga. According to similar Archean-Paleoproterozoic detrital zircons from Mesoproterozoic (>1.35 Ga) sediments, we further proposed that the northern NCC has a tectonic affinity with Southern Siberia, and North India. Furthermore, the northern NCC has a close paleo-position to the Baltic Craton and microcontinents in the Central Asia Orogenic Belt within the Columbia supercontinent, due to similar Mesoproterozoic (ca. 1.60-1.20 Ga) detrital zircons and roughly coeval magmatism.