Abstract Dating of the Tibetan ice cores is often challenging with great uncertainties. The significant age difference between the Guliya ice core (∼760 ka thousand years) and other Tibetan ice cores (Holocene origin) necessitates new approaches to resolve the inconsistency. Here, we present the atmospheric O2 δ18O (δ18Oatm) profile of the 216.6 m Chongce ice core. Our data suggest that post depositional alterations significantly changed δ18Oatm. We reject samples with melt layers, and reconstruct the δ18Oatm values with two extreme correction approaches: a minimum isotopic correction based on gas loss fractionation, and a maximum isotopic correction based on respiration fractionation. We consequently estimate the age range of the Chongce ice core to be 2.763–7.192 ka at the depth of 215.14 m, and ∼3–9.799 ka at the depth of 215.61 m. Our work provides an independent line of evidence for the Holocene origin of the Chongce ice core.
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