The development of in situ cosmogenic 14C analysis and its application

Compared to long-lived in situ cosmogenic nuclides like 10Be and 26Al, the short half-life of 14C minimizes the influence of nuclide inheritance effects on exposure age. Its sensitivity to changes in surface processes over short time scales makes it an ideal tool for studying landscape changes over the past 25000 years. However, in situ 14C extraction is challenging due to the low 14C concentrations in terrestrial rocks and the contamination by atmospheric 14C, which has long hampered the development of in situ 14C analysis and its applications. Currently, there are only a few operational in situ 14C extraction systems worldwide, some of which have achieved low blank levels ((1~3)×104 14C atoms) and automation. The routine analysis and widespread application of in situ 14C rely on further methodological advances, including reducing the blank levels, improving analytical reproducibility, and determining more accurate production rates. Cosmogenic nuclides such as 10Be and 26Al are widely used in China for studies in Earth surface sciences. However, research related to in situ 14C remains limited. Therefore, there is an urgent need to establish and develop in situ 14C analysis techniques. Following the high-temperature method, we are constructing an in situ 14C extraction and purification system at Xi'an AMS Center. It is expected to conduct to enrich research methods for landscape evolution in China.