Improving U-Pb Dating Accuracy for High-U Stalagmites in Quaternary Records

This paper explores the accuracy of U-Pb dating of stalagmites with high uranium contents and high μ values of > 10000, focusing on Quaternary records. Isotope dilution thermal ionization mass spectrometry (ID-TIMS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb dating methods are compared, and it is found that LA-ICP-MS U-Pb dating yields a better precision, especially for samples up to 3 Ma. This research highlights the importance of correcting ²³⁴U/²³⁸U disequilibrium for accurate dating, though ²³⁰Th/²³⁸U calibration is not necessary for Quaternary samples. Common lead correction has a minimal effect on high-uranium samples regardless of whether 2-D or 3-D linear regression is applied to the U-Pb concordia data. The results of the LA-ICP-MS U-Pb method are consistent with those of the ID-TIMS U-Pb method for samples up to 2 Ma, and the error can reach 1.1-2.9%. Ultimately, this study provides a framework for improving the accuracy of U-Pb dating of high-resolution stalagmite records, which is crucial for paleoenvironment reconstruction.