Screening speleothem U/Th ages through crystal petrography analysis: A case study from Rige cave in the Southeast Tibetan Plateau

Speleothems are important recorders of hydroclimate changes. Although ²³⁰Th dating technique is a widely-used method to determine speleothem absolute chronology, geochemical and geophysical processes during deposition may lead to anomalous variations in U concentrations and generate reversed ages, impacting the establishment of age model. Here, we present a combined approach utilizing petrographic analyses and ²³⁰Th dating techniques to accurately determine the ages of speleothem sample RG-1 from southeastern Tibetan Plateau. We observed that all reversal ages were located within the mosaic regions. To address this, we resampled and measured the ages in layers while excluding the mosaic regions. The results aligned well with the age model within the margin of error. These findings introduce a method that incorporates petrography to enhance the accuracy of reversed ²³⁰Th dating.