U-series dating of soda straw stalactites from excavated deposits: method development and application to Blanche Cave, Naracoorte, South Australia

作者：St Pierre Emma^*; Zhao Jian xin; Feng Yue xing; Reed Elizabeth

来源：Journal of Archaeological Science, 2012, 39(4): 922-930.

DOI：10.1016/j.jas.2011.10.027

• Blanche Cave
• Naracoorte South Australia
• Limestone cave and rockshelter sites
• Quatemary chronology
• Speleothems
• Soda straw stalactites
• U/Th dating

This study aimed to further test the method, reported by St Pierre et al. (2009), to develop robust chronologies of deposits in limestone caves through U/Th (Uranium/Thorium or U-Series) dating of soda straw stalactites. The chronology of fossil bearing deposits at Blanche Cave was further constrained with thermal ionisation mass spectrometry (TIMS) U/Th dating of 17 additional soda straw stalactite samples, and results were compared to recalibrated C-14 ages of charcoal. The results support the assertion that soda straw stalactites can provide ages close to the time of sediment deposition and may be used as reliable chronological markers, particularly for periods reaching or beyond the radiocarbon dating limit. The application of an enhanced cleaning technique facilitated the reduction of detrital Th in samples, significantly increasing age accuracy and precision. Additionally U/Th age accuracy and precision was increased through the application of site-specific measured U/Th ratios to correct for the detrital Th-230 component in samples.

• 出版日期2012-4