APPLICATION OF U,TH ISOTOPES IN DATING YOUNG SEDIMENT

Further research on past climate change based on a reliable geochronogical framework is essential for predicting the future trend of climate change. High-sensitivity and high-precision measurement of age is one of the subjects urgent to solve. U-Th dating technique fills the gap between the 14C dating, which is only applicable to dating the sediments younger than 50 ka, and the 39Ar/40Ar method or fission-track thermorchronology, which is usually applicable to the dating of volcanic deposits older than 500 ka. Up to date, the U-Th dating technique is the first choice for the sediments in age of 50 ka to 500 ka. This paper mainly introduces the current status of the U-Th dating technique using thermal ionization mass spectrometry(TIMS)、single-collector inductively coupled plasma mass spectrometry(SC ICP-MS)and multi-collector inductively coupled plasma mass spectrometry(MC ICP-MS)respectively for sediments. Comparison of U-Th dating techniques with the methods of α-spectrometry,TIMS,SC ICP-MS and MC ICP-MS is also provided for time range,measurement precision and sample requirement.