STUDY OF OKINAWA TROUGH SEDIMENTATION RATES AND PALEOENVIRONMENT BASED ON URANIUM SERIES ISOTOPE

Spectrometry of ~(238)U, ~(234)U, ~(230)Th and, ~(232)Th in three Okinawa Trough cores showed that, based on the~(230)Th/~(232)Th activity ratio, the sedimentation rates were about 2.5 cm/ka, 2.8 cm/ka and 8.5 cm/ka respectivelyduring the Holocene and about 20.1 cm/ka, 12.29 cm/ka, 8.8 cm/ka and 12.6 cm/ka respectively during theWurm glacial. To examine the past global climatic and oceanographic changes, the stable oxygen isotopesδ~(18)O and CaCO_3 were measured. The Th content and Th/U ratio showed that variations of terrigenous materialinput from the continental shelf were associated with glacial and interglacial changes and sea level

Study of Okinawa Trough sedimentation rates and paleoenvironment based on uranium series isotope

Spectrometry of²³⁸U,²³⁴U,²³⁰Th and,²³²Th in three Okinawa Trough cores showed that, based on the²³⁰Th/²³²Th activity ratio, the sedimentation rates were about 2.5cm/ka, 2.8cm/ka and 8.5cm/ka respectively during the Holocene and about 20.1cm/ka, 12.29cm/ka, 8.8cm/ka and 12.6cm/ka respectively during the Würm glacial. To examine the past global climatic and oceanographic changes, the stable oxygen isotopes δ¹⁸O and CaCO₃ were measured. The Th content and Th/U ratio showed that variations of terrigenous material input from the continental shelf were associated with glacial and interglacial changes and sea level fluctuations. Contribution No. 2911 from Institute of Oceanology, Chinese Academy of Sciences. This research was supported by the National Natural Science Foundation of China.