全新世臺灣南部珊瑚骨骼及軟體動物殼體穩定碳氧同位素記錄之研究（II）

We have analyzed 220 stable isotope records of coral Porites skeleton (6425-6320 yr BP), 221 archaeological Crassostrea gigas shells, and 67 stable hydrogen and oxygen isotope records of aquiculture water samples to reconstruct the Holocene paleoenviroment of southern Taiwan. Oxygen isotope values of coral skeleton are between -6.4? and -3.8?. Seasonal fluctuation are observed in oxygen isotope records. Annual temperature are estimated between 18.5°C and 31.8°C using estimated middle Holocene water oxygen isotope value. A total of 221 isotopic analyses were performed on archaeological oyster shells. In ascending order, mean oxygen isotope values of Crassostrea gigas oyster shells are -5.5±1.3? (N=71), -3.8±1.8? (N=75), and -3.5±1.4? (N=75) for Niaosong (1800-500 yr B.P.), Siraya (500-300 yr B.P.), and Han Chinese (300 yr B.P. - present) cultural components, respectively. Lower mean oxygen isotope values in Niaosong and more and less Siraya components may indicate warmer/wet environment between 1800 ~500 B.P. in southwestern Taiwan. However, there is no significant difference in mean oxygen isotope values between Han Chinese component and present (-3.1 ± 1.2?) may indicate the paleoenvironment was getting to the present condition gradually. Salinity of aquiculture water samples are between 6 psu to 36 psu during October, 2018 and September, 2019. Oxygen isotope values of water collected are between -9.8? and 0.8? and is positively correlated with salinity. Seasonal salinity and oxygen isotope variations are observed.