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（III）

We have analyzed 783 stable isotope records of coral Porites skeleton (～82005-7900 yr BP) collected from southern Taiwan, 300 stable isotope records of archaeological Tegillarca granosa shells collected from Tainan Science and Technology Park archaeological sites, and 41 stable isotope records of modern oyster samples collected from Qigu area Taiwan to reconstruct the Holocene paleoenvironment of southwest and south Taiwan. Oxygen isotope values of coral skeleton are between -5.3? and -2.6? (average -4.2 ± 0.6?; VPDB). Roughly 100 seasonal fluctuations are observed in oxygen isotope records. Assuming seawater oxygen isotope was 0?, mean seawater temperature was 22 ± 3 °C using the oxygen isotope equation of Abe et al. (1998). Mean oxygen isotope values of 5 Tegillarca granosa shells are respectively -3.1 ± 1.5? (E67; N = 65) for Dahu cultural component (3300-1800 yr B.P.), -2.9 ± 1.5? (E36; N = 19) and -3.8 ± 1.1? (E54; N = 85) for Niaosong cultural component (1800-500 yr B.P.), and -2.6 ± 1.5? (E07; N = 88) and -3.0 ± 1.6? (E08; N = 43) for Han Chinese cultural component (300 yr B.P. - present). Seasonal fluctuation in individual Tegillarca granosa shells are observed. The harvest season for these Tegillarca granosa shells were mainly in summer. T. granosa shell mean oxygen isotope values of Dahu, Niaosong, and Han Chinese cultural components are comparable to those of Han Chinese and modern oyster shells, whereas are greater than those of coeval archaeological oyster shells. Higher oxygen isotope values may be caused by different habitats of different mollusks and need to be further studied. For these three phases of this project, oxygen isotope values of water collected are between -9.8? and 0.8? (N =1091). The water oxygen isotope values are positively correlated with salinity. Higher oxygen isotope and salinity values in winter whereas lower in summer are well correlated to the amount of precipitation in southern Taiwan. Therefore, mollusk shell oxygen isotope records can be applied in the reconstructing of paleoenvironment of southern Taiwan.