对采自南海西沙的3种不同种的现代砗磲(库氏砗磲、鳞砗磲、砗蚝)进行了高分辨率Sr/Ca比值分析.结果表明:库氏砗磲和鳞砗磲的St/Ca比值呈现出年周期变化并与实测的海表面温度(SST)形成较好的对应;而砗蚝的Sr/Ca比值年周期信号较弱且与温度的对应存在较大的不确定性.通过全年逐月或逐周对应和极端对应,我们共获得了两种砗磲的4个有效的Sr/Ca-SST方程,并能较好地作为St/Ca温度计进行温度恢复.对比不同种类的砗磲,其Sr/Ca分布有所不同,相应的Sr/Ca—SST方程也有一定的区别.这项研究为选择性地应用砗磲研究全新世气候变化提供了依据.
Three modern Tridacna specimens of different species were collected from Xisha Islands of South China Sea and the high-resolution Sr/Ca ratios of their inner shells were analyzed. Two Sr/Ca profiles of Tridacna (Tridacna gigas, Tridacna squarnosa) display regular seasonal variations and close correlation with the instrumental sea surface temperature (SST) of the studied area. Four statistically significant models were proposed based on the linear regression of the Sr/Ca ratios (monthly or weekly values and extreme values) and the SST. These models could be used to reconstruct the SST of Holocene from the Sr/Ca ratio of Tridacna's inner shells.