南极普里兹湾表层沉积物GDGTs含量分布与TEX86指标应用研究

摘要

The contents and distribution of glycerol dialkyl glycerol tetraethers (GDGTs) were analyzed for ten surface sediments from Prydz Bay of Antarctic.The results show that the contents of GDGTs are 27.69～ 900.78 ng/g with the isoprenoid GDGTs accounts for 94％ ～ 99％,much more higher than branched GDGTs.Isoprenoid and branched GDGTs have same distribution tendency that the highest content area appears in southeast while the lowest area appears in northwest direction.Isoprenoid GDGTs and branched GDGTs both have obvious positive correlation with TOC.Analysis shows that isoprenoid GDGTs comes from marine Archaea,while branched GDGTs derives from bacteria in sediments.Compared with the WOA database,the TEX86 and TEX86L derived temperatures are consistent with the sea surface temperatures in January in the study area.This study means TEX86 and TEXs86L indexes could be applied to reconstruct the paleotemperature in Prydz Bay.%利用中国南极考察获取的沉积物样品,对普里兹湾10个表层沉积物中GDGTs的含量与分布进行分析.结果表明:普里兹湾内GDGTs含量为27.69～900.78 ng/g,其中类异戊二烯GDGTs占比94％～99％,远高于支链GDGTs.类异戊二烯GDGTs与支链GDGTs都呈现东南高、西北低的分布趋势,且与沉积物中有机碳含量显著正相关(R＞0.95).沉积物中类异戊二烯GDGTs来源于水生古菌,而支链GDGTs主要来源于沉积物中的细菌.根据GDGTs不同异构体含量计算得到的指标TEX86和TEX86都与普里兹湾1月表层海水温度呈现良好的相关性.这表明TEX86和TEX86L指标在普里兹湾海域具有适用性,可以作为重建古海温的替代指标.