北冰洋沉积物中四醚脂类来源与TEX<sub>86</sub>指数初步研究

北冰洋沉积物中四醚脂类来源与TEX₈₆指数初步研究

摘要: 对北冰洋海域11个站位的沉积物进行了四醚脂类(GDGTs)生物标志化合物的浓度及分布特征分析,结合沉积物的TOC及TN含量及同位素组成对GDGTs的来源进行了探讨。对比TEX₈₆-SST与WOA数据库资料,研究区内美亚海盆73°N以南站位以及欧亚海盆ARC5-BB06站的TEX₈₆-SST与SST具有很好的符合性。楚科奇海域68~73°N站位样品和全球海洋TEX₈₆-SST模式一致,与年平均SST具有较好的符合性。白令海区及ARC5-BB06站TEX₈₆-SST与夏季平均SST符合性更好,可能与提供GDGT的古菌夏季的生产力更高,在全年生产力中所占比例大有关。

Abstract: Isoprenoid and branched glycerol dialkyl glycerol tetraethers (GDGTs),TOC, TN, δ¹³C and δ¹⁵N were analyzed for the surface sediments of the Arctic Ocean and the Bering Sea in order to understand their source and test the TEX₈₆ index. Compared with the WOA database, the TEX₈₆-and TEX₈₆^L -derived temperatures are consistent with the sea surface temperatures in the study area, except for the Station of ARC5-SR11near the 73°N. The TEX₈₆^L-SST are consistent with the annual mean SST from the samples located in the Chukchi Sea. The TEX₈₆^L-SST are consistent with the summer mean SST from the samples located in the Bering Sea, maybe resulted by the higher production of marine Archaea (Thaumarchaeota) in the summer.