Multispecies stable isotopes of benthic foraminifers reveal past changes of organic matter decomposition and deepwater oxygenation in the Arabian Sea
Multispecies stable isotopes of benthic foraminifers reveal past changes of organic matter decomposition and deepwater oxygenation in the Arabian Sea
复制标题
底栖有孔虫的多种稳定同位素揭示了阿拉伯海有机物分解和深水氧合的过去变化
DOI：
10.1029/2006pa001284
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
A. Mackensen
中科院分区：
文献类型：
--
作者：
G. Schmiedl;A. Mackensen
[1]确定了阿拉伯海西部1800 m水深沉积物岩心中1种表层动物和3种底栖动物有孔虫物种的稳定同位素组成，以评价过去190，000年期间的深水氧合、有机质矿化和早期成岩过程。δ 18 O记录揭示了物种特有的代谢效应、对碳酸盐离子浓度变化的敏感性和超斜长石方解石溶解。有孔虫δ 13 C记录揭示了孔隙水溶解无机碳的稳定碳同位素梯度（δ 13 CDIC）和底栖动物物种微生境深度的变化。底层水和孔隙沃茨之间的最大δ 13 CDIC偏移范围在平均值0.8和1.2‰之间，对应于深水氧浓度的估计值约为1和2.7 mL L−1。深水氧合改善的时间间隔与高底栖有孔虫多样性相吻合，表明间冰期期间氧合良好的深水物质的混合。在间冰期最大期间，表层动物和浅部动物之间的δ 13 C差异表明在有机质通量最大时有机质的再矿化率最高。
[1] The stable isotope composition of one epifaunal and three infaunal benthic foraminiferal species of a sediment core from 1800 m water depth of the western Arabian Sea was determined to evaluate deepwater oxygenation, organic matter remineralization, and early diagenetic processes during the past 190,000 years. The δ18O records reveal species-specific metabolic effects, susceptibility to changes in carbonate ion concentration, and supralysoclinal calcite dissolution. The foraminiferal δ13C records reveal changes in the stable carbon isotope gradients of pore water dissolved inorganic carbon (δ13CDIC) and in the microhabitat depth of infaunal species. Maximum δ13CDIC offsets between bottom and pore waters ranged between mean values of 0.8 and 1.2‰ corresponding to estimates of deepwater oxygen concentration between approximately 1 and 2.7 mL L−1. Intervals of improved deepwater oxygenation coincided with high benthic foraminiferal diversity and indicate the admixture of well-oxygenated deepwater masses during interglacials. During interglacial maxima the δ13C difference between epifauna and shallow infauna indicates highest organic matter remineralization rates at times of maximum organic matter fluxes.