35. STABLE CARBON AND NITROGEN ISOTOPE COMPOSITIONS OF ORGANIC MATTER FROM SITES 724 AND 725, OMAN MARGIN1
35. STABLE CARBON AND NITROGEN ISOTOPE COMPOSITIONS OF ORGANIC MATTER FROM SITES 724 AND 725, OMAN MARGIN1
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35. 来自阿曼边缘 724 和 725 站点的有机物的稳定碳和氮同位素组成1
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
T. Pedersen
中科院分区：
文献类型：
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作者：
A. Muzuka;S. Macko;T. Pedersen
报道了阿曼边缘(ODP724和725站)上新世至更新世-全新世沉积物的碳、氮稳定同位素组成和有机碳含量。724站位的有机碳含量一般大于2%。在该遗址更新世-全新世之前，由于有利的保存条件和/或较高的生产力，沉积了有机质含量较高的沉积物。在更新世，保存的有机质数量较少；这种物质通常具有更丰富的氮同位素组成。这可能表明随着更新世的开始，氧最小带和反硝化作用加强。这些沉积物的碳同位素含量与724号站位的氧同位素阶段的相关性表明，在冰川事件期间，13C有所富集。根据碳和氮的稳定同位素证据，似乎没有陆源异地物质在这一海洋环境中的主要输入。季风风对该区域生产力的时间和程度尚不明显，但需要进一步研究，以便对该环境的同位素和碳含量的小尺度特征进行合作解释。
Stable isotopic compositions of carbon and nitrogen and organic carbon content of sediments ranging from the Pliocene to the Pleistocene-Holocene in age from the Oman Margin (ODP Sites 724 and 725) are reported. In general, the organic carbon content is greater than 2% at Site 724. Prior to the Pleistocene-Holocene at this site, sediments with higher content of organic matter were deposited owing to favorable preservation conditions and/or higher productivity. In the Pleistocene, lower amounts of organic matter have been preserved; this material generally has more enriched nitrogen isotopic compositions. This may indicate intensification of the Oxygen Minimum Zone and denitrification with the onset of the Pleistocene. A correlation of carbon isotope content of these sediments with oxygen isotope stages at Site 724 indicates an enrichment in 13C during glacial events. Based on the stable isotope evidence of both carbon and nitrogen, there does not appear to be major input of terrigenous-derived allochthonous material in this marine environment. The timing and extent of monsoon winds on the productivity of this region are not evident, but require further studies for collaborative interpretation of small-scale features in the isotopic and carbon content of this environment.