High primary productivity during the Ediacaran Period revealed by the covariation of paired C-isotopic records from South China
High primary productivity during the Ediacaran Period revealed by the covariation of paired C-isotopic records from South China
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华南成对C同位素记录的协变揭示了埃迪卡拉纪的高初级生产力
DOI：
10.1016/j.precamres.2019.105411
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发表时间：
2020-10
影响因子：
3.8
通讯作者：
Yanan Shen
中科院分区：
文献类型：
--
作者：
Yunpei Gao;Xiaolin Zhang;Yilun Xu;Chenxi Fang;Yizhe Gong;Yanan Shen
在新元古代晚期，碳酸盐碳同位素（δ 13 Ccarb）显著偏移，有机碳同位素（δ 13 Corg）值不变。前寒武纪的δ 13 Ccarb和δ 13 Corg之间的这种解耦关系与大多数古生代记录不同，这些记录基本上是由水相光合作用留下的，它被初步解释为外来有机质输入或成岩作用的结果。在这项研究中，我们提出了高分辨率的δ 13 Corg记录结合先前公布的δ 13 Ccarb数据从连续钻孔岩心从中国南方扬子地台。研究层段横跨寒武系晏家河组底部、寒武系南沱组、埃迪卡拉系陡山沱组和灯影组。该岩心的δ 13 Ccarb剖面可以与同期层序可靠地对比，并揭示了与磷块岩矿床相关的多次负δ 13 Ccarb偏移。有趣的是，δ 13 Corg剖面与δ 13 Ccarb剖面呈现共变趋势，δ 13 Ccarb与δ 13 Corg之间的耦合关系在前寒武纪的地质记录中是罕见的。岩芯的δ 13 Corg值在−22.13‰ ~ −34.12‰之间变化，δ 13 Ccarb与δ 13 Corg之间的总同位素差（Δ 13 Ccarb-org）在19.61‰ ~ 34.58‰之间变化。大多数δ 13 C org和Δ 13 Ccarb-org数据可以用光合作用来解释，可能主要是真核藻类。然而，外来有机质，最有可能是来自深海的DOC，也可能对本文研究的特定间隔的沉积有机质组成做出了贡献。此外，浅水中的高初级生产力可能在富磷条件下持续了很长一段时间，光合作用产生的有机质可能在数量上足以压倒整个埃迪卡拉纪总δ 13 Corg信号中DOC的缓冲作用。沉积物中有机物的埋藏增强将逐渐导致海洋和大气中氧气的积累，这可能为宏观动物进化铺平了道路。
Remarkable carbonate carbon isotope (δ13Ccarb) excursions accompanied by invariant organic carbon isotope (δ13Corg) values have been observed in many late Neoproterozoic successions. This decoupled relationship between δ13Ccarb and δ13Corg in the Precambrian differs from most Phanerozoic records which have been substantially imprinted by aqueous photosynthesis, and it has been tentatively interpreted as resulting from exotic organic matter inputs or diagenesis. In this study, we present high-resolution δ13Corg records in combination with previously published δ13Ccarb data from a continuous drill core from the Yangtze platform of South China. The studied interval spans the Cryogenian Nantuo Formation, the Ediacaran Doushantuo and Dengying formations, and the base of the Cambrian Yanjiahe Formation. The δ13Ccarb profile of this drill core can be reliably correlated with contemporaneous sequences and it reveals multiple negative δ13Ccarb excursions associated with phosphorite deposits. Intriguingly, the δ13Corg profile exhibits a co-varying trend with the δ13Ccarb profile, and the coupled relationship between δ13Ccarb and δ13Corg is rare in geological records of the Precambrian. The δ13Corg values of the drill core vary from −22.13‰ to −34.12‰, and the overall isotopic difference (Δ13Ccarb-org ) between δ13Ccarb and δ13Corg ranges between 19.61‰ and 34.58‰. Most of the δ13C org and Δ13Ccarb-org data can be interpreted in terms of oxygenic photosynthesis, probably mainly by eukaryotic algae. However, it is possible that exotic organic matter, most likely DOC from the deep ocean, may also have contributed to the sedimentary organic matter composition of specific intervals studied herein. Moreover, high primary productivity in shallow water may have been sustained for a long period in phosphate-rich conditions, and the organic matter generated by photosynthesis may have been quantitatively sufficient to overwhelm the DOC buffering effect in the total δ13Corg signal throughout the Ediacaran Period. The enhanced burial of organic matter in sediments would gradually result in the accumulation of oxygen, both in the ocean and atmosphere, which would likely have paved the way for macroscopic animal evolution.
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影响因子：
3.9
作者：
Ė. Galimov
通讯作者：
Ė. Galimov
藏南地区白垩纪中期碳循环扰动与海洋缺氧事件
影响因子：
4.6
作者：
Zhang X;Chen K;Hu D;Sha J
通讯作者：
Sha J
影响因子：
5.8
作者：
Chuanming Zhou;M. Huyskens;X. Lang;S. Xiao;Q. Yin
通讯作者：
Chuanming Zhou;M. Huyskens;X. Lang;S. Xiao;Q. Yin
DOI：
10.1016/j.palaeo.2009.10.024
发表时间：
2010-08
期刊：
Palaeogeography, Palaeoclimatology, Palaeoecology
影响因子：
--
作者：
K. Yamaguchi;K. Oguri;N. Ogawa;S. Sakai;S. Hirano;H. Kitazato;N. Ohkouchi
通讯作者：
K. Yamaguchi;K. Oguri;N. Ogawa;S. Sakai;S. Hirano;H. Kitazato;N. Ohkouchi
DOI：
10.1016/s0031-0182(97)00070-9
发表时间：
1997-08
期刊：
Palaeogeography, Palaeoclimatology, Palaeoecology
影响因子：
--
作者：
W. T. Holser
通讯作者：
W. T. Holser