沉积岩中不同形态氮的提取方法及其在古环境研究中的意义  

Extraction Methods of Different Forms of Nitrogen from Sedimentary Rocks and Their Significance in Palaeo-environmental Research

作　　者：邢腾 朱园园 李靖 王诗宇 杜勇[1] 邱海鸥 宋虎跃[1] XING Teng;ZHU Yuan-yuan;LI Jing;WANG Shi-yu;DU Yong;QIU Hai-ou;SONG Hu-yue(State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan 430074,Hubei,China;Hubei Key Laboratory of Paleontology and Geological Environment Evolution,Wuhan 430223,Hubei,China;Faculty of Materials Science and Chemistry,China University of Geosciences,Wuhan 430074,Hubei,China)

机构地区：[1]中国地质大学(武汉)生物地质与环境地质国家重点实验室,湖北武汉430074 [2]古生物与地质环境演化湖北省重点实验室,湖北武汉430223 [3]中国地质大学(武汉)材料与化学学院,湖北武汉430074

出　　处：《地球科学与环境学报》2023年第4期941-952,共12页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(41872033,42172032)。

摘　　要：近年来,沉积岩中的氮同位素组成(δ^(15)N)已成为生命起源和古环境研究的有效地球化学指标,并为这些领域的原创性发现提供了重要科学证据。沉降的有机质在经过生物地球化学过程和地质作用的改造后转化为不同形态的含氮物质(如干酪根结合氮、可溶性有机氮以及NH^(+)_(4)等),并保存于沉积岩中。不同形态氮可能具有独特的古环境意义,有必要进行单独的分离和提取,丰度较低的氮组分(如固定铵)也逐渐得到重视。当前,学者们主要利用全岩和干酪根的氮同位素组成开展相关研究工作,但由于地质过程复杂,特定含氮物质提取同位素测试和解译难度较高,何种形态的氮能代表原始的古海水信号尚不明确。在前人研究的基础上,归纳了含氮物质在不同地质作用中的演化历程,系统总结了沉积岩中不同形态氮的提取方法,阐明了它们的古环境意义,并对不同形态氮应用于古环境研究存在的问题进行了讨论;同时,提出古海洋氮循环研究亟需开展的工作,为推动氮同位素的高精度测试及古环境研究提供参考。In recent years,the nitrogen isotopic composition of sedimentary rocks has become a valid geochemical proxy in the origin of life and palaeo-environmental research,providing important evidence for the original discoveries in these fields.Sedimentary organic nitrogen is transformed into different species(such as kerogen-bound nitrogen,soluble organic nitrogen,and NH^(+)_(4))during biogeochemical and geological processes,and is contained in sedimentary rocks.Different forms of nitrogen may have unique palaeo-environmental significance,necessitating separate isolation and extraction.Less abundant nitrogen fractions(such as fixed ammonium)are also gaining attention.At present,researchers mainly use the nitrogen isotopic composition of whole rock and kerogen for palaeo-environmental interpretations.However,due to the complex geological processes,it is difficult to extract and analyze compound-specific nitrogen isotopes.And it is uncertain which nitrogen species more faithfully record the original seawater signal.Here the evolution process of nitrogenous substances in different episodes of geological processes,the extraction methods of different nitrogen species,and the palaeo-environmental significance of different forms of nitrogenous substances are summarized,and the problems in palaeo-environmental research are discussed.And some suggestions for the follow-up work of the palaeo-marine nitrogen cycle research are presented for the reference of the high-precision palaeo-environmental research of nitrogen isotopes.

关 键 词：古环境 古海洋 氮循环 沉积岩 稳定氮同位素 干酪根 固定铵 可溶性有机氮 

分 类 号：P736.4[天文地球—海洋地质]