珠江口外近海沉积有机质化学及稳定同位素组成的早期成岩改变

张凌; 陈繁荣; 杨永强; 张德荣

珠江口外近海沉积有机质化学及稳定同位素组成的早期成岩改变

1.
中国科学院南海海洋研究所, 广东, 广州, 510301
2.
中国科学院广州地球化学研究所, 广东, 广州, 510640

基金项目: 中国科学院知识创新工程重要方向性项目:珠江河口及近海生态环境演化规律与调控机制研究(ZKCX2-SW-212)

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出版历程
- 收稿日期: 2006-12-26
- 修回日期: 2008-07-29

Chemical and isotopic alteration of organic matter during early diagenesis:evidence from the coastal area offshore the Zhujiang Estuary in China

1.
South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
2.
Guangzhou Institute of Geochemistry, Chinese Academy of Ciences, Guangzhou 510640, China

摘要

摘要: 理解早期成岩过程中有机质的化学和同位素分馏对于研究海洋和湖泊环境中的生物地球化学过程是很重要的。将珠江口外近海生物成因有机质分为可水解氨基酸、碳水化合物、脂类和酸不溶四个部分,分析了有机质的化学和同位素组成(δ¹³C,δ¹⁵N),借以讨论沉积有机质在埋藏的早期成岩过程中所发生的化学和同位素改变,结果表明,从浮游生物→悬浮颗粒物→表层沉积物→沉积柱内部,易降解组分可水解氨基酸、碳水化合物、脂类占样品总有机碳的份额依次降低。沉积物及四个有机部分的稳定碳同位素组成在纵向上随深度保持相对恒定,而在不同有机部分之间差异明显。不同类型有机物的分解速率差异在改变有机质化学成分的同时,导致其δ¹³C发生小幅度负向漂移;细菌有机质的形成和分解对有机质化学成分和同位素组成演化也有重要贡献,并且在一定程度上抵消了上述δ¹³C的负向漂移,其结果导致沉积有机质的δ¹³C略低于浮游生物;另一方面,由于异养菌生长过程中的氮同位素分馏系数与可利用氮源的特征和培养基的性质等多种因素有关,导致沉积物的δ¹⁵N变化范围增大。在这里δ¹³C可以可靠地指示该海域沉积有机质的来源,而δ¹⁵N变化范围较大且规律不明显,难以用作沉积有机质来源的指示。
- 有机碳含量 /
- 稳定碳、氮同位素组成 /
- 早期成岩 /
- 分馏 /
- 细菌 /
- 珠江口
Abstract: Under standing the chemical and isotopic alteration of organic matter duringearly diagenesis is crucial to the studies of biogeochemical processes in marine and lacustrine environments.The isotopic composition(δ¹³C and δ¹⁵N),total organic carbon(TOC)and total nitrogen(TN)contents of sediment cores as well as plankton and suspended particulates from the coastal area off shore the Zhujiang Estuary were determined,and the fractional carbon content of total hydrolysable amino acids(THAA),total carbo hydrates(TCHO),total lipid and acid-insoluble organic compounds(AIOC)and their respective δ¹³C were analyzed,based on which,the magnitude and mechanismof chemical and isotopic fractionation of organic matter were investigated.Results showed that the degradable fractions of THAA、TCHO and lipid decreased from plankt on to POM to surface sediments and to the buried sediments,and δ¹³C of TOC and organic fractions kept stable with depth,but differed distinctly among the four fractions.The different degradation rates oforganic compounds and the formation and degradation of bacteria organic matterare the major mechanisms causing the chemical and isotopic alteration oforganic matter duringearly diagenesis1 Because of the lower carbohydrate content in the plankton and the rapid degradation of lipid,the carbon isotopic fractionation caused by selective degradation of compounds could be relatively small and was partially canceled by the addition of bacterial synthesized organic matter,resultingin the observed conservative nature of δ¹³C duringearly diagenesis.On the other hand,the addition of bacteria organic matter may account for the depletion and variation of δ¹⁵N caused by early diagenesis.The above studies suggested that δ¹³C can be a reliable proxy to the sources of organic matter,but δ¹⁵N cannot be used to indicate the origin of sedimented o rganic matterin the study area.
- TOC /
- stable isotopic composition /
- early diagenesis /
- fractionation /
- bacteria activity /
- Zhujiang Estuary in China

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参考文献(22)

WAKEHAM S G,LEE C,HEDGES J I,et aL Molecular indicators of diagenetic status in marine organic matter[J].Geochimica et Coamochimica Acta,1997,61:5363-5369.

WANG X-C,DRUFFEL E R M,GRIFFIN S,et al.Radiocarbon studies of organic compound classes in plankton and sediment of the northeastern Pacific Ocean[J].Geochimiea et Cosmochimiea Aeta,1998,62(8)z1365-1378.

鲜本忠,吴战国,姜在兴.早期成岩作用研究进展及发展方向[J].石油大学学报(自然科学版),2004,28(6):133-139.

HOLCOMBE B L,KEIL R G,DEVOL A H.Determination of pore-water dissolved organic carbon fluxes from Mexico margin sediments[J].Limnology and Oceanography,2001,46:298-308.

MARTIN W R,BENDER M,ORCHARDO J.Benthic organic carbon degradation and biogenic silica dissolution in the central equatorial Pacific[J].Deep Sea Research,1991,38:1481-1456.

HENRICHS S M,FARRINGTON J W.Early diagenesis of amino acids and organic matter in two coastal marine sediments[J].Geochimica et Cosmochimica Acta,1987,51(1):1-15.

MCARTHUR J M,TYSON R V,THOMSON J,et al.Early diagenesis of marine organic matter:alteration of the carbon isotopic composition[J].Marine Geology,1992,105:51-61.

MACKO S A,ENGEL M H,HARTLEY G,et al.Isotopic compositions of individual carbohydrates as indicators of early diagenesis of organic matter[J].Chemical Geology,1991,931147-161.

COWIE G L,HEDGES J I.Biochemical indicators of diagenetic alteration in natural organic matter mixtures[J].Nature,1994,369:304-307.

FREUDENTHAL T,WAGNER T,WENZHFER F,et al.Early diagenesis of organic matter from the eastern Atlanticz evidence from stable nitrogen and carbon isotopes[J].Geochimica et Cosmochimica Acta,2001,65:1795-1808.

GRUTTERS M,RAAPHORST W V,HELDE R.Total hydrolysable amino acid mineralization in sediments across the Atlantic continental slope (Goban Spur) EJ].Deep-Sea Research (I),2001,48(3):811-832.

LEHMANN M F,BERNASCONI S M,BARBIERI A.Preservation of organic matter and alteration of its carbon and nitrogen isotope composition during simulated and in situ early sedimentary diagenesis[J].Geochimica et Cosmochimica Acta,2002,66:3573-3584.

LEE C,CRONIN C.The vertical flux of particulate organic nitrogen in the sea:decomposition of amino acids in the Peru upwelling area and the equatorial Atlantic[J].Journal of Marine Research,1982,40:227-251.

HENRICHS S M,FARRINGTON J W,LEE C.Peru upwelling region sediments near 15°S:Ⅰ.Remineralization and accumulation of organic matter[J].Limnology and Oceanography,1984,29:1-19.

SIGLEO A C.Biochemical components in suspended particles and colloids:carbohydrates in the Potomac and Patuxent Estuaries[J].Organic Geochemistry,1996,24 (1):83-93.

OGLER S,DISNAR J R,AIB RIC P,et al.Neutral carbohydrate geochemistry of particulate material (trap and core sediments) in a eutrophic lake (Aydat,France)[J].Organic Geochemistry,2001,32(1):151-162.

COWIE G L,HEDGES J I.Carbohydrate sources in a coastal marine environment [J].Geochimica et Cosmochimica Acts,1984,48:2075-2087.

张凌.珠江口及近海沉积有机质的??刁?????匟?????????丮乿????獢潿瓞漰瀃椖捦—晶牀愬挲琰椰漶渮愼瑂楒漾湛?搹畝爠楈湅李?灉敃灈瑓椠摓攠?戬潄湏摙?桅礠摁爠潐氮祄獥楣獯孭?嵯??整潩捯桮椠浯楦挠愼?敵瑰￣?漴猼洯潳捵桰椾浃椭捬慡??捬瑥慤?????????????????????????割?孮?ㄠ嵳?佤卩呭剥佮??乛???????佯?卯????????????敯瑧?慡汰?卹攬愱猹漸渶愬氳?瘹愨爴椩愺琷椶漵渭?椷游?琼桂敒￣獛琲愰扝氠效?捄慇牅打漠湊?慉測摃?湁楒瑋爠潗朠敁測?楏獗潉瑅漠灇攠?戮楆潬杵數潥捳栠敡浮楤猠瑲牥祡?潴晩?慩?捩潥慳猠瑯慦氠?捲潧污摮?潣挠敭慡湴?敥湲瘠楩牮漠湡洠散湯瑡孳?嵡??敭潡敲桩楮浥椠换慡?敛瑊??潌獩浭潮捯桬楯浧楹挠慡??挠瑏慣?????????????劳?水??㈨??呼???刷?嬱?特崲?????佛′匱????卙呅?偓????????楉捅爠潂戠楊愮汓?慵汲瑣敥牳愬瑤楥潧湲?潤晡?獩瑯慮戠污敮?渠楲瑥牣潹杣敬湩?慧渠摯?挠慯牲执潡湮?楣猠潭瑡潴灴楥捲?捡潳浳灯潣獩楡瑴楥潤渠獷?潴晨?潳物杮慫湩楮捧?浰慡瑲瑴敩牣孬?嵳?佩牮朠慌湡楫捥??敩潣捨桩敧浡楮獛瑊牝礮??????????????ね???割?嬬??崹″??‰丱?刴伷??????偒匾呛??九?午??敖捅桙愠湈椠獒洬?潕晔?捌慅爠扊漠湈?楂獅潌瑌漠灊攠?昮牋慩敮瑥楴潩湣慳琠楯潦渠?慨獹獴潯捰楬慡瑮敫摴?睮椠瑤桥?污楹瀠楤摵?獩祮湧琠桳敩獭極獬?汴??崠??卤捩業敥湮捴敡????????????ㄠ???????剨?孭??嵡?????佰?即????卮吠?偮?????????剡??偡???敶瑩?慹氠??獤潥瑲漠灯楸捩?映牡慮捤琠楡潮湯慸瑩楣漠湣?慮湤摩?捩慯牮扳潛湊?椮獇潥瑯潣灨楩捭?捣潡洠灥潴猠楃瑯楳潭湯獣?潩晭?潣牡朠慁湣楴捡?洱愹琹琵攬爵?椨渱?琩栺攳″猶礷渭琳栳攷猷椮猼?潒显?愲洳楝渠潂?慒捉楘搩獗?手祉?洠楏挠牋漮潓牯杵慲湣楥獳洠孯?崠??桧敡浮楩獣琠牭祡??敥潲氠潩杮礠?????????????????前?孲??嵥?升??乬佯?呹???吶吵伬刳?‵???攮漼杂牒愾灛栲椴捝愠求?癒慄牏楗慓瑋楉潙渠?漠晋?瑁档散?睭慵瑬敡牴?捯潮氠畯浦渠?摲楧獡瑮物楣戠畭瑡楴潴湥?漠晩?猠畢獯灴整湯摭攠摳摥?灩慭牥瑮楴捳畛汊慝琮敍?潲物杮慥渠楇捥?湬楯瑧特漬朱改渶‵愬渳携″椳琭猸′?猼畂灒?????猠界灅?乍?湎慎琠畍爠慆氬?慅扒畎湁摓慃湏捎敉?楓渠?琬桂敁?偂慉捅楒晉椠捁?慐湲摥?楥瑲獶?浴慩牯杮椠湯慦氠?獲敧慡獮孩?崠??整整灥?匠敡慮?删敡獬??偲慡牴瑩??????????????????の????????剥?嬠??嵯?卯???卣???偯?剩?偩?呮???????传?剩?????剥?丠楡瑮牤漠杩敮渠?慩湴摵?捥慡牲扬潹渠?楥獤潩瑭潥灮楴捡?特愠瑤楩潡獧?潮晥?捩桳汛潊牝漮灇桥祯汣汨?晭物潣浡?浥慴爠楃湯敳?灯档票瑩潭灩汣慡渠歁瑥潴湡嬬?崰??攬漶挶栺椳洵椷挳愭″攵琸??漼獂浒漾捛栲椶浝椠捓慗??捎瑅慙??????????????????????l abundances of ¹⁵N as a source indicator for near-shore marine sedimentary and dissolved nitrogen[J].Marine Chemistry,1980,9:81-94.

DEGENS E T,BEHRENDT M,GOTTHARDT B,et al,Metabolic fraetionation of carbon isotopes in marine plankton:Ⅱ.Data on samples collected off the coasts of Peru and Ecuator[J].Deep-Sea Research,1968,15:11-20.

DE NiRO M J,EPSTEIN S.Mechanism of carbon isotope fractionation associated with lipid synthesis[J].Science,1977,197:261-263.

MONSON K D,HAYES J M.Carbon isotopic fractionation in the biosynthesis of bacterial fatty acids.Ozonolysis of unsaturated fatty acids as a means of determining the intramoleeular distribution of carbon isotopes[J].Geochimica et Cosmochimica Acta,1982,46:139-149.

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