Preliminary study of fluxes of major lipid biomarker classes in the water column and sediments of Lake Baikal, Russia     

Marie Russell  Antoni Rosell-Mel 《Global and Planetary Change》2005,46(1-4):45

The application of biomarker climate proxies to lacustrine settings requires a thorough understanding of those processes that give rise to and mediate in the burial and preservation of organic matter in the sediments. This information is to date missing for Lake Baikal in Central Asia. The biogeochemistry of the lake cannot be considered analogous to that in other lacustrine environments given its enormous size, depth, remote location and unique biology. The aim of this paper is to report on the main compound classes in the water column and sediments. As part of an ongoing evaluation of the inputs and fluxes of organic matter in Lake Baikal, we have found that there are significant differences in the inputs and preservation of organic matter between the North and South Basins. Both basins have dominant algal input and a contribution from the terrestrial plants of the lake edges and surrounding environments. However, the concentration of organic material in the sediment traps and sediments of the South Basin is much higher than that of the North Basin. In addition, the South Basin contains much higher proportions of the more labile material than does the North Basin. This is likely due to the South Basin being free of surface ice for a much longer time than the North, and in consequence, primary producers having an overall longer productive season. There is some evidence of microbial activity in the sediment traps and sediments from both the North and South Basins, but it does not appear to be more predominant in one basin than the other. It is probable that the differences in the composition and concentration of biomarkers in sediments between basins is due to the length of and the intensity of the productive season, which is in turn influenced by the climate.  相似文献   

塔里木盆地塔东2井寒武系稠油地球化学特征与成藏   总被引：1，自引：0，他引：1  

唐友军 《沉积学报》2009,27(6):1208-1215

剖析塔东2井稠油的地球化学特征与形成过程,对深化塔里木盆地海相原油的成藏特征具有重要的意义。综合运用碳同位素、色谱、色谱—质谱等技术手段研究了塔东2井寒武系稠油的特征,研究结果揭示塔东2井寒武系稠油具高伽马蜡烷、高C28甾烷、低重排甾烷和高C27 三芳甾烷的特征,与寒武系—下奥陶统烃源岩的分子特征类似,说明塔东2井寒武系原油源自寒武系—下奥陶统烃源岩;塔东2井稠油中检出高丰度的稠环化合物（荧蒽、芘、苯并\[a\]蒽、屈、苯并荧蒽、苯并芘）,及全油的碳同位素值明显偏重,揭示了原油烃类经热蚀变发生稠化;流体包裹体均一化温度和埋藏—热演化史分析确定了塔东2井原油的成藏期为450~440 Ma。  相似文献   

江陵凹陷西南部梅槐桥富生烃洼陷及近源油气成藏   总被引：2，自引：2，他引：0  

易积正  何生  刘琼  耿锋 《地质科技情报》2009,28(1)

江陵凹陷西南部已发现的油气藏紧邻梅槐桥富生烃洼陷分布,且油气储量主要集中在该洼陷生烃中心短轴方向两侧的谢凤桥、南岗、复兴场、采穴等断块和断鼻圈闭中.对梅槐桥富生烃洼陷内烃源岩发育特征及其洼陷内生烃差异性的研究表明:洼陷北部梅槐桥地区是烃源岩沉积时期的沉降中心,烃源岩发育,埋藏较深,生烃能力强,为该洼陷的生烃中心;而南部牛头岗地区烃源岩层厚度小,埋藏浅,生烃能力差.原油成熟度和油源对比研究表明,油气具有近距离运移近源成藏的特点;北部采穴断块、复I断块、谢凤桥断鼻和南岗断鼻油气藏中成熟度相对较高的原油主要来自北部梅槐桥地区;南部八宝断鼻油气藏中成熟度低的原油与牛头岗地区原地烃源岩具有亲缘关系;而偏南部丁家湖断鼻油气藏中的原油则为梅槐桥生烃中心成熟度较高的烃源岩和原地烃源岩的混合贡献的原油.因此,可认为梅槐桥生烃中心短轴方向的两侧为目前江陵凹陷西南部油气勘探最有利的地区.  相似文献   

Acyclic Alkanes in the Cave in Qingjiang, Soil over Heshang Hubei Province     

蒲阳黄俊华  黄咸雨崔景伟 胡超涌 《中国地质大学学报(英文版)》2006,17(2):115-120

The reports that relate to the biomarker＇s fate and characteristics of the modern soil in the karst area are very lacking. By using gas chromatography-mass spectrometry （GC-MS）, a series of biomarkers were identified from the soils collected over Heshang cave （和尚洞） in Qingjiang （清江）, Hubei （湖北） Province. The distribution of n-alkanes is mainly from C2s to C33 in carbon number, with a maximum at C31. They have a strong odd-over-even carbon number predominance. These characteristics represent an input mainly from higher plants. The lipid parameters, including CPIh （carbon preference index）, Rb/t（ratio of lower- to higher-molecular-weight homologues） and ACL （average chain length）, show comparable trends with depth, probably reflecting vegetation change and microbial degradation. Series of monomethylalkanes and diploptene are present in the extractable organic matter; they might be derived from soil microbes, cyanobacteria in particular.  相似文献   

桦甸盆地桦甸组与美国犹他盆地绿河组油页岩生物标志化合物特征对比   总被引：2，自引：0，他引：2  

孟庆涛  刘招君  柳蓉  孙平昌  胡菲  张京 《吉林大学学报(地球科学版)》2011,41(2):391-399

在野外地质考察、岩心观察和大量测试数据分析的基础上,对我国东北地区桦甸盆地始新统桦甸组和美国犹他盆地始新统绿河组油页岩中类异戊二烯烷烃、甾类和萜类等生物标志化合物特征进行了详细的对比研究,并探讨其对两地油页岩在有机质来源及古沉积环境上的差异指示意义。结果表明:在GC谱图上,桦甸油页岩Pr/Ph为1.47～2.03,具姥鲛烷优势;而绿河油页岩Pr/Ph为0.34～0.44,具植烷优势。GC-MS分析表明:桦甸油页岩规则甾烷C27-C28-C29呈反"L"型分布,∑(C27+C28)/∑C29为0.63～2.52;绿河油页岩规则甾烷C27-C28-C29呈钝角不对称"V"型分布,∑(C27+C28)/∑C29为0.96～1.20。桦甸油页岩萜类化合物中萜烯>ββ构型霍烷>αβ构型霍烷,以C29萜烯占优势;绿河油页岩中五环三萜烷>三环萜烷>四环萜烷,并检出丰富的γ-蜡烷和β-胡萝卜烷。两地油页岩生物标志化合物特征参数的对比分析揭示:桦甸油页岩为水生生物和高等植物双重生源,但细菌及藻类等水生生物的贡献较大,主要形成于弱还原淡水沉积环境;绿河油页岩有机质来源主要为细菌和藻类等水生生物,主要形成于强还原咸水沉积环境。  相似文献   

泌阳凹陷第三系湖相泥质白云岩中特殊甾烷化合物分布特征及地球化学意义   总被引：1，自引：2，他引：1  

陈军红  傅家谟  盛国英 《地球化学》1995,(4)

在研究羊毛甾烷的基础上，又从泌阳凹陷第三系湖相泥质白云岩地层中检测出了其他系列的特殊甾烷化合物，如３β－乙基甾烷（Ｃ（２９）－Ｃ（３１）），３β－正丙基甾烷（Ｃ（３０）－Ｃ（３２））和３β－丁基甾烷（Ｃ（３１）－Ｃ（３３））和甲藻甾烷等。这些特殊甾烷集中出现的情况曾未报道过。除母源输入具有特殊组合外，水体较高盐度和强还原环境可能是这些化合物得以保存的重要原因。  相似文献   

宣龙式铁矿生物标志物（烷烃）的研究   总被引：4，自引：0，他引：4       下载免费PDF全文

刘志礼  杜汝霖 《地质学报》1995,69(2):138-145

笔者通过对河北庞家堡碾盘山，大堡堆和龙关共８个铁矿岩样的生物标志物（烷烃）的研究，发展这些样品中ｎＣ１５－ｎＣ２０含量较高，主峰碳都在ｎＣ１６、ｎＣ１７、ｎＣ１８；植烷，姥鲛烷很丰富。这些结果表明矿体中的铁质叠层石和铁质核形石是藻成沉积构造。聚铁作用的发生主要是蓝藻生命活动所引起。该研究结果为宣龙式乌托邦成因提供了新的价值的证据。  相似文献   

Biomarkers (Alkanes )of the Xuanlong - Type Iron Deposits     

Liu Zhili  Liu Xuexian  Li Pengfu Department of Biology  Nanjing University  Nanjing  Jiangsuand Du Rulin Hebei College of Geology  Shijiazhuang  Hebei Fei Zhenbi 《《地质学报》英文版》1995,69(4):387-395

The authors studied the biomarkers (alkanes) of eight iron ore samples from Nianpanshan and Dsbaodui of Pangjiabao and Longguan, Xuanhua, Hebei. These samples have higher nC15-nC20 contents, with main peaks at nC16, nC 17 and nC18, and contain abundant pristane and phytane. These results indicate that iron stromatolite and iron oncolites in orebodies are sedimentary structures of algal origin. Sedimentary iron accumulation mainly results from activity of blue algae. This study provides new valuable evidence for the origin of Xuanlong-type iron deposits.  相似文献   

生物标志物地球化学的新进展   总被引：11，自引：3，他引：11  

陈建渝 《地质科技情报》1995,14(1):35-44

生物标志物地球化学是７０年代以来迅速发展起来的分支学科。它通过分析生物标志物的化学组成及构型转化来研究沉积有机质的演化及沉积矿产特别是石油的成因。本文以我国东部油田下第三系生油岩及原油中生物标志物的分布为例，简介了它们为油气勘探提供有关有机质来源、沉积环境、成熟度、油气运移及生物降解等多方面信息的重要作用及其新的进展。  相似文献   

Organic Composition of Sulphide Ores in the Okinawa Trough and Its Implications   总被引：1，自引：0，他引：1  

ZHANG Qiling  HOU Zengqian  TANG ShaohuaInstitute of Mineral Deposits  Chinese Academy of Geological Sciences Baiwanzhuang Ro  Beijing 《《地质学报》英文版》2001,75(2):196-203

A preliminary organic geochemical study shows that the sulphide ores from the hydrothermal deposit of the Okinawa Trough are generally low in the total organic carbon and extremely low in the soluble organic matter. In the aliphatic hydrocarbon fraction, the n-alkanes range from C15 to C35, with usual maxima in the middle n-C20 region and strong odd-carbon number predominance when n > C25 (CPI = 1.2). The dominant analog in the aromatic fraction is phenanthrene, a polynuclear aromatic hydrocarbon, which provides evidence for hydrothermal activity. The organic matter derived mainly from marine planktonic and terrigenous vascular plants is entrapped in a high-temperature regime such as an active chimney and cooled quickly in the sulphide ores on the seafloor. Organic matter and sulphides are definitely products of a high-temperature alteration. The biomarker compounds indicate that the ores are formed under low Eh and pH conditions-a reducing to anoxic environment, which is favourable for sulphates to be  相似文献