黔北下寒武统牛蹄塘组烃源岩的生物标志物 特征和沉积环境   总被引：1，自引：0，他引：1  

杨平  汪正江  谢渊  杜秋定  陈厚国  贺永忠 《地质通报》2012,31(11):1910-1921

为研究黔北地区下寒武统牛蹄塘组烃源岩母质来源和沉积环境,开展了生物标志化合物分析,结果表明：①正构烷烃OEP接近1.0,无明显奇偶优势,受轻微生物降解影响,正构烷烃多表现为双峰型(C18/C25),(nC21+nC22)/(nC28+nC29)值为0.54~1.01,显示重烃组分占绝对优势;Pr/Ph值范围在0.51~0.82之间,具有植烷优势。②烃源岩样品组成相对丰度五环三萜烷>三环萜烷>四环萜烷,三环萜烷中C21、C23、C24呈倒V字形分布,Ts/(Tm+Ts)为0.45~0.50。③C27规则甾烷/C29规则甾烷略小于1或者接近1,芳烃化合物DBT/P为0.05~0.09。根据这些特征并结合干酪根同位素及正构烷烃同位素组成和变化规律,认为该区域下寒武统牛蹄塘组烃源岩形成于浅海还原环境,且有机质主要来源于细菌、藻类等低等水生生物,有机质热演化程度较高。根据常量、微量元素指标并结合有机地化指标刻划出从灯影组到牛蹄塘组和明心寺组沉积时期的水体环境,将牛蹄塘组烃源岩的形成分为3个阶段,第一阶段为早寒武世初始快速海侵阶段,第二阶段为深水还原高有机质产力阶段,第三阶段为海水缓慢变浅高有机质产力阶段,而到了明心寺组沉积时期为浅水氧化非烃源岩阶段。  相似文献   

四川盆地龙潭组高热演化烃源岩有机质生源及沉积环境探讨   总被引：4，自引：0，他引：4  

朱扬明  顾圣啸  李颖  郝芳  邹华耀  郭彤楼 《地球化学》2012,(1):35-44

四川盆地龙潭组烃源岩R°值主要变化在2.0％～3.0％范围,干酪根H/C原子比值多数集中在0.3～0.5之间,有机质热演化达到过成熟阶段.它们的各类饱和烃生物标志物组成和分布大都发生了异常变化,限制了其地球化学应用.其芳烃组分和干酪根碳同位素及S、N元素组成还包含着标志有机质生源及沉积环境的信息.川东南地区近海湖沼相含...  相似文献   

Quantitation of metallothionein mRNA from the New Zealand common bully (Gobiomorphus cotidianus) and its implications for biomonitoring     

Andrew D. Laurie 《新西兰海洋与淡水研究杂志》2013,47(5):869-877

Metallothionein (MT) is a protein found in most eukaryotes where its primary role is the regulation of homeostasis of the essential metals copper and zinc. MTs have an additional protective role through their binding of toxic metals such as cadmium and mercury. Increased expression of MT in response to harmful levels of these metals has been demonstrated for several aquatic species. In this study, the expression of MT in the liver tissue of the New Zealand common bully Gobiomorphus cotidianus was measured by quantifying MT mRNA. A statistically significant increase in MT expression was observed in fish exposed to copper for 48 h, but not those exposed to zinc. Field sampling of common bullies showed a wide variation in individual hepatic MT mRNA levels which did not correlate with fish age, sex, or sampling location. A comparison of two populations of common bullies from a polluted and a control site showed a two‐fold higher mean MT mRNA level in fish from the polluted site. Implications for using MT expression in the common bully as a bio‐monitoring tool are discussed.  相似文献   

云南金顶铅锌矿床的生物标志物特征及意义   总被引：1，自引：0，他引：1  

周玉华  朱利东  付修根 《矿物岩石》2007,27(2):47-53

采用GC-MS分析方法对金顶铅锌矿床进行研究,结果表明:该矿床正构烷烃呈前高后低的单峰型分布,nC16或nC22为主峰碳,轻烃组分占有绝对优势,OEP值0.837～0.976,接近平衡值1.00,Pr/Ph为0.1～0.88,显示植烷优势;萜烷丰度顺序为五环三萜烷>三环萜烷>四环萜烷;规则甾烷呈不对称的“V”字形分布,表现为C29>C27>C28的分布特征。这些特征显示,金顶铅锌矿床有机质(生物)来源物质以菌藻类生物为主,可能有部分高等植物的贡献;矿床形成于缺氧的高盐度环境。结合金顶铅锌矿床下含矿层(原地沉积岩系)沉积于水深较浅的蒸发盐湖环境(即氧化环境),可以推断该矿床成矿流体中丰富的有机质形成的还原条件以及外来推覆岩系形成的封闭条件是金顶铅锌矿床形成的必要条件,矿床属于后期充填作用为主的矿床。  相似文献   

The Biomarkers in the Mesoproterozoic Organic-rich Rocks of North China Craton: Implication for the Precursor and Preservation of Organism in the Prokaryotic Realm     

MA Sihong  ZHANG Shuichang  SU Jin  WANG Xiaomei  HE Kun  FANG Yu  MI Jingkui 《《地质学报》英文版》2022,96(1):293-308

Mesoproterozoic marine organic-rich rocks are widely distributed in the North China Craton,include the Gaoyuzhuang(GYZ),the Hongshuizhuang(HSZ),and the Xiamaling(XML)formations.According to the T;value and isomerisation ratio of C;homohopanes,the XML,HSZ,and GYZ samples were in low mature,mature and high mature stage,respectively.Biomarker distribution in extractable organic matter(EOM)of three Mesoproterozoic organic-rock samples in different maturity were analysed to reveal the organic precursor and preservation pathway of in the Mesoproterozoic Combined with gold-tube pyrolysates of three Mesoproterozoic samples,it could further illuminate the chemical composition of Mesoproterozoic kerogen,given excluding.The results indicated that the three formations were all deposited under reducing condition and their organic precursors mainly were some aquatic organisms.High content of rearranged hopanes was detected in EOM of XML and HSZ samples,whereas they were relatively low in the high mature GYZ sample.Contrast to that in EOM,the relative concentration of rearranged hopanes sharply decreased in the gold-tube pyrolysates of the XML kerogen,then slightly increased but was still significantly lower than the EOM of XML sample,which indicated that catalysis of clay minerals in the early diagenesis only changed the chemical composition of the unstable functional groups of the kerogen during the preservation.Due to the thriving heterotrophic microbes and low sink rate of particulate organic matter during the Mesoproterozoic,primary producers suffered extensive degradation during sinking process,only some resistant biopolymers lacking of lipid compounds survived from heterotrophic degradation,while heterotrophic microbes contained more proportion of organic precursors.Abundant pristane(Pr)and phytane(Ph)were only released in high mature stage because of the protection of the macromolecular structure of resistant biopolymers which prevented biomarkers from being altered by the thermal stress.The absence of 13α(n-alkyl)-tricyclic terpanes in the high matured hydrocarbon products also indicated the different precursors between different parts of Mesoproterozoic kerogen.The evolution of the biomarker composition and content of Mesoproterozoic kerogen showed some special characteristics differing from those of Phanerozoic kerogen.The total concentrations of hopanes displayed with an order of low mature stage>high mature stage>mature stage.Relative content of rearranged hopanes in the hydrocarbon generated in high mature stage was significantly lower than that in the low maturity stage.The ratios of Pr/n-C₁₇ and Ph/n-C₁₈ increased with thermal maturity,and the ratio of nC_21-/nC₂₂₊ decreased in the high maturity stage,thus displaying another order of mature stage>high maturity stage>low maturity stage.The unique preservation pathway of Mesoproterozoic organisms was attributed to the special evolution characteristics of biomarker distributions,which should be considered in the Mesoproterozoic marine environment and biological studies.  相似文献