单质硫和含硫矿物对固体沥青中生物标志物热演化过程的影响  

Effects of elemental sulfur and sulfur-bearing minerals on the thermal evolution of biomarkers in solid bitumen

作　　者：张延延 李水福[1] 胡守志[1] 方新焰 吴亮亮[2] ZHANG Yan-yan;LI Shui-fu;HU Shou-zhi;FANG Xin-yan;WU Liang-liang(Faculty of Earth Resource,China University of Geosciences,Wuhan 430074,China;State Key Laboratory of Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China)

机构地区：[1]中国地质大学(武汉)资源学院,湖北武汉430074 [2]中国科学院广州地球化学研究所有机地球化学国家重点实验室,广东广州510640

出　　处：《地球化学》2021年第3期237-250,共14页Geochimica

基　　金：十三五国家科技重大专项(2017ZX05008-002);国家自然科学基金(41972150,41672136,41572109)。

摘　　要：含硫物质与地质体中有机质的形成、演化过程密切相关,但在地质演化过程中它们对沉积有机质中生物标志物的影响较少报道。对四川盆地固体沥青样品开展在单质硫(S^(0))和含硫矿物(黄铁矿、硫酸亚铁、硫酸铁和硫酸钙)存在条件下的加水热模拟实验,进而探讨上述含硫物质在固体沥青热演化过程中对其赋存生物标志物的影响。研究表明,单质硫和含硫矿物对固体沥青中可溶有机质产率均有不同程度的影响,它们的影响程度顺序是:S^(0)>Fe_(2)(SO_(4))_(3)>FeSO_(4)>CaSO_(4)>FeS_(2)。对于反映成熟度的生物标志物参数,单质硫和含硫矿物对甾烷C_(29)-αββ/(αββ+ααα)、C_(29)-20S/(20S+20R)和藿烷C_(31)H-22S/(22S+22R)的比值均无显著影响,但对甾烷(S_(21)+S_(22))/C_(27–29)、藿烷Ts/(Ts+Tm)和规则甾烷系列比值有影响。单质硫和含硫矿物会显著改变反映生源的生物标志物参数,不同含硫物质对甾烷S_(21)/S_(22)、藿烷C_(29)H/C_(30)H、三环萜C_(23t)/(C_(21t)+C_(23t))、三环萜/藿烷比值(C_(23t)/C_(30)H)和伽马蜡烷/藿烷比值(Gam/C_(30)H)这5个指示母源的生物标志物参数的影响程度类似于其对有机质产率的影响。除S^(0)外其他含硫矿物对三环萜C_(23t)/(C_(23t)+C_(24t))比值无显著影响。因此,在对富含单质硫及含硫矿物的固体沥青进行生物标志物分析时,需要特别慎重。Sulfur compounds are closely related to the formation and evolution of sedimentary organic matter.However,few studies have reported their effects on biomarker compounds.In this study,hydrothermal simulation experiments at various temperatures were conducted on solid bitumen collected from the Sichuan Basin,together with elemental sulfur and sulfur-bearing minerals(pyrite,ferrous sulfate,iron sulfate,and calcium sulfate),to investigate the influence of elemental sulfur and sulfur-bearing minerals on the thermal evolution of biomarkers.The results showed that elemental sulfur and sulfur-bearing minerals influenced the yield of soluble organic matter from solid bitumen in the following order:S^(0)(elemental sulfur)>Fe_(2)(SO_(4))_(3)>FeSO_(4)>CaSO_(4)>FeS_(2).Elemental sulfur and sulfur-bearing minerals had little effect on the following maturity-related biomarker parameters:steranes C_(29)-αββ/(αββ+ααα),C_(29)-20S/(20S+20R),and hopane C_(31)H-22S/(22S+22R).However,other biomarker parameters,such as steranes(S_(21)+S_(22))/C_(27–29),Ts/(Ts+Tm),and the regular steranes ratio were altered.Elemental sulfur and sulfur-bearing minerals substantially changed the values of most source-related biomarker parameters,including steranes(S_(21)+S_(22)),hopane C_(29)H/C_(30)H,tricyclic terpane C_(23t)/(C_(21t)+C_(23t)),tricyclic terpane/hopane C_(23t)/C_(30)H,and gammacerane/hopane Gam/C_(30)H.The degree of influence on these five biomarker parameters was similar to the influence on the yield of soluble organic matter.However,the investigated sulfur-bearing minerals had no significant effect on tricyclic terpane C_(23t)/(C_(23t)+C_(24t)).Therefore,biomarker information obtained from solid bitumen containing elemental sulfur and sulfur-bearing minerals must be carefully considered.

关 键 词：固体沥青 热模拟实验 单质硫和含硫矿物 生物标志物 

分 类 号：P593[天文地球—地球化学] TE122[天文地球—地质学]