四川盆地北缘下寒武统页岩生物标志化合物特征及其地质意义
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摘要
针对四川盆地绵阳—长宁拉张槽北段米仓山地区下寒武统筇竹寺组黑色页岩开展了系统的有机地球化学分析,以正构烷烃、类异戊二烯烃、萜类化合物、甾类化合物等生物标志化合物为重点,探究绵阳—长宁拉张槽的成因机理及沉积环境。扬子板块北缘下寒武统黑色页岩中的有机质主要来自低等浮游生物与细菌的共同贡献;盐度一定的情况下,分层的海水不仅为水体表层浮游生物的繁殖发育提供良好环境,还给厌氧的喜盐细菌的繁殖提供了有利条件;筇竹寺组黑色页岩中检测出的4-甲基甾烷为典型热液喷口微生物的分子化石,其产出为绵阳—长宁拉张槽的拉张成因提供了证据。据此构建了该区古海洋模型,甲烷氧化菌、硫酸盐还原菌等热液喷口微生物,不仅为有机质提供了生物来源,还促进了浅部水体藻类的繁殖,提高了古生产力。
The formation of the sag in the central Sichuan Basin may have influenced the development of major reservoir and source rock formations, such as the Lower Cambrian Qiongzhusi(Niutitang) Formation. This study analyzed the organic geochemistry, including n-alkanes and isoprenoids, steranes, terpanes(hopanes series), of organic matter in the Qiongzhusi Formation on the northern margin of the Yangtze Plate to investigate the depositional environment and formation mechanism of the intracratonic sag. The results indicate that the organic matter in the study area was sourced from eukaryotic phytoplankton and bacteria. The presence of gammacerane and low pristane/phytane ratios indicates that the top of the water column contained enough oxygen to provide favorable conditions for eukaryotic phytoplankton to thrive. The presence of 4-methyl steranes, a typical molecular indicator of hydrothermal vent microbes, in the Qiongzhusi Formation suggests anaerobic organisms thrived at the bottom of the water column as a result of extension during the formation of the intracratonic sag. A paleoceanographic model of the study area was constructed. Both methane oxidizing and sulfate reducing bacteria along with other hydrothermal vent microbes may not only serve as sources of organic matter, but also promote the propagation of algae in shallow water to improve organic productivity in this ancient environment.
The formation of the sag in the central Sichuan Basin may have influenced the development of major reservoir and source rock formations, such as the Lower Cambrian Qiongzhusi(Niutitang) Formation. This study analyzed the organic geochemistry, including n-alkanes and isoprenoids, steranes, terpanes(hopanes series), of organic matter in the Qiongzhusi Formation on the northern margin of the Yangtze Plate to investigate the depositional environment and formation mechanism of the intracratonic sag. The results indicate that the organic matter in the study area was sourced from eukaryotic phytoplankton and bacteria. The presence of gammacerane and low pristane/phytane ratios indicates that the top of the water column contained enough oxygen to provide favorable conditions for eukaryotic phytoplankton to thrive. The presence of 4-methyl steranes, a typical molecular indicator of hydrothermal vent microbes, in the Qiongzhusi Formation suggests anaerobic organisms thrived at the bottom of the water column as a result of extension during the formation of the intracratonic sag. A paleoceanographic model of the study area was constructed. Both methane oxidizing and sulfate reducing bacteria along with other hydrothermal vent microbes may not only serve as sources of organic matter, but also promote the propagation of algae in shallow water to improve organic productivity in this ancient environment.
引文
[1] WEI Guoqi,YANG Weiqi,DU Jinhu,et al.Geological features of Sinian-Early Cambrian intracratonic rift of the Sichuan Basin[J].Natural Gas Industry B,2015,2(1):37-48.
[2] LIU Shugen,DENG Bin,JANSA L,et al.The Early Cambrian Mianyang-Changning intracratonic sag and its control on petroleum accumulation in the Sichuan Basin,China[J].Geofluids,2017,2017:6740892.
[3] 刘树根,孙玮,罗志立,等.兴凯地裂运动与四川盆地下组合油气勘探[J].成都理工大学学报(自然科学版),2013,40(5):511-520.LIU Shugen,SUN Wei,LUO Zhili,et al.Xingkai taphrogenesis and petroleum exploration from Upper Sinian to Cambrian Strata in Sichuan Basin,China[J].Journal of Chengdu University of Technology (Science & Technology Edition),2013,40(5):511-520.
[4] ZOU Caineng,DU Jinhu,XU Chunchun,et al.Formation,distribution,resource potential,and discovery of Sinian-Cambrian Giant Gas Field,Sichuan Basin,SW China[J].Petroleum Exploration and Development Online,2014,41(3):306-325.
[5] 周慧,李伟,张宝民,等.四川盆地震旦纪末期—寒武纪早期台盆的形成与演化[J].石油学报,2015,36(3):310-323.ZHOU Hui,LI Wei,ZHANG Baomin,et al.Formation and evolution of Upper Sinian to Lower Cambrian intraplatformal basin in Sichuan Basin[J].Acta Petrolei Sinica,2015,36(3):310-323.
[6] 杨雨,黄先平,张健,等.四川盆地寒武系沉积前震旦系顶界岩溶地貌特征及其地质意义[J].天然气工业,2014,34(3):38-43.YANG Yu,HUANG Xianping,ZHANG Jian,et al.Features and geologic significances of the top Sinian karst landform before the Cambrian deposition in the Sichuan Basin[J].Natural Gas Industry,2014,34(3):38-43.
[7] 李智武,冉波,肖斌,等.四川盆地北缘震旦纪—早寒武世隆—坳格局及其油气勘探意义[J].地学前缘2019,26(1):59-85.LI Zhiwu,RAN Bo,XIAO Bin,et al.Ediacaran to Early Cambrian uplift-depression framework along the northern margin of the Sichuan Basin,Central China and its implications for hydrocarbon exploration[J].Earth Science Frontiers,2019,26(1):59-85.
[8] KUNIMITSU Y,TOGO T,SAMPEI Y,et al.Organic compositions of the embryo-bearing lowermost Cambrian Kuanchuanpu Formation on the northern Yangtze Platform,China[J].Palaeogeography,Palaeoclimatology,Palaeoecology,2009,280(3/4):499-506.
[9] CHEN Daizhao,WANG Jianguo,QING Hairuo,et al.Hydrothermal venting activities in the Early Cambrian,South China:petrological,geochronological and stable isotopic constraints[J].Chemical Geology,2009,258(3/4):168-181.
[10] CHEN Daizhao,ZHOU Xiqiang,FU Yong,et al.New U-Pb zircon ages of the Ediacaran-Cambrian boundary strata in South China[J].Terra Nova,2015,27(1):62-68.
[11] CHEN Zhonghong,SIMONEIT B R T,WANG T G,et al.Biomarker signatures of Sinian bitumens in the Moxi-Gaoshiti bulge of Sichuan Basin,China:Geological significance for paleo-oil reservoirs[J].Precambrian Research,2017,296:1-19.
[12] CHEN Lan,ZHONG Hong,HU RUIZHONG,et al.Paleoceanographic indicators for Early Cambrian black shales from the Yangtze Platform,South China:evidence from biomarkers and carbon isotopes[J].Acta Geologica Sinica (English Edition),2012,86(5):1143-1153.
[13] WU Chenjun,TUO Jincai,ZHANG Mingfeng,et al.Sedimentary and residual gas geochemical characteristics of the Lower Cambrian organic-rich shales in Southeastern Chongqing,China[J].Marine and Petroleum Geology,2016,75:140-150.
[14] HAN Shanchu,HU Kai,CAO Jian,et al.Origin of Early Cambrian black-shale-hosted barite deposits in South China:mineralogical and geochemical studies[J].Journal of Asian Earth Sciences,2015,106:79-94.
[15] PETERS K E,WALTERS C C,MOLDOWAN J M.The biomarker guide[M].2nd ed.Cambridge:Cambridge University Press,2005:490.
[16] CHEN Lan,XU Guiwen,DA Xuejuan,et al.Biomarkers of Middle to Late Jurassic marine sediments from a canonical section:new records from the Yanshiping area,northern Tibet[J].Marine and Petroleum Geology,2014,51:256-267.
[17] 任拥军,杨景楠,邱隆伟,等.大王北洼陷烃源岩有机地球化学特征[J].高校地质学报,2010,16(1):63-72.REN Yongjun,YANG Jingnan,QIU Longwei,et al.Organic geochemical characteristics of source rocks in Dawangbei Subsag[J].Geological Journal of China Universities,2010,16(1):63-72.
[18] 张水昌,卢松年.海洋古细菌分子化石[J].地球科学(中国地质大学学报),1993,18(4):381-392.ZHANG Shuichang,LU Songnian.Molecular fossils derived from marine palaeobacteria[J].Earth Science(Journal of China University of Geosciences),1993,18(4):381-392.
[19] BIRD C W,LYNCH J M,PIRT F J,et al.Steroids and squalene in methylococcus capsulatus grown on methane[J].Nature,1971,230(5294):473-474.
[20] HUANG Difan,ZHANG Dajiang,LI Jinchao.The origin of 4-methyl steranes and pregnanes from Tertiary strata in the Qaidam Basin,China[J].Organic Geochemistry,1994,22(2):343-348.
[21] SCHRENK M O,KELLEY D S,DELANEY J R,et al.Incidence and diversity of microorganisms within the walls of an active deep-sea sulfide chimney[J].Applied and Environmental Microbiology,2003,69(6):3580-3592.
[22] SUZUKI Y,INAGAKI F,TAKAI K,et al.Microbial diversity in inactive chimney structures from deep-sea hydrothermal systems[J].Microbial Ecology,2004,47(2):186-196.
[23] XU Lingang,LEHMANN B,MAO Jingwen,et al.Strontium,sulfur,carbon,and oxygen isotope geochemistry of the Early Cambrian strata-bound barite and witherite deposits of the Qinling-Daba region,northern margin of the Yangtze Craton,China[J].Economic Geology,2016,111(3):695-718.
[24] 刘家军,吕志成,吴胜华,等.南秦岭大巴山大型钡成矿带中锶同位素组成及其成因意义[J].地学前缘,2014,21(5):23-30.LIU Jiajun,LV Zhicheng,WU Shenghua,et al.Strontium isotopic composition and its genetic significance of the Dabashan large barium metallogenic belt in southern Qinling Mountains[J].Earth Science Frontiers,2014,21(5):23-30.
[25] 刘家军,柳振江,杨艳,等.南秦岭大型钡成矿带有机地球化学特征与生物标示物研究[J].矿物岩石,2007,27(3):39-48.LIU Jiajun,LIU Zhenjiang,YANG Yan,et al.Research on the organic geochemistry and biomarkers of the large-scale barium metallogenic belt in the southern Qinling Mountains,China[J].Journal of Mineralogy and Petrology,2007,27(3):39-48.
[26] LI Jinxi,LI Zhiwu,LIU Shugen,et al.Kinematics of the Chengkou Fault in the South Qinling Orogen,Central China[J].Journal of Structural Geology,2018,114:64-75.
[27] DIDYK B M,SIMONEIT B R T,BRASSEL S C,et al.Organic geochemical indicators of palaeoenvironmental conditions of sedimentation[J].Nature,1978,272(5650):216-222.
[28] 张立平,黄第藩,廖志勤.伽马蜡烷:水体分层的地球化学标志[J].沉积学报,1999,17(1):136-140.ZHANG Liping,HUANG Difan,LIAO Zhiqin.Gammacerane:geochemical indicator of water column stratification[J].Acta Sedimentologica Sinica,1999,17(1):136-140.
[29] BOETIUS A,RAVENSCHLAG K,SCHUBERT C J,et al.A marine microbial consortium apparently mediating anaerobic oxidation of methane[J].Nature,2000,407(6804):623-626.
[30] VESTER F,INGVORSEN K.Improved most-probable-number method to detect sulfate-reducing bacteria with natural media and a radiotracer[J].Applied and Environment Microbiology,1998,64(5):1700-1707.
[31] LóPEZ-GARCIA P,DUPERRON S,PHILIPPOT P,et al.Bacterial diversity in hydrothermal sediment and epsilonproteobacterial dominance in experimental microcolonizers at the Mid-Atlantic ridge[J].Environmental Microbiology,2003,5(10):961-976.
[32] PIPER D Z.Marine chemistry of the Permian Phosphoria Formation and basin,Southeast Idaho[J].Economic Geology,2001,96(3):599-620.
[33] 蔡朝阳,何崭飞,胡宝兰.甲烷氧化菌分类及代谢途径研究进展[J].浙江大学学报(农业与生命科学版),2016,42(3):273-281.CAI Zhaoyang,HE Zhanfei,HU Baolan.Progress in the classification and mechanism of methane-oxidizing bacteria[J].Journal of Zhejiang University (Agriculture & Life Sciences),2016,42(3):273-281.
[34] HOEHLER T M,ALPERIN M J,ALBERT D B,et al.Field and laboratory studies of methane oxidation in an anoxic marine sediment:evidence for a methanogen-sulfate reducer consortium[J].Global Biogeochemical Cycles,1994,8(4):451-463.
[35] GUO Qingjun,SHIELDS G A,LIU Congqiang,et al.Trace element chemostratigraphy of two Ediacaran-Cambrian successions in South China:implications for organosedimentary metal enrichment and silicification in the Early Cambrian[J].Palaeogeography,Palaeoclimatology,Palaeoecology,2007,254(1/2):194-216.
[2] LIU Shugen,DENG Bin,JANSA L,et al.The Early Cambrian Mianyang-Changning intracratonic sag and its control on petroleum accumulation in the Sichuan Basin,China[J].Geofluids,2017,2017:6740892.
[3] 刘树根,孙玮,罗志立,等.兴凯地裂运动与四川盆地下组合油气勘探[J].成都理工大学学报(自然科学版),2013,40(5):511-520.LIU Shugen,SUN Wei,LUO Zhili,et al.Xingkai taphrogenesis and petroleum exploration from Upper Sinian to Cambrian Strata in Sichuan Basin,China[J].Journal of Chengdu University of Technology (Science & Technology Edition),2013,40(5):511-520.
[4] ZOU Caineng,DU Jinhu,XU Chunchun,et al.Formation,distribution,resource potential,and discovery of Sinian-Cambrian Giant Gas Field,Sichuan Basin,SW China[J].Petroleum Exploration and Development Online,2014,41(3):306-325.
[5] 周慧,李伟,张宝民,等.四川盆地震旦纪末期—寒武纪早期台盆的形成与演化[J].石油学报,2015,36(3):310-323.ZHOU Hui,LI Wei,ZHANG Baomin,et al.Formation and evolution of Upper Sinian to Lower Cambrian intraplatformal basin in Sichuan Basin[J].Acta Petrolei Sinica,2015,36(3):310-323.
[6] 杨雨,黄先平,张健,等.四川盆地寒武系沉积前震旦系顶界岩溶地貌特征及其地质意义[J].天然气工业,2014,34(3):38-43.YANG Yu,HUANG Xianping,ZHANG Jian,et al.Features and geologic significances of the top Sinian karst landform before the Cambrian deposition in the Sichuan Basin[J].Natural Gas Industry,2014,34(3):38-43.
[7] 李智武,冉波,肖斌,等.四川盆地北缘震旦纪—早寒武世隆—坳格局及其油气勘探意义[J].地学前缘2019,26(1):59-85.LI Zhiwu,RAN Bo,XIAO Bin,et al.Ediacaran to Early Cambrian uplift-depression framework along the northern margin of the Sichuan Basin,Central China and its implications for hydrocarbon exploration[J].Earth Science Frontiers,2019,26(1):59-85.
[8] KUNIMITSU Y,TOGO T,SAMPEI Y,et al.Organic compositions of the embryo-bearing lowermost Cambrian Kuanchuanpu Formation on the northern Yangtze Platform,China[J].Palaeogeography,Palaeoclimatology,Palaeoecology,2009,280(3/4):499-506.
[9] CHEN Daizhao,WANG Jianguo,QING Hairuo,et al.Hydrothermal venting activities in the Early Cambrian,South China:petrological,geochronological and stable isotopic constraints[J].Chemical Geology,2009,258(3/4):168-181.
[10] CHEN Daizhao,ZHOU Xiqiang,FU Yong,et al.New U-Pb zircon ages of the Ediacaran-Cambrian boundary strata in South China[J].Terra Nova,2015,27(1):62-68.
[11] CHEN Zhonghong,SIMONEIT B R T,WANG T G,et al.Biomarker signatures of Sinian bitumens in the Moxi-Gaoshiti bulge of Sichuan Basin,China:Geological significance for paleo-oil reservoirs[J].Precambrian Research,2017,296:1-19.
[12] CHEN Lan,ZHONG Hong,HU RUIZHONG,et al.Paleoceanographic indicators for Early Cambrian black shales from the Yangtze Platform,South China:evidence from biomarkers and carbon isotopes[J].Acta Geologica Sinica (English Edition),2012,86(5):1143-1153.
[13] WU Chenjun,TUO Jincai,ZHANG Mingfeng,et al.Sedimentary and residual gas geochemical characteristics of the Lower Cambrian organic-rich shales in Southeastern Chongqing,China[J].Marine and Petroleum Geology,2016,75:140-150.
[14] HAN Shanchu,HU Kai,CAO Jian,et al.Origin of Early Cambrian black-shale-hosted barite deposits in South China:mineralogical and geochemical studies[J].Journal of Asian Earth Sciences,2015,106:79-94.
[15] PETERS K E,WALTERS C C,MOLDOWAN J M.The biomarker guide[M].2nd ed.Cambridge:Cambridge University Press,2005:490.
[16] CHEN Lan,XU Guiwen,DA Xuejuan,et al.Biomarkers of Middle to Late Jurassic marine sediments from a canonical section:new records from the Yanshiping area,northern Tibet[J].Marine and Petroleum Geology,2014,51:256-267.
[17] 任拥军,杨景楠,邱隆伟,等.大王北洼陷烃源岩有机地球化学特征[J].高校地质学报,2010,16(1):63-72.REN Yongjun,YANG Jingnan,QIU Longwei,et al.Organic geochemical characteristics of source rocks in Dawangbei Subsag[J].Geological Journal of China Universities,2010,16(1):63-72.
[18] 张水昌,卢松年.海洋古细菌分子化石[J].地球科学(中国地质大学学报),1993,18(4):381-392.ZHANG Shuichang,LU Songnian.Molecular fossils derived from marine palaeobacteria[J].Earth Science(Journal of China University of Geosciences),1993,18(4):381-392.
[19] BIRD C W,LYNCH J M,PIRT F J,et al.Steroids and squalene in methylococcus capsulatus grown on methane[J].Nature,1971,230(5294):473-474.
[20] HUANG Difan,ZHANG Dajiang,LI Jinchao.The origin of 4-methyl steranes and pregnanes from Tertiary strata in the Qaidam Basin,China[J].Organic Geochemistry,1994,22(2):343-348.
[21] SCHRENK M O,KELLEY D S,DELANEY J R,et al.Incidence and diversity of microorganisms within the walls of an active deep-sea sulfide chimney[J].Applied and Environmental Microbiology,2003,69(6):3580-3592.
[22] SUZUKI Y,INAGAKI F,TAKAI K,et al.Microbial diversity in inactive chimney structures from deep-sea hydrothermal systems[J].Microbial Ecology,2004,47(2):186-196.
[23] XU Lingang,LEHMANN B,MAO Jingwen,et al.Strontium,sulfur,carbon,and oxygen isotope geochemistry of the Early Cambrian strata-bound barite and witherite deposits of the Qinling-Daba region,northern margin of the Yangtze Craton,China[J].Economic Geology,2016,111(3):695-718.
[24] 刘家军,吕志成,吴胜华,等.南秦岭大巴山大型钡成矿带中锶同位素组成及其成因意义[J].地学前缘,2014,21(5):23-30.LIU Jiajun,LV Zhicheng,WU Shenghua,et al.Strontium isotopic composition and its genetic significance of the Dabashan large barium metallogenic belt in southern Qinling Mountains[J].Earth Science Frontiers,2014,21(5):23-30.
[25] 刘家军,柳振江,杨艳,等.南秦岭大型钡成矿带有机地球化学特征与生物标示物研究[J].矿物岩石,2007,27(3):39-48.LIU Jiajun,LIU Zhenjiang,YANG Yan,et al.Research on the organic geochemistry and biomarkers of the large-scale barium metallogenic belt in the southern Qinling Mountains,China[J].Journal of Mineralogy and Petrology,2007,27(3):39-48.
[26] LI Jinxi,LI Zhiwu,LIU Shugen,et al.Kinematics of the Chengkou Fault in the South Qinling Orogen,Central China[J].Journal of Structural Geology,2018,114:64-75.
[27] DIDYK B M,SIMONEIT B R T,BRASSEL S C,et al.Organic geochemical indicators of palaeoenvironmental conditions of sedimentation[J].Nature,1978,272(5650):216-222.
[28] 张立平,黄第藩,廖志勤.伽马蜡烷:水体分层的地球化学标志[J].沉积学报,1999,17(1):136-140.ZHANG Liping,HUANG Difan,LIAO Zhiqin.Gammacerane:geochemical indicator of water column stratification[J].Acta Sedimentologica Sinica,1999,17(1):136-140.
[29] BOETIUS A,RAVENSCHLAG K,SCHUBERT C J,et al.A marine microbial consortium apparently mediating anaerobic oxidation of methane[J].Nature,2000,407(6804):623-626.
[30] VESTER F,INGVORSEN K.Improved most-probable-number method to detect sulfate-reducing bacteria with natural media and a radiotracer[J].Applied and Environment Microbiology,1998,64(5):1700-1707.
[31] LóPEZ-GARCIA P,DUPERRON S,PHILIPPOT P,et al.Bacterial diversity in hydrothermal sediment and epsilonproteobacterial dominance in experimental microcolonizers at the Mid-Atlantic ridge[J].Environmental Microbiology,2003,5(10):961-976.
[32] PIPER D Z.Marine chemistry of the Permian Phosphoria Formation and basin,Southeast Idaho[J].Economic Geology,2001,96(3):599-620.
[33] 蔡朝阳,何崭飞,胡宝兰.甲烷氧化菌分类及代谢途径研究进展[J].浙江大学学报(农业与生命科学版),2016,42(3):273-281.CAI Zhaoyang,HE Zhanfei,HU Baolan.Progress in the classification and mechanism of methane-oxidizing bacteria[J].Journal of Zhejiang University (Agriculture & Life Sciences),2016,42(3):273-281.
[34] HOEHLER T M,ALPERIN M J,ALBERT D B,et al.Field and laboratory studies of methane oxidation in an anoxic marine sediment:evidence for a methanogen-sulfate reducer consortium[J].Global Biogeochemical Cycles,1994,8(4):451-463.
[35] GUO Qingjun,SHIELDS G A,LIU Congqiang,et al.Trace element chemostratigraphy of two Ediacaran-Cambrian successions in South China:implications for organosedimentary metal enrichment and silicification in the Early Cambrian[J].Palaeogeography,Palaeoclimatology,Palaeoecology,2007,254(1/2):194-216.