Lacustrine microbial dolomite of the Middle Permian Lucaogou Formation in rümqi，Xinjiang
Lei Chuan1，2 Li Hong1 Yang Rui1 Cheng Jun3
1 State Key Laboratory of Continental Dynamics，Department of Geology，Northwest University，Xi′an 710069，Shaanxi;2 Lanzhou Center for Oil and Gas Resources, Institute of Geology and Geophysics,Chinese Academy of Sciences，Lanzhou 730000,Gansu;3 Shaanxi Institute of Geological Survey，Xianyang 712000，Shaanxi
The dark-gray，middle to thin-bedded dolostone，limestone，siltstone，and gray or black shale and mudstone，deposited in shallow to open lake settings, are mainly developed in the Middle Permian Lucaogou Formation in southern Hongyanchi section of rümqi in Xinjiang. Dolostone which is rich in organic matter is mainly composed of dolomite and ankerite with small amount of calcite and Mg-calcite.The dolomite ranges from 3 to 10μm in crystal sizes and shows homogeneously dark-red luminescence.Micromorphologies of the dolomite vary from microspherules(5～8μm in diameter)，clusters(about 2μm long)，to anhedral dolomite under the SEM.Microspherules have microlaminae structure called “growth coating” which consists of numerous nanoscale particles in the 60000 times enlarged SEM photomicrographs.Anhedral dolomite which is mainly composed of massive particles(about 0.25μm)in 40000 times enlarged SEM photomicrographs shows the features of microbial mineralization.The above morphologies of dolomite are highly similar to the typical modern microbial dolomite in experiment-culture and natural environments.The δ13CPDB value of dolomite ranges from 1.8‰ to 13.8‰，and δ18OPDB value ranges from-12.1‰ to-4.1‰.The higher δ13CPDB value may be the result of isotope fractionation led by methane-producing bacteria.The characteristics of micromorphologies and stable isotope indicate that the precipitation of the Middle Permian dolomite had close relation to activities of anaerobic organisms.
About author: Lei Chuan，born in 1988，is a master candidate of Lanzhou Center for Oil and Gas Resources，Institute of Geology and Geophysics，Chinese Academy of Sciences.E-mail: leichuan1988@163.com. About the corresponding author Li Hong，working at Department of Geology，Northwest University，is mainly engaged in sedimentology and reservoir geology.E-mail: lihong2008@nwu.edu.cn.
Cite this article:
Lei Chuan,Li Hong,Yang Rui et al. Lacustrine microbial dolomite of the Middle Permian Lucaogou Formation in rümqi，Xinjiang[J]. JOURNAL OF PALAEOGEOGRAPHY, 2012, 14(6): 767-776.
Lei Chuan,Li Hong,Yang Rui et al. Lacustrine microbial dolomite of the Middle Permian Lucaogou Formation in rümqi，Xinjiang[J]. JOPC, 2012, 14(6): 767-776.
黄志诚，杨守业，陈智娜.1996.原生白云石与交代白云石的矿物学对比研究［J］.中国科学（D辑），26(6):544-550. 李波，颜佳新，刘喜停，等.2010.白云岩有机成因模式：机制、进展与意义［J］.古地理学报，12（6）:699-710. 于炳松，董海良，蒋宏忱，等.2007.青海湖底沉积物中球状白云石集合体的发现及其地质意义［J］.现代地质，21(1):66-70. 张晓宝，王志勇，徐永昌.2000.特殊碳同位素组成白云岩的发现及其意义［J］.沉积学报，18(3):449-452. Alperin M J，Reeburgh W S，Whiticar M J.1988.Carbon and hydrogen isotope fractionation resulting from anaerobic methane oxidation［J］.Global Biogeochemical Cycles，2(3):279-288. Baertschi P.1976.Absolute 18O content of standard mean ocean water［J］.Earth and Planetary Science Letters，31:341-344. Boetius A，Ravenschlag K，Schubert C J， et al.2000.A marine microbial consortium apparently mediating anaerobic oxidation of methane［J］.Nature，407(6804):623-626. Ciftcioglu N，McKay D S，Mathew G， et al.2006.Nanobacteria: Fact or fiction？characteristics，detection，and medical importance of novel self-replicating，calcifying nanoparticles［J］.Journal of Investigative Medicine，54:385-394. Compton J S.1988.Degree of supersaturation and precipitation of organogenic dolomite［J］.Geology，16:318-321. Deng S C，Dong H L，Guo L， et al.2010.Microbial dolomite precipitation using sulfate reducing and halophilic bacteria：Results from Qinghai Lake，Tibetan Plateau，NW China［J］.Chemical Geology，278:151-159. Fernndez-Diaz L，Astilleros J M，Pina C M.2006.The morphology of calcite crystals grown in a porous medium doped with divalent cations［J］.Chemical Geology，225:314-321. Folk R L.1993.SEM imaging of bacteria and nannobacteria in carbonate sediments and rocks［J］.Journal of Sedimentary Petrology，63:990-999. Games L M，Hayes J M，Gunsalus R P.1978.Methane producing bacteria: Natural fractionations of the stable carbon isotopes［J］.Geochimica et Cosmochimica Acta，42:1295-1297. García del Cura M A，Calvo J P，Ordóez S， et al.2001.Petrographic and geochemical evidence for the formation of primary，bacterially induced lacustrine dolomite: La Roda ‘white earth’(Pliocene，central Spain)［J］.Sedimentology，48: 897-915. Jones B.2010.The preferential association of dolomite with microbes in stalactites from Cayman Brac，British West Indies［J］.Sedimentary Geology，226: 94-109. Kenward P A，Goldstein R H，Gonzlez L A， et al. 2009.Precipitation of low-temperature dolomite from an anaerobic microbial consortium: The role of methanogenic Archaea［J］.Geobiology，7(5):556-565. Korte C，Jasper T，Kozur H W， et al.2005.δ18O and δ13C of Permian brachiopods: A record of seawater evolution and continental glaciation［J］.Palaeogeography，Palaeoclimatology，Palaeoecology，224:333-351. Magaritz M，Stemmerik L.1989.Oscillation of carbon and oxygen isotope compositions of carbonate rocks between evaporative and open marine environments，Upper Permian of East Greenland［J］.Earth and Planetary Science Letters，93(2):233-240. Maniloff J.1997.Nannobacteria: Size limits and evidence［J］.Science，276(5320):1776. Mazzullo S J.2000.Organogenic dolomitization in peritidal to deep-sea sediments［J］.Journal of Sedimentary Research，70(1):10-23. Mazzullo S J，Bischoff W D，Teal C S.1995.Holocene shallow subtidal dolomitization by near normal seawater，northern Belize［J］.Geology，23: 341-344. Meister P，Mckenzie J A，Vasconcelos C， et al.2007.Dolomite formation in the dynamic deep biosphere: Results from the Peru Margin［J］.Sedimentology，54: 1007-1031. Meister P，Gutjahr M，Frank M， et al.2011.Dolomite formation within the methanogenic zone induced by tectonically driven fluids in the Peru accretionary prism［J］.Geology，39: 563-566. Perri E，Tucker M.2007.Bacterial fossils and microbial dolomite in Triassic stromatolites［J］.Geology，35(3):207-210. Roberts J A，Bennett P C，Gonzlez L A， et al. 2004.Microbial precipitation of dolomite in methanogenic groundwater［J］.Geology，32(4):277-280. Snchez-Romn M，McKenzie J A，de Luca Rebello Wagener A， et al.2009a.Presence of sulfate does not inhibit low-temperature dolomite precipitation［J］.Earth and Planetary Science Letters，285:131-139. Snchez-Romn M，Romanek C S，Fernndez-Remolar D C， et al.2011.Aerobic biomineralization of Mg-rich carbonates: Implications for natural environments［J］.Chemical Geology，281:143-150. Snchez-Romn M，Vasconcelos C，Schmid T， et al.2008.Aerobic microbial dolomite at the nanometer scale: Implications for the geologic record［J］.Geology，36(11):879-882. Snchez-Romn M，Vasconcelos C，Warthmann R， et al. 2009b.Microbial dolomite precipitation under aerobic conditions: Results from Brejo do Espinho Lagoon(Brazil)and culture experiments［C］.In: Swart P K，Eberli G P，McKenzie J A(eds).Perspectives in Sedimentary Geology: A Tribute to the Career of Robert Nathan Ginsburg，IAS Special Publication，41:167-178. Tracy S L，Franois C J P，Jennings H M.1998a. The growth of calcite spherulites from solution I.Experimental design techniques［J］. Journal of Crystal Growth，193:374-381. Tracy S L，Franois C J P，Jennings H M.1998b. The growth of calcite spherulites from solution Ⅱ.Kinetics of formation ［J］. Journal of Crystal Growth，193: 381-388. van Lith Y，Warthmann R，Vasconcelos C，et al.2003.Microbial fossilization in carbonate sediments: A result of the bacterial surface involvement in dolomite precipitation［J］.Sedimentology，50:237-245. Vasconcelos C，McKenzie J A.1997.Microbial mediation of modern dolomite precipitation and diagenesis under anoxic conditions(Lagoa Vermelha，Riode Janeiro，Brazil)［J］.Journal of Sedimentary Research，67(3):378-390. Vasconcelos C，McKenzie J A，Bernasconi S， et al.1995.Microbial mediation as a possible mechanism for natural dolomite formation at low temperature［J］.Nature，377(6546):220-222. Wacey D.2007.A stable isotope study of microbial dolomite formation in the Coorong Region，South Australia［J］.Chemical Geology，244：155-174. Warthmann R，van Lith Y，Vasconcelos C， et al.2000.Bacterially induced dolomite precipitation in anoxic culture experiments［J］.Geology，28(12):1091-1094. Warthmann R，Vasconcelos C，Sass H， et al.2005.Desulfovibrio brasiliensis sp.nov.，a moderate halophilic sulfate-reducing bacterium from Lagoa Vermelha(Brazil)mediating dolomite formation［J］.Extremephiles，9: 255-261. Whiticar M J.1999.Carbon and hydrogen isotope systematics of bacterial formation and oxidation of methane［J］.Chemical Geology，161:291-314. William D R，Silverman S R.1965.Carbon isotope fractionation in bacterial production of methane［J］.Science，130:1658-1659. Wright D T.1999.The role of sulphate-reducing bacteria and cyanobacteria in dolomite formation in distal ephemeral lakes of the Coorong region，South Australia［J］.Sedimentary Geology，126:147-157. Wright V P.1992.A revised classification of limestones［J］.Sedimentary Geology，76: 177-185.
