Carbon Isotopes and the Stratigraphical Implication of the Late Permian Carbonates in Central Guangxi

Shao Longyi; Jones T P

The carbon isotope compositions of the Late Permian carbonate rocks in central Guangxi show a sharp decrease at the boundary between Wujiapingian and Changxingian(W/C) stages.The limestone samples of the Wujiapingian stage have the δ¹³C values higher than 3.2‰,whereas the Changingian samples have the δ¹³C values lower than 3.2‰.This negative shift is suggested to be used to distingush the Wujiapingian and Changxingian stages.The carbon isotope depletion at the W/C boundary is believed to be related to the termination of the coal accumulation in large areas such as the India,eastern Australia,and South Africa but not southern China.The cessation of the coal accumulation and the oxidation of the previously buried coals as a result of the tectonic uplift may release¹²C rich CO₂ into the atmosphere which further leads to the decrease of the δ¹³C values in ocean water and the marine carbonate rocks.

Carbon Isotopes and the Stratigraphical Implication of the Late Permian Carbonates in Central Guangxi

1. China University of Mining and Technology,Beijing 100083;

Department of Earth Sciences,Cardiff University, Cardiff,CFI 3YE,UK

Received Date: 1997-11-18

Rev Recd Date: 1998-04-13

Publish Date: 1999-03-10

Key words:

Abstract: The carbon isotope compositions of the Late Permian carbonate rocks in central Guangxi show a sharp decrease at the boundary between Wujiapingian and Changxingian(W/C) stages.The limestone samples of the Wujiapingian stage have the δ¹³C values higher than 3.2‰,whereas the Changingian samples have the δ¹³C values lower than 3.2‰.This negative shift is suggested to be used to distingush the Wujiapingian and Changxingian stages.The carbon isotope depletion at the W/C boundary is believed to be related to the termination of the coal accumulation in large areas such as the India,eastern Australia,and South Africa but not southern China.The cessation of the coal accumulation and the oxidation of the previously buried coals as a result of the tectonic uplift may release¹²C rich CO₂ into the atmosphere which further leads to the decrease of the δ¹³C values in ocean water and the marine carbonate rocks.

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[1]

1 Holsr W T,Wagariz M,Clark D L.Carbon isotope stratigraphic correlations in the Late permian.Amer.J.Sci.,1986,286:390～402

2 李子舜.古生代—中生代之交的生物绝灭的地质事件.地质学报，1986，(1)：1～15

3 Magaritz M，Bar R，Baud A. Holser W T.The carbon-isotope shift at the Permian-Triassicboundary in the southern Alps is gradual. Nature,1988，331:337～339

4 陈锦石.碳同位素地层学研究.矿物岩石地球化学通讯.1990(2)：113～114

5 Chen J,Chu X, Shao M, Zhong H.Carbon isotope study of the Permian-Triassic boundary sequences in China. Chemical Geology(Isotope Geoscience Section)，1991, 89：239～251

6 Baud A, Magaritz M, Holser W T.Permian-Triassic of the Tethys:Carbon isotope studies.Geologische Rundschau，1989,78:649～677

7 黄思静.上扬子二叠系-三叠系初海相碳酸盐岩组成与生物绝灭事件.地球化学，1994，(1)：60～67

8 张鹏飞，邵龙义.广西合山地区合山组沉积相带和沉积模式.沉积学报，1990，8(4)：13～21

9 沈树忠，范炳恒，邵龙义，傅肃雷.黔桂晚二叠世煤层的生物地层对比研究.煤田地质与勘探，1995，23(6)：1～5

10 Shao L,Zhang P.Late Permian coal-bearing carbonate sequences in central Guangxi,southern China:Depositional environments and coal accumulation.Scientia Geologica Sinica (Overseas Edition),1994,3: 221～230

11 邵龙义，窦建伟，张鹏飞.西南地区晚二叠世氧、碳稳定同位素的古地理意义.地球化学，1996，25(6)：575～581

12 McKenzie E T.Sedimentary cycling and the evolution of sea water.In:Riley J P,et al，eds.Chemical Oceanography(2nd edition)，1975.

13 廖卓庭.广西来宾合山晚二叠世硅化腕足类及其古生态特征.见：中国各系界线地层及古生物-二叠系与三叠系界线(一).南京：南京大学出版社，1987.81～125

14 Kump L R,Garrels R M,Modeling atmospheric O₂ in the global sedimentary redox cycle.Amer.J. Sci.,1986,286:337～360

15 Veevers J J,Conagham P J,Shaw S E.Turning point in Pangean environmental history at the Permian-Triassic boundary, In：Klein G D,ed. Pangea: Paleoclimate, Tectonics,and Sedimentation during Accretion,Zenith,and breakup of a supercontinent. Boulder, Colorado,Gerlogical Society of America Special Paper，1994,288:187～196

16 Faure K,de Wit M J,Willis J P.Late Permian global coal hiatus linked to ¹³ C-depleted CO₂ flux into the atmosphere during the final consolidation of Pangea.Geology,1995,23:507～510

17 Taylor J C M.Late Permian-Zechstein.In: Glennie K W,ed.Introduction to the PetroleumGeology of the North Sea(second edition). Blackwell Scientific Publications,1986.87 ～111

18 韩德馨，杨起.中国煤田地质学(下册).北京：煤炭工业出版社.1980.1～415

19 Harland W B,Armstrong R L,Cox A V,Craig L E,Smith A G,Smith D G.A geologic time scale.Cambridge,United Kingdom,Cambridge University Press,1990.263

Carbon Isotopes and the Stratigraphical Implication of the Late Permian Carbonates in Central Guangxi

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