Characteristics of carbon and oxygen isotopes of the Ordovician carbonate rocks in Ordos and their implication

doi:10.7605/gdlxb.2012.01.010

Abstract

Abstract: The Ordos has gigantically thick Paleozoic marine strata.The carbon and oxygen isotopes of the Ordovician carbonate rocks in the Ordos are less modified by post-depositional diagenesis，and thus provide helpful insights into the original ocean.The δ¹³C values of the Ordovician carbonate rocks in the Ordos range from -7.30‰ to 2.26‰ with a mean value of -0.30‰ and the δ¹⁸O varies between -13.14‰ and -1.94‰，averaging at -6.38‰，which indicate the carbon and oxygen isotopes of the Ordovician in the Ordos are comparable to those of the global Ordovician.Spatially，the δ¹³C shows a decreasing trend，indicating shoaling in water-depth from the western margin of the Ordos，to the southern margin and then to the eastern margin.Temporally，the δ¹³C gradually increases，showing that sea level rose from the Early to the Late Ordovician，with a significant positive excursion between the Middle and Late Ordovician that is indicated by increase in mean δ¹³C value from -0.36‰ in the Majiagou Formation to 0.15‰ in the Pingliang Formation and then to 0.68‰ in the Beiguoshan Formation.Sea level change suggested by carbon isotope distribution is consistent with the evolution of sedimentary facies.The positive excursion of carbon isotopes in the Middle and Late Ordovician in the Ordos indicates relative high productivity and organic carbon burial，which is of important petroleum geological significance，reflecting the Pingliang Formation，Wulalike Formation and Beiguoshan Formation in the southwestern margin as the most important and efficient hydrocarbon source rocks of the Lower Paleozoic in the Ordos.

Key words: carbon and oxygen isotopes, paleoenvironment, petroleum geology, Ordovician, Ordos

摘要： 鄂尔多斯古生代海相地层沉积厚度巨大。鄂尔多斯奥陶系碳酸盐岩的碳氧同位素组成受后期成岩作用影响较小，基本保留了原始海洋的同位素组成： δ¹³C值分布于-7.30‰～2.26‰之间，均值-0.30‰；δ¹⁸O值分布于-13.14‰～-1.94‰之间，均值-6.38‰，碳氧同位素组成与全球基本一致。区域上，鄂尔多斯西缘具有相对较高的δ¹³C值，南缘次之，而东缘最低。纵向上，碳同位素组成逐渐增重，并在中晚奥陶世发生明显的正向偏移，δ¹³C均值由马家沟组的-0.36‰增加到平凉组的0.15‰，至背锅山组增加至0.68‰。碳同位素的区域分布差异表明鄂尔多斯西缘水体相对较深，南缘次之，东缘相对较浅，由早奥陶世至晚奥陶世水体逐渐加深，碳同位素组成反映的海平面变化趋势与沉积相演化一致。鄂尔多斯西南缘中晚奥陶世碳同位素组成的正向偏移，标志着较高的生产力和有机碳埋藏率，具有重要的石油地质学意义，西南缘的平凉组/乌拉力克组和背锅山组是下古生界最重要和有效的烃源岩层。

关键词: 碳氧同位素, 古环境, 石油地质, 奥陶系, 鄂尔多斯

CLC Number:

P597+.2

Chen Qiang, Zhang Huiyuan, Li Wenhou, Hao Songli, Liu Zhuo. Characteristics of carbon and oxygen isotopes of the Ordovician carbonate rocks in Ordos and their implication[J]. JOURNAL OF PALAEOGEOGRAPHY, 2012, 14(1): 117-124.

陈强, 张慧元, 李文厚, 郝松立, 刘卓. 鄂尔多斯奥陶系碳酸盐岩碳氧同位素特征及其意义^*[J]. 古地理学报, 2012, 14(1): 117-124.

/ / Recommend / Download Citations

URL: http://www.gdlxb.cn/EN/10.7605/gdlxb.2012.01.010

http://www.gdlxb.cn/EN/Y2012/V14/I1/117

References

安太庠，郑昭昌.1990.鄂尔多斯盆地周缘的牙形石［M］.北京：科学出版社，1-201.
包洪平，杨承运.2000.鄂尔多斯东部奥陶系马家沟组微相分析［J］.古地理学报，2（1）:33-42.
鲍志东，李儒峰，冯增昭.1999.鄂尔多斯盆地东西部奥陶系对比再研究［J］.地质论评，45（4）:375-382.
陈孟晋，宁宁，胡国艺，等.2007.鄂尔多斯盆地西部平凉组烃源岩特征及其影响因素［J］.科学通报，52(S1):78-85.
陈孟晋，汪泽成，孙粉锦.2006.鄂尔多斯西缘前陆盆地油气地质［M］.北京：石油工业出版社，1-229.
冯增昭，鲍志东，康祺发，等.1999a.鄂尔多斯早古生代古构造［J］.古地理学报，1（2）:84-91.
冯增昭，鲍志东，康祺发，等.1999b.鄂尔多斯奥陶纪古构造［J］.古地理学报，1（3）:83-94.
冯增昭，鲍志东，张永生，等.1998.鄂尔多斯奥陶纪地层岩石岩相古地理［M］.北京：地质出版社，1-144.
冯增昭，陈继新，张吉森.1991.鄂尔多斯地区早古生代岩相古地理［M］.北京：地质出版社，1-190.
付金华，郑聪斌.2001.鄂尔多斯盆地奥陶纪华北海和祁连海演变及岩相古地理特征［J］.古地理学报，3（4）:25-34.
彭冰霞，王岳军，范蔚茗，等.2006.贵州乐康剖面茅口阶—吴家坪阶碳同位素组成变化及峨眉山大火成岩省的响应［J］.地球化学，35(2):126-132.
腾格尔，刘文汇，徐永昌，等.2004.海相沉积有机质的碳同位素记录及其环境意义——以鄂尔多斯盆地为例［J］.石油勘探与开发，31(5):11-16.
腾格尔，刘文汇，徐永昌，等.2005.海相地层无机参数与烃源岩发育环境的相关研究——以鄂尔多斯盆地为例［J］.石油与天然气地质，26(4):411-421.
腾格尔，刘文汇，徐永昌，等.2006.高演化海相碳酸盐烃源岩地球化学综合判识——以鄂尔多斯盆地为例［J］.中国科学（D辑），36(2):167-176.
王大锐，冯晓杰.2002.渤海湾地区下古生界碳、氧同位素地球化学研究［J］.地质学报，76(3):400-408.
王大锐，白玉雷，贾承造.1998.塔里木中、上奥陶统碳同位素组成正向偏移的石油地质学意义［J］.石油勘探与开发，25(4):15-16.
夏新宇，洪峰，赵林，等.1999.鄂尔多斯盆地下奥陶统碳酸盐岩有机相类型及生烃潜力［J］.沉积学报，17（4）:638-643.
张水昌， Wang R L，金之钧，等.2006.塔里木盆地寒武纪—奥陶纪优质烃源岩沉积与古环境变化的关系：碳氧同位素新证据［J］.地质学报，80（3）:459-466.
张水昌，张宝民，边立曾，等.2005.中国海相烃源岩发育控制因素［J］.地学前缘，12（3）:39-48.
左景勋，童金南，邱海鸥，等.2006.下扬子地区早三叠世碳酸盐岩碳同位素组成的演化特征［J］.中国科学（D辑），36(2):109-122.
Bergstrom S M，Chen X，Schmitz B， et al.2009.First documentation of the Ordovician Guttenberg δ¹³C excursion（GICE）in Asia: Chemostratigraphy of the Pagoda and Yanwashan formations in southeastern China［J］.Geological Magazine，146: 1-11.
Bergstrom S M，Young S，Schmitz B.2010.Katian（Upper Ordovician）δ¹³C chemostratigraphy and sequence stratigraphy in the United States and Baltoscandia: A regional comparison［J］.Palaeogeography，Palaeoclimatology，Palaeoecology，296(3-4): 217-234.
Derry L A，Brasier M D，Corfield R M， et al.1994.Sr and C isotopes in Lower Cambrian carbonates from the Siberian craton: A paleoenvironmental record during the ‘Cambrian explosion［J］.Earth and Planetary Science Letters，128(3-4): 671-681.
Hatch J R，Jacobson S R，Witzke B J， et al.1987.Possible late Middle Ordovician organic carbon isotope excursion: Evidence from Ordovician oils and hydrocarbon source rocks，Mid-Continent and east-central United States［J］.AAPG Bulletin，71(11):1342-1354.
Kaljo D，Martma T，Saadre T.2007.Post-Hunnebergian Ordovician carbon isotope trend in Baltoscandia，its environmental implications and some similarities with that of Nevada［J］.Palaeogeography，Palaeoclimatology，Palaeoecology，245(1-2): 138-155.
Kaufman A J，Jacobsen S B，Knoll A H.1993.The vendian record of Sr and C-isotopic variations in seawater: Implications for tectonic and paleoclimate［J］.Earth and Planetary Science Letters，120(3-4): 409-430.
Kaufman A J，Knoll A H.1995.Neoproterozoic variations in the C-isotopic composition of seawater: Stratigraphic and biogeochemical implications［J］.Precambrian Research，73(1-4): 27-49.
Qing H，Veizer J.1994.Oxygen and Carbon isotopic composition of Ordovician brachiopods: Implications for coeval seawater［J］.Geochimica et Cosmochimica Acta，58(20):4429-4442.
Saltzman M R，Young S A.2005.Long-lived glaciation in the Late Ordovician？Isotopic and sequence-stratigraphic evidence from western Laurentia［J］.Geology，33（2）: 109-112.
Shields G A，Carden G A F，Veizer J， et al.2003.Sr，C，and O isotope geochemistry of Ordovician brachiopods: A major isotopic event around the Middle-Late Ordovician transition［J］.Geochimica et Cosmochimica Acta，67(11):2005-2025.
Veizer J，Ala D，Azmy K， et al.1999. ⁸⁷Sr/⁸⁶Sr，δ¹³C and δ¹⁸O evolution of Phanerozoic seawater［J］.Chemical Geology，161(1-3): 59-88.
Wang K，Chatterton B D E，Wang Y.1997.An organic carbon isotope record of Late Ordovician to Early Silurian marine sedimentary rocks，Yangtze Sea，South China: Implications for CO₂ changes during the Hirnantian glaciation［J］.Palaeogeography，Palaeoclimatology，Palaeoecology，132(2):147-158.
Young S A，Saltzman M R，Bergstrom S M.2005.Upper Ordovician（Mohawkian）carbon isotope（δ¹³C）stratigraphy in eastern and central North America: Regional expression of a perturbation of the global carbon cycle［J］.Palaeogeography，Palaeoclimatology，Palaeoecology，222（1-2）: 53-76.
Young S A，Saltzman M R，Bergstrom S M， et al.2008.Paired δ¹³C_carb and δ¹³C_org records of Upper Ordovician（Sandbian-Katian）carbonates in North America and China: Implications for paleoceanographic change［J］.Palaeogeography，Palaeoclimatology，Palaeoecology，270(1-2): 166-178.

[1]	ZHANG Xiaoyang, DOU Yunfei, KONG Weijiang, LI Kang, LÜ Dawei, CHEN Jinfeng, JIA Haibo, SHEN Xiaoli. Sedimentation and reservoir characteristics of the aluminous-bearing strata of Benxi Formation in Linxing area,eastern margin of Ordos Basin [J]. Journal of Palaeogeography（Chinese Edition）, 2025, 27(2): 286-306.
[2]	WANG Jianpo, WANG Xiaofeng. Re-understanding of the Ordovician geographical division in China [J]. Journal of Palaeogeography（Chinese Edition）, 2025, 27(1): 16-16.
[3]	LI Yang. Extraction of astronomical cycle signals and identification of third-order sequences in the Ordovician of Well XT1, southern margin of Ordos Basin [J]. Journal of Palaeogeography（Chinese Edition）, 2025, 27(1): 209-224.
[4]	LIU Hengyu, LIU Mingjie, HAO Zhilei, REN Yin, WU Enyu, XU Han, ZHONG Shoukang, TAN Xiucheng, ZENG Wei, LIAN Chengbo, DAI Hongming. Pore formation and preservation mechanisms of ancient deep tight sandstone reservoirs: a case study of the Mesoproterozoic Changcheng System in Ordos Basin [J]. JOPC, 2024, 26(6): 1435-1451.
[5]	WANG Yan, WANG Nuoyu, YANG Debin, ZHANG Heng, ZHANG Juan, ZHANG Changjian, ZHANG Xiao. Characteristics and evolution mode of the Ordovician paleodrainage system architecture in northwestern Tahe oilfield,Tarim Basin,China [J]. JOPC, 2024, 26(6): 1467-1482.
[6]	LIU Mingcheng, WU Shenghe, WAN Xiaolong, LI Zhen, FAN Jianmin, CHEN Zhaohui, WANG Zifeng, LIU Haixu. Sequence stratigraphy and sedimentary facies characteristics of the shale strata of Yanchang Formation in Qingcheng Oilfield,Ordos Basin [J]. JOPC, 2024, 26(4): 779-795.
[7]	WEI Liubin, WANG Zongyan, LI Yi, PANG Zhichao, WANG Qianping, BAO Hongping, YANG Qiqi, WANG Zhen, SU Zhongtang, ZHANG Lijun. Classification and genesis of leopard skin(spot)carbonate rock: a case study of the Member 4 of Majiagou Formation in Ordos Basin [J]. JOPC, 2024, 26(4): 880-894.
[8]	WU Yuting, NING Meng, XIA Pan, QIAO Zhanfeng, YU Zhou, WEN Huaguo. Research on dolomitization process in dolomite-evaporite syngenetic system of the Majiagou Formation in Ordos Basin [J]. JOPC, 2024, 26(4): 895-910.
[9]	HUANG Yougen, XU Jie, ZHENG Xiaopeng, LIU Yan, ZHONG Shoukang, LI Lin, ZHANG Daofeng, TAN Xiucheng. Sedimentary characteristics and sedimentary models of the Lower Permian Taiyuan Formation limestone in mid-eastern Ordos Basin [J]. JOPC, 2024, 26(4): 911-925.
[10]	LI Hua, HE Youbin, YAO Fengnan, HE Yiming, JIANG Chunwei, ZHANG Xiankun, WU Jize, XU Yanxia, LIANG Jianshe. Contour current deposits in the Ordovician Kelimoli Formation,northwestern margin of Ordos Basin [J]. JOPC, 2024, 26(4): 962-971.
[11]	QI Rong, LI Guorong, ZHANG Juntao, WANG Fubin, LI Yuxiang, YANG Fei, LIU Lu, HE Sai, TIAN Jiaqi, LI Xiaoxiao. Mechanism and significance of hydrothermal activity in the Majiagou Formation,Fuxian area, Ordos Basin [J]. JOPC, 2024, 26(3): 632-643.
[12]	DING Xiaoqi, TIAN Yinyu, LEI Tao, ZHANG Wei, LI Xiaohui, GAO Jingyun. Control of Lüliang paleo-uplift on deposition of the Ordovician Majiagou Formation in Ordos Basin: evidence from Fugu outcrop in Shaanxi [J]. JOPC, 2024, 26(3): 671-682.
[13]	SHI Zhiqiang, PENG Shenyuan, ZHAO Ziteng. First identification and its geological significance of seafloor pockmarks sediments in the Upper Ordovician Wufeng Formation in China [J]. JOPC, 2024, 26(2): 255-268.
[14]	LI Yuanhao, SHI Lichuan, LEI Xiujie, DAN Weidong. Types and characteristics of load structures in the Upper Triassic Yanchang Formation,Ordos Basin [J]. JOPC, 2024, 26(2): 269-278.
[15]	LIU Guoqing, SU Zhongtang, HAO Zhilei, WEI Liubin, REN Junfeng, LIAO Huihong, WU Haowen. Microfacies and depositional model of a carbonate-evaporite symbiotic system of the Majiagou Formation in Ordos Basin [J]. JOPC, 2024, 26(2): 279-295.

Please choose a citation manager

Content to export