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Volume 41 Issue 5
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Article Navigation >  Acta Sedimentologica Sinica  > 2023  >  41(5): 1414-1429

ZHANG YunWang, JIN Xin, QIAO PeiJun, LI BinBing, HONG YanZhe, CHEN YuChao, LU Gang, DU YiXing, SHI ZhiQiang. Petrological and Geochemical Constraints on Sedimentary Provenance of the Fuxian Formation (Lower Jurassic) Sandstones in the Northeastern Ordos Basin[J]. Acta Sedimentologica Sinica, 2023, 41(5): 1414-1429. doi: 10.14027/j.issn.1000-0550.2022.154
Citation: ZHANG YunWang, JIN Xin, QIAO PeiJun, LI BinBing, HONG YanZhe, CHEN YuChao, LU Gang, DU YiXing, SHI ZhiQiang. Petrological and Geochemical Constraints on Sedimentary Provenance of the Fuxian Formation (Lower Jurassic) Sandstones in the Northeastern Ordos Basin[J]. Acta Sedimentologica Sinica, 2023, 41(5): 1414-1429. doi: 10.14027/j.issn.1000-0550.2022.154
shu

Petrological and Geochemical Constraints on Sedimentary Provenance of the Fuxian Formation (Lower Jurassic) Sandstones in the Northeastern Ordos Basin

doi: 10.14027/j.issn.1000-0550.2022.154
  • 1.

    Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China

  • 2.

    State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China

  • 3.

    State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China

  • 4.

    College of Energy, Chengdu University of Technology, Chengdu 610059, China

Funds:

Open Fund of State Key Laboratory of Marine Geology, Tongji University MG201903

  • Received Date: 2022-08-19
  • Accepted Date: 2023-02-09
  • Rev Recd Date: 2022-11-24
    • Available Online: 2023-02-09
  • Publish Date: 2023-10-10
  • The Ordos Basin, located in the western North China Block, is found at the junction between the stable area of eastern China and the active belt of western China. It is located between the ancient Asian and Qinqi-Kun oceans （Shangdan Ocean） of the Proto-Tethys Ocean. Therefore, the Ordos Basin is a natural laboratory for studying the Ancient Asian and Tethys tectonic domains. The provenance system of the Ordos Basin is key to understanding the tectonic evolution of the Tethyan and Paleo-Asian oceanic domains. At present, the provenance system of the Lower Jurassic in the Ordos Basin is concentrated in the central and southwestern parts of the basin, while the Early Jurassic provenance system in the northeastern Ordos Basin remains unclear. To address this scientific question, we conducted this study on the Anya section located 40 km NE of Yulin city, northern Ordos Basin. We collected 10 sandstone samples from the Fuxian Formation for petrological analysis and 6 for element geochemical analysis. This study used the Gazzi-Dickinson counting method to classify the sandstone composition. The surface dust and weathered portions of samples were removed with a rasper and then washed with deionized water. After 8 hours of oven drying at 50 °C, samples were ground into powder using agate mortars. Sample preparations were completed in the School of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology. Approximately 30⁃50 mg of powdered sample were digested with HF+HNO3+HClO4 mixed acid, and then inductively coupled plasma-optical emission （ICP-OES； IRIS Advantage） and inductively coupled plasma-mass spectrometry （ICP-MS； Thermo VG-X7） were used to determine the major and trace elements at the State Key Laboratory of Marine Geology, Tongji University, Shanghai. International standards （BHVO-2, W-2a, GSP-2, GSD-9）； blank samples were utilized for monitoring during the analytical process, and the relative deviations of the detected data were less than 5%. Results show that the sandstones of the Fuxian Formation in the study area are composed of feldspar lithic quartz and lithic quartz sandstones. Major and trace elements contents of all samples from the Anya section are similar, indicating that the Fuxian Formation has a single provenance system. The La/Yb-∑REE, Hf-La/Th, and Co/TH-La/Sc diagrams, together with the characteristics of lithic fragments, reveal that the parent rocks of the Fuxian Formation were intermediate acid magmatic and metamorphic rocks. The Dickinson plot indicates that the main provenance of the Fuxian Formation sandstones was formed in the tectonic setting of the recycled orogenic belt. The distribution of rare earth elements （REEs） is flat and exhibits a "lean slowly to the right" pattern. Comparing REE distribution models to that of surrounding potential source areas reveals that those of the Fuxian Formation sandstones are comparable to that of Yinshan orogenic belt. As a result, we concluded that the main provenance area of the Fuxian Formation in the northeastern Ordos Basin is the Yinshan orogenic belt, which is further supported by paleocurrent data from previous work. From the Permian to the Triassic, the root of the oceanic crust formed by the subduction of the ancient Asian Ocean block fractured and disintegrated, causing a large amount of granite to penetrate the Yinshan orogenic belt, weathered and denuded during the Early-Middle Jurassic, and transported to the northeastern Ordos Basin by the Jinshaan-Guhe River.
  • [1] He Z J, Li J Y, Mo S G, et al. Geochemical discriminations of sandstones from the Mohe foreland basin, northeastern China： Tectonic setting and provenance[J]. Science in China Series D： Earth Sciences, 2005, 48（5）： 613-621.
    [2] 杨仁超,李进步,樊爱萍,等. 陆源沉积岩物源分析研究进展与发展趋势[J]. 沉积学报,2013,31（1）：99-107.

    Yang Renchao, Li Jinbu, Fan Aiping, et al. Research progress and development tendency of provenance analysis on terrigenous sedimentary rocks[J]. Acta Sedimentologica Sinica, 2013, 31（1）： 99-107.
    [3] 杨守业,李从先,张家强. 苏北滨海平原全新世沉积物物源研究：元素地球化学与重矿物方法比较[J]. 沉积学报,1999,17（3）：458-463.

    Yang Shouye, Li Congxian, Zhang Jiaqiang. Provenance study of Holocene sediments in Subei coastal plain： Comparison between elemental geochemistry and heavy mineral methods[J]. Acta Sedimentologica Sinica, 1999, 17（3）： 458-463.
    [4] Roser B P, Korsch R J. Provenance signatures of sandstone-mudstone suites determined using discriminant function analysis of major-element data[J]. Chemical Geology, 1988, 67（1/2）： 119-139.
    [5] Floyd P A, Leveridge B E. Tectonic environment of the Devonian Gramscatho Basin, south Cornwall： Framework mode and geochemical evidence from turbiditic sandstones[J]. Journal of the Geological Society, 1987, 144（4）： 531-542.
    [6] Crichton J G, Condie K C. Trace elements as source indicators in cratonic sediments： A case study from the Early Proterozoic Libby Creek Group, southeastern Wyoming[J]. The Journal of Geology, 1993, 101（3）： 319-332.
    [7] Nesbitt H W, Young G M. Early Proterozoic climates and plate motions inferred from major element chemistry of lutites[J]. Nature, 1982, 299（5885）： 715-717.
    [8] Kimberley M M, Grandstaff D E. Profiles of elemental concentrations in Precambrian paleosols on basaltic and granitic parent materials[J]. Precambrian Research, 1986, 32（2/3）： 133-154.
    [9] Taylor S R, Mclennan S M. The continental crust： Its composition and evolution[M]. Oxford： Blackwell Scientific Publication, 1985.
    [10] McLennan S M, Hemming S, McDaniel D K, et al. Geochemical approaches to sedimentation, provenance, and tectonics[M]//Johnsson M J, Basu A. Processes controlling the composition of clastic sediments. Boulder： Geological Society of America, 1993： 21-40.
    [11] 赵俊兴,陈洪德,张锦泉. 鄂尔多斯盆地下侏罗统富县组沉积体系及古地理[J]. 岩相古地理,1999,19（5）：40-46.

    Zhao Junxing, Chen Hongde, Zhang Jinquan. The depositional systems and palaeogeography of the Lower Jurassic Fuxian Formation in the Ordos Basin[J]. Sedimentary Geology and Tethyan Geology, 1999, 19（5）： 40-46.
    [12] 杨俊杰. 鄂尔多斯盆地构造演化与油气分布规律[M]. 北京：石油工业出版社,2002：228.

    Yang Junjie. Tectonic evolution and oil-gas reservoirs distribution in Ordos Basin[M]. Beijing： Petroleum Industry Press, 2002： 228.
    [13] 吕振华,齐亚林,孟令涛. 鄂尔多斯盆地西北部地区侏罗系成藏主控因素研究[J]. 新疆石油天然气,2016,12（1）：19-24.

    Zhenhua Lü, Qi Yalin, Meng Lingtao. Factors of Jurassic reservoir master northwestern of Ordos Basin[J]. Xinjiang Oil & Gas, 2016, 12（1）： 19-24.
    [14] 李宝芳,李祯,林畅松,等. 鄂尔多斯盆地中部下中侏罗统沉积体系和层序地层[M]. 北京：地质出版社,1995：27-83.

    Li Baofang, Li Zhen, Lin Changsong, et al. Depositional systems and sequence stratigraphy of the Lower and Middle Jurassic strata in the middle part of the Ordos Basin[M]. Beijing： Geological Publishing House, 1995： 27-83.
    [15] 李昌昊,葛禹,金鑫,等. 鄂尔多斯盆地早侏罗世富县期沉积演化：大洋缺氧事件前后陆地气候变化的响应[J]. 古地理学报,2022,24（4）：697-712.

    Li Changhao, Ge Yu, Jin Xin, et al. Sedimentological evolution during the Early Jurassic Fuxian period in Ordos Basin： Palaeoclimatic response to Toarcian Oceanic Anoxic Event[J]. Journal of Palaeogeography, 2022, 24（4）： 697-712.
    [16] 时志强,韩永林,张锦泉. 鄂尔多斯盆地早侏罗世富县期岩相古地理特征[J]. 矿物岩石,2001,21（3）：124-127.

    Shi Zhiqiang, Han Yonglin, Zhang Jinquan. Lithofacies paleogeography of Fuxian stage in Early Jurassic in Ordos Basin[J]. Journal of Mineralogy and Petrology, 2001, 21（3）： 124-127.
    [17] 时志强,韩永林,赵俊兴. 鄂尔多斯盆地早侏罗世富县期冲积扇沉积[J]. 成都理工学院学报,2002,29（4）：390-393.

    Shi Zhiqiang, Han Yonglin, Zhao Junxing. Fans at the Early Jurassic Fuxian stage in Ordos Basin[J]. Journal of Chengdu University of Technology, 2002, 29（4）： 390-393.
    [18] 刘犟,李凤杰,侯景涛,等. 鄂尔多斯盆地吴起地区下侏罗统富县组沉积相特征[J]. 岩性油气藏,2012,24（3）：74-78.

    Liu Jiang, Li Fengjie, Hou Jingtao, et al. Sedimentary facies of the Lower Jurassic Fuxian Formation in Wuqi area, Ordos Basin[J]. Lithologic Reservoirs, 2012, 24（3）： 74-78.
    [19] 郑小杰. 陕北斜坡中东部早中侏罗世沉积体系及油气富集规律研究：以安塞油田南部为例[D]. 西安：长安大学,2009.

    Zheng Xiaojie. Study on sedimentary system and oil-gas enrichment regularities of Early-Middle Jurassic in mid-eastern Shanbei slope： Take southern Ansai oilfield for instance[D]. Xi'an： Chang'an University, 2009.
    [20] 刘玄春. 鄂尔多斯盆地环县地区侏罗系富县组—延10油层组古地貌分析及沉积相特征研究[D]. 成都：成都理工大学,2018.

    Liu Xuanchun. Paleogeomorphic analysis and sedimentary facies characteristics of Jurassic Fuxian-Yan 10 reservoir group in Huanxian area, Ordos Basin[D]. Chengdu： Chengdu University of Technology, 2018.
    [21] 计波,焦养泉,刘阳. 鄂尔多斯盆地东北部下侏罗统富县组底部石英砂岩成因与物源[J]. 地质通报,2022,41（9）：1601-1612.

    Ji Bo, Jiao Yangquan, Liu Yang. Petrogenesis and provenance of the quartz sandstone from the bottom of Lower Jurassic Fuxian Formation, northeastern Ordos Basin[J]. Geological Bulletin of China, 2022, 41（9）： 1601-1612.
    [22] 朱广社. 鄂尔多斯盆地晚三叠世—中侏罗世碎屑岩、沉积、层序充填过程及其成藏效应[D]. 成都：成都理工大学,2014.

    Zhu Guangshe. Sedimentary, sequence filling process and its accumulation effect of Late Triassic to Middle Jurassic in Ordos Basin[D]. Chengdu： Chengdu University of Technology, 2014.
    [23] 何自新. 鄂尔多斯盆地演化与油气[M]. 北京：石油工业出版社,2003：66-83.

    He Zixin. Evolution and hydrocarbon in Ordos Basin[M]. Beijing： Petroleum Industry Press, 2003： 66-83.
    [24] 王双明. 鄂尔多斯盆地构造演化和构造控煤作用[J]. 地质通报,2011,30（4）：544-552.

    Wang Shuangming. Ordos Basin tectonic evolution and structural control of coal[J]. Geological Bulletin of China, 2011, 30（4）： 544-552.
    [25] 刘池洋,王建强,张东东,等. 鄂尔多斯盆地油气资源丰富的成因与赋存—成藏特点[J]. 石油与天然气地质,2021,42（5）：1011-1029.

    Liu Chiyang, Wang Jianqiang, Zhang Dongdong, et al. Genesis of rich hydrocarbon resources and their occurrence and accumulation characteristics in the Ordos Basin[J]. Oil & Gas Geology, 2021, 42（5）： 1011-1029.
    [26] 杨华,席胜利,魏新善,等. 鄂尔多斯多旋回叠合盆地演化与天然气富集[J]. 中国石油勘探,2006（1）：17-24.

    Yang Hua, Xi Shengli, Wei Xinshan, et al. Evolution and natural gas enrichment of multicycle superimposed basin in Ordos Basin[J]. China Petroleum Exploration, 2006（1）： 17-24.
    [27] 旷理雄,梁力文,敬小军,等. 从前侏罗纪古地貌的角度论鄂尔多斯盆地靖边：鄂托克前旗地区油气成藏模式[J]. 中国有色金属学报,2012,22（3）：837-843.

    Kuang Lixiong, Liang Liwen, Jing Xiaojun, et al. Accumulation model of Jingbian： Etuokeqianqi area in Ordos Basin from angle of pre-Jurassic palaeogeomorphology[J]. The Chinese Journal of Nonferrous Metals, 2012, 22（3）： 837-843.
    [28] 张之辉. 鄂尔多斯盆地东北缘早—中侏罗世延安组成煤期古环境与古气候[D]. 北京：中国地质大学（北京）,2020.

    Zhang Zhihui. Paleoenvironment and paleoclimate of Early-Middle Jurassic Yan'an Formation coal-forming period in the northeast margin Ordos Basin[D]. Beijing： China University of Geosciences （Beijing）, 2020.
    [29] 贾本文. 鄂尔多斯盆地东南部侏罗系延安组延10物源分析[D]. 西安：长安大学,2020.

    Jia Benwen. Provenance analysis of Yan 10 in Yan'an Formation of Jurassic in the southeast of Ordos Basin[D]. Xi'an： Chang'an University, 2020.
    [30] 刘池洋,赵红格,王锋,等. 鄂尔多斯盆地西缘（部）中生代构造属性[J]. 地质学报,2005,79（6）：737-747.

    Liu Chiyang, Zhao Hongge, Wang Feng, et al. Attributes of the Mesozoic structure on the west margin of the Ordos Basin[J]. Acta Geologica Sinica, 2005, 79（6）： 737-747.
    [31] 杨华, 陈洪德, 付金华. 鄂尔多斯盆地晚三叠世沉积地质与油藏分布规律[M]. 科学出版社, 2012： 3-15．

    Yang Hua, Chen Hongde, Fu Jinhua ．The Late Triassic sedimentary geology and distribution rule of oil reservoirs in the Ordos Basin [M]. Beijing： Science Publishing House,2012： 3-15.
    [32] 袁效奇,傅智雁,王喜富,等. 中国北方侏罗系（V）鄂尔多斯地层区[M]. 北京：石油工业出版社,2003：54-94.

    Yuan Xiaoqi, Fu Zhiyan, Wang Xifu, et al. Jurassic system in the north of China （V） Odros stratigraphic region[J]. Beijing： Petroleum Industry Press, 2003： 54-94.
    [33] Jin X, Shi Z Q, Baranyi V, et al. The Jenkyns Event （early Toarcian OAE） in the Ordos Basin, North China[J]. Global and Planetary Change, 2020, 193： 103273.
    [34] Jin X, Zhang F, Baranyi V, et al. Early Jurassic massive release of terrestrial mercury linked to floral crisis[J]. Earth and Planetary Science Letters, 2022, 598： 117842.
    [35] 葛道凯,杨起,付泽明,等. 陕西榆林侏罗纪煤系基底古侵蚀面的地貌特征及其对富县组沉积作用的控制[J]. 沉积学报,1991,9（3）：65-73.

    Ge Daokai, Yang Qi, Fu Zeming, et al. The palaeornorphologic features of the basement of the Jurassic coal measures and its control on the sedimentation of Fuxian Formation in Yulin, Shaanxi[J]. Acta Sedimentologica Sinica, 1991, 9（3）： 65-73.
    [36] 阎存凤. 陕西榆林一横山地区富县组孢粉组合[J]. 植物学报,1992,34（8）：634-640.

    Yan Cunfeng. The sporo-pollen assemblage from Fuxian Formation in Yulin-Hengshan region, Shaanxi province[J]. Acta Botanica Sinica, 1992, 34（8）： 634-640.
    [37] Them II T R, Gill B C, Caruthers A H, et al. Thallium isotopes reveal protracted anoxia during the Toarcian （Early Jurassic） associated with volcanism, carbon burial, and mass extinction[J]. Proceedings of the National Academy of Sciences of the United States of America, 2018, 115（26）： 6596-6601.
    [38] Kemp D B, Baranyi V, Izumi K, et al. Organic matter variations and links to climate across the early Toarcian Oceanic Anoxic Event （T-OAE） in Toyora area, southwest Japan[J]. Palaeogeography, Palaeoclimatology, Palaeoecology, 2019, 530： 90-102.
    [39] 胡修棉. 东特提斯洋晚中生代—古近纪重大事件研究进展[J]. 自然杂志,2015,37（2）：93-102.

    Hu Xiumian. Overview of the Late Mesozoic Paleogene major paleoceanographic and geological events in eastern Tethyan ocean[J]. Chinese Journal of Nature, 2015, 37（2）： 93-102.
    [40] Them T R, Gill B C, Selby D, et al. Evidence for rapid weathering response to climatic warming during the Toarcian Oceanic Anoxic Event[J]. Scientific Reports, 2017, 7（1）： 5003.
    [41] Kemp D B, Selby D, Izumi K. Direct coupling between carbon release and weathering during the Toarcian Oceanic Anoxic Event[J]. Geology, 2020, 48（10）： 976-980.
    [42] 马收先,孟庆任,曲永强. 轻矿物物源分析研究进展[J]. 岩石学报,2014,30（2）：597-608.

    Ma Shouxian, Meng Qingren, Qu Yongqiang. Development on provenance analysis of light minerals[J]. Acta Petrologica Sinica, 2014, 30（2）： 597-608.
    [43] Dickinson W R. Interpreting detrital modes of Graywacke and Arkose[J]. Journal of Sedimentary Research, 1970, 40（2）： 695-707.
    [44] 李怡佳,阮壮,刘帅,等. 鄂尔多斯盆地南缘长10—长8段物源及源区构造背景研究[J]. 现代地质,2020,34（4）：784-799,811.

    Li Yijia, Ruan Zhuang, Liu Shuai, et al. Provenance and tectonic setting of Chang 10-Chang 8 member in the southern Ordos Basin[J]. Geoscience, 2020, 34（4）： 784-799, 811.
    [45] Rudnick R L, Gao S. Composition of the continental crust[M]//Rudnick R L. The crust. Oxford： Elsevier, 2003： 1-64.
    [46] 李蒙,赵红格,李文厚,等. 贺兰山地区晚三叠世沉积主微量元素物源分析及方法探讨[J]. 高校地质学报,2018,24（6）：841-855.

    Li Meng, Zhao Hongge, Li Wenhou, et al. Major and trace elements of the Late Triassic strata in the Helan Mountain： Constraints on the provenance and discussions on different methods[J]. Geological Journal of China Universities, 2018, 24（6）： 841-855.
    [47] Boynton W V. Cosmochemistry of the rare earth elements： Meteorite studies[J]. Developments in Geochemistry, 1984, 2： 63-114.
    [48] 张瑜,杨华,王多云,等. 鄂尔多斯盆地南部铜川组碎屑岩地球化学特征及其对物源的制约[J]. 天然气地球科学,2014,25（8）：1233-1241.

    Zhang Yu, Yang Hua, Wang Duoyun, et al. Geochemical features of the detrital rocks of Tongchuan Formation in the southern Ordos Basin and its constrains on provenance[J]. Natural Gas Geoscience, 2014, 25（8）： 1233-1241.
    [49] Floyd P A, Winchester J A, Park R G. Geochemistry and tectonic setting of Lewisian clastic metasediments from the Early Proterozoic Loch Maree Group of Gairloch, NW Scotland[J]. Precambrian Research, 1989, 45（1/2/3）： 203-214.
    [50] Allègre C J, Minster J F. Quantitative models of trace element behavior in magmatic processes[J]. Earth and Planetary Science Letters, 1978, 38（1）： 1-25.
    [51] Gu X X, Liu J M, Zheng M H, et al. Provenance and tectonic setting of the Proterozoic turbidites in Hunan, South China： Geochemical evidence[J]. Journal of Sedimentary Research, 2002, 72（3）： 393-407.
    [52] 毛光周,刘池洋. 地球化学在物源及沉积背景分析中的应用[J]. 地球科学与环境学报,2011,33（4）：337-348.

    Mao Guangzhou, Liu Chiyang. Application of geochemistry in provenance and depositional setting analysis[J]. Journal of Earth Sciences and Environment, 2011, 33（4）： 337-348.
    [53] Dickinson W R, Suczek C A. Plate tectonics and sandstone compositions[J]. AAPG Bulletin, 1979, 63（12）： 2164-2182.
    [54] Dickinson W R. Interpreting provenance relations from detrital modes of sandstones[M]//Zuffa G G. Provenance of arenites. Dordrecht： Springer, 1985： 333-361.
    [55] Weltje G J. Ternary sandstone composition and provenance： An evaluation of the 'Dickinson model'[M]//Buccianti A, Mateu-Figueras G, Pawlowsky-Glahn V. Compositional data analysis in the geosciences： From theory to practice. London： Geological Society, 2006： 79-99.
    [56] Weltje G J. Quantitative analysis of detrital modes： Statistically rigorous confidence regions in ternary diagrams and their use in sedimentary petrology[J]. Earth-Science Reviews, 2002, 57（3/4）： 211-253.
    [57] 魏红红. 鄂尔多斯地区石炭—二叠系沉积体系及层序地层学研究[D]. 西安：西北大学,2002.

    Wei Honghong. Research on Permian-Carboniferous depositional systems and the sequence stratigraphy of Ordos area[D]. Xi'an： Northwestern University, 2002.
    [58] 宋凯,吕剑文,杜金良,等. 鄂尔多斯盆地中部上三叠统延长组物源方向分析与三角洲沉积体系[J]. 古地理学报,2002,4（3）：59-66.

    Song Kai, Jianwen Lü, Du Jinliang, et al. Source direction analysis and delta depositional systems of Yanchang Formation of the Upper Triassic in the central Ordos Basin[J]. Journal of Palaeogeography, 2002, 4（3）： 59-66.
    [59] 王晓霞,王涛,李伍平. 秦岭杂岩中花岗质片麻岩体的岩石地球化学特征及成因[J]. 矿物岩石,1997,17（3）：76-82.

    Wang Xiaoxia, Wang Tao, Li Wuping. The geochemistry characteristics and genesis of the granitic gneisses in Qinling complex[J]. Journal of Mineralogy and Petrology, 1997, 17（3）： 76-82.
    [60] 朱碧,刘倩,杨涛. 基体差异对电感耦合等离子体质谱法测定过程中Ba氧化物产率的影响及其对Eu测定结果校正的研究[J]. 高校地质学报,2016,22（3）：467-473.

    Zhu Bi, Liu Qian, Yang Tao. Matrix effect on barium oxide and hydroxide formation during ICP-MS measurement and its implication for Eu correction[J]. Geological Journal of China Universities, 2016, 22（3）： 467-473.
    [61] Paytan A, Griffith E M. Marine barite： Recorder of variations in ocean export productivity[J]. Deep Sea Research Part II： Topical Studies in Oceanography, 2007, 54（5/6/7）： 687-705.
    [62] Griffith E M, Paytan A. Barite in the ocean-occurrence, geochemistry and palaeoceanographic applications[J]. Sedimentology, 2012, 59（6）： 1817-1835.
    [63] Xu W M, Ruhl M, Jenkyns H C, et al. Carbon sequestration in an expanded lake system during the Toarcian Oceanic Anoxic Event[J]. Nature Geoscience, 2017, 10（2）： 129-134.
    [64] 陈安清,陈洪德,徐胜林,等. 鄂尔多斯盆地北部晚古生代沉积充填与兴蒙造山带“软碰撞”的耦合[J]. 吉林大学学报（地球科学版）,2011,41（4）：953-965.

    Chen Anqing, Chen Hongde, Xu Shenglin, et al. Sedimentary filling of north Ordos and their implications for the soft collision process of Hing Gan Mts. -Mongolia orogenic belt in Late Paleozoic[J]. Journal of Jilin University （Earth Science Edition）, 2011, 41（4）： 953-965.
    [65] 刘伟,杨进辉,李潮峰. 内蒙赤峰地区若干主干断裂带的构造热年代学[J]. 岩石学报,2003,19（4）：717-728.

    Liu Wei, Yang Jinhui, Li Chaofeng. Thennochronology of three major faults in the Chifeng area, Inner Mongolia of China[J]. Acta Petrologica Sinica, 2003, 19（4）： 717-728.
    [66] 陈全红,李文厚,刘昊伟,等. 鄂尔多斯盆地上石炭统—中二叠统砂岩物源分析[J]. 古地理学报,2009,11（6）：629-640.

    Chen Quanhong, Li Wenhou, Liu Haowei, et al. Provenance analysis of sandstone of the Upper Carboniferous to Middle Permian in Ordos Basin[J]. Journal of Palaeogeography, 2009, 11（6）： 629-640.
    [67] 张拴宏,赵越,刘建民,等. 华北地块北缘晚古生代—早中生代岩浆活动期次、特征及构造背景[J]. 岩石矿物学杂志,2010,29（6）：824-842.

    Zhang Shuanhong, Zhao Yue, Liu Jianmin, et al. Geochronology, geochemistry and tectonic setting of the Late Paleozoic-Early Mesozoic magmatism in the northern margin of the North China Block： A preliminary review[J]. Acta Petrologica et Mineralogica, 2010, 29（6）： 824-842.
    [68] 石鑫. 鄂尔多斯盆地东北缘中下侏罗统碎屑物源分析及其对盆山演化的启示[D]. 成都：成都理工大学,2018.

    Shi Xin. The provenance of the Middle-Lower Jurrasic clastic rocks in the northestern Ordos Basin and its implication to basin-range evolution[D]. Chengdu： Chengdu University of Technology, 2018.
    [69] 赵俊兴, 陈洪德. 鄂尔多斯盆地侏罗纪早中期甘陕古河的演化变迁[J]. 石油与天然气地质, 2006,27（2）： 152-158.

    Zhao Junxing, Chen Hongde. Evolution of Gan-Shaan paleochannel during Early and Middle Jurassic in Ordos Basin[J]. Oil & Gas Geology, 2006, 27（2）： 152-158.
    [70] 苏三. 鄂尔多斯东北缘中生代盆地演化及其对太行山区构造作用的指示[D]. 北京：中国地质大学（北京）, 2008.

    Su San. Mesozoic sedimentary evolution in northeastern Ordos and its tectonic implication to Taihang Shan area[D]. Beijing： China University of Geosciences （Beijing）, 2008.
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  • Received:  2022-08-19
  • Revised:  2022-11-24
  • Accepted:  2023-02-09
  • Published:  2023-10-10

Petrological and Geochemical Constraints on Sedimentary Provenance of the Fuxian Formation (Lower Jurassic) Sandstones in the Northeastern Ordos Basin

doi: 10.14027/j.issn.1000-0550.2022.154
  • 1. Institute of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China
  • 2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China
  • 3. State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China
  • 4. College of Energy, Chengdu University of Technology, Chengdu 610059, China
Funds:

Open Fund of State Key Laboratory of Marine Geology, Tongji University MG201903

  • Received Date: 2022-08-19
  • Accepted Date: 2023-02-09
  • Rev Recd Date: 2022-11-24
  • Available Online: 2023-02-09
  • Publish Date: 2023-10-10

Abstract: The Ordos Basin, located in the western North China Block, is found at the junction between the stable area of eastern China and the active belt of western China. It is located between the ancient Asian and Qinqi-Kun oceans （Shangdan Ocean） of the Proto-Tethys Ocean. Therefore, the Ordos Basin is a natural laboratory for studying the Ancient Asian and Tethys tectonic domains. The provenance system of the Ordos Basin is key to understanding the tectonic evolution of the Tethyan and Paleo-Asian oceanic domains. At present, the provenance system of the Lower Jurassic in the Ordos Basin is concentrated in the central and southwestern parts of the basin, while the Early Jurassic provenance system in the northeastern Ordos Basin remains unclear. To address this scientific question, we conducted this study on the Anya section located 40 km NE of Yulin city, northern Ordos Basin. We collected 10 sandstone samples from the Fuxian Formation for petrological analysis and 6 for element geochemical analysis. This study used the Gazzi-Dickinson counting method to classify the sandstone composition. The surface dust and weathered portions of samples were removed with a rasper and then washed with deionized water. After 8 hours of oven drying at 50 °C, samples were ground into powder using agate mortars. Sample preparations were completed in the School of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology. Approximately 30⁃50 mg of powdered sample were digested with HF+HNO3+HClO4 mixed acid, and then inductively coupled plasma-optical emission （ICP-OES； IRIS Advantage） and inductively coupled plasma-mass spectrometry （ICP-MS； Thermo VG-X7） were used to determine the major and trace elements at the State Key Laboratory of Marine Geology, Tongji University, Shanghai. International standards （BHVO-2, W-2a, GSP-2, GSD-9）； blank samples were utilized for monitoring during the analytical process, and the relative deviations of the detected data were less than 5%. Results show that the sandstones of the Fuxian Formation in the study area are composed of feldspar lithic quartz and lithic quartz sandstones. Major and trace elements contents of all samples from the Anya section are similar, indicating that the Fuxian Formation has a single provenance system. The La/Yb-∑REE, Hf-La/Th, and Co/TH-La/Sc diagrams, together with the characteristics of lithic fragments, reveal that the parent rocks of the Fuxian Formation were intermediate acid magmatic and metamorphic rocks. The Dickinson plot indicates that the main provenance of the Fuxian Formation sandstones was formed in the tectonic setting of the recycled orogenic belt. The distribution of rare earth elements （REEs） is flat and exhibits a "lean slowly to the right" pattern. Comparing REE distribution models to that of surrounding potential source areas reveals that those of the Fuxian Formation sandstones are comparable to that of Yinshan orogenic belt. As a result, we concluded that the main provenance area of the Fuxian Formation in the northeastern Ordos Basin is the Yinshan orogenic belt, which is further supported by paleocurrent data from previous work. From the Permian to the Triassic, the root of the oceanic crust formed by the subduction of the ancient Asian Ocean block fractured and disintegrated, causing a large amount of granite to penetrate the Yinshan orogenic belt, weathered and denuded during the Early-Middle Jurassic, and transported to the northeastern Ordos Basin by the Jinshaan-Guhe River.

ZHANG YunWang, JIN Xin, QIAO PeiJun, LI BinBing, HONG YanZhe, CHEN YuChao, LU Gang, DU YiXing, SHI ZhiQiang. Petrological and Geochemical Constraints on Sedimentary Provenance of the Fuxian Formation (Lower Jurassic) Sandstones in the Northeastern Ordos Basin[J]. Acta Sedimentologica Sinica, 2023, 41(5): 1414-1429. doi: 10.14027/j.issn.1000-0550.2022.154
Citation: ZHANG YunWang, JIN Xin, QIAO PeiJun, LI BinBing, HONG YanZhe, CHEN YuChao, LU Gang, DU YiXing, SHI ZhiQiang. Petrological and Geochemical Constraints on Sedimentary Provenance of the Fuxian Formation (Lower Jurassic) Sandstones in the Northeastern Ordos Basin[J]. Acta Sedimentologica Sinica, 2023, 41(5): 1414-1429. doi: 10.14027/j.issn.1000-0550.2022.154
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0.   引言

  • 20世纪80年代,元素地球化学方法开始被学者运用到地质构造复杂区域的研究工作中,当前已成为一种重要的分析手段[1⁃2]。一些元素（如Th、Sc、Co、Zr、Hf、Ga、Nb等）在母岩的风化、剥蚀、搬运、沉积及成岩过程中不易迁移,几乎被等量地搬运到碎屑沉积物中,因此可以用于物源示踪[2⁃3]。元素地球化学结合岩石学特征可以来判断沉积物母岩岩性[4⁃6]、风化程度[7⁃8]、沉积物搬运距离[9⁃10]及源区大地构造背景[4]等。

    鄂尔多斯盆地是形成于中生代的内陆坳陷沉积盆地,也是我国最大的内陆含油气盆地和含煤盆地之一[11⁃12]。盆地内下侏罗统富县组地层沉积厚度较大、油藏丰富,是鄂尔多斯盆地中生界油气勘探开发的重要层系[11,13]。前人对于富县组的研究多聚焦于沉积环境等方面,认为鄂尔多斯盆地富县组主要发育浅湖相[14⁃15]、河流相[11,15]、冲积扇—河流相[11,16⁃17]及三角洲相[18]。而对源—汇系统这一研究方向及油气勘探领域的热点问题研究还较薄弱,只有少数学者对本次研究区邻区富县组的物源体系进行过研究,认为鄂尔多斯盆地中部（陕北斜坡中东部）富县组沉积时期物源主要来自北部、西北部及西部[19]；盆地西南环县地区富县组时期物源方向为西南部[20]；有学者以鄂尔多斯东北部考考乌素沟一带富县组底部的一套纯净石英砂岩为研究对象,通过沉积学、岩石学及元素地球化学等方法对富县组底部砂岩进行了物源分析,认为其物源为盆地内部隆起提供的富含石英质沉积岩,可能是延长组顶部长石砂岩风化蚀变形成的富含石英与高岭石的源区物质[21]。

    此外,鄂尔多斯盆地位于华北克拉通的西部,处于中国西部活动带和东部稳定区域之间的结合部位,在全球构造中,介于古亚洲洋与原特提斯洋中的秦祁昆洋（商丹洋）之间,周缘被加里东造山带包围[22]。盆地北侧的古亚洲洋俯冲、西南缘和南缘秦—祁海槽及其派生的贺兰坳拉槽的扩张、俯冲、消减控制了鄂尔多斯盆地的演化[22]。因此,鄂尔多斯盆地是研究古亚洲构造域和古特提斯构造域的天然实验室,其盆—山演化一直是学者们关注的焦点。开展鄂尔多斯盆地物源研究,对探讨该地区的盆—山关系具有重要意义。然而,前人的研究主要在本次研究区（鄂尔多斯盆地东北部榆林地区）的周边地区,对于研究区富县组沉积时期的物源体系还缺乏研究。

    通过岩石学和元素地球化学等研究手段,以鄂尔多斯盆地东北部榆林地区安崖剖面为研究对象,利用富县组砂岩的地球化学特征和岩石学特征分析了富县组沉积物的物质来源、源区构造背景,并结合周缘潜在源区的稀土元素数据对富县组时期的物源体系进行了探讨,以期厘定鄂尔多斯盆地东北部富县组沉积时期的物源体系,进而完善整个鄂尔多斯盆地早侏罗世物源体系,为华北克拉通盆—山演化提供相应的证据。

1.   区域地质背景

  • 鄂尔多斯盆地位于中国大陆中部,是一个多旋回叠合型盆地,是我国仅次于塔里木盆地的第二大沉积盆地,也是我国形成历史最早、演化时间最长的盆地之一[23]。盆地东隔汾渭地堑与太行山相望,西翼以桌子山—贺兰山—六盘山为界,北翼以大青山—阴山造山带为界,南部以北祁连—秦岭造山带为界,横跨陕、甘、宁、蒙、晋,整体呈南北向矩形,面积约25×104 km2。广义的鄂尔多斯盆地包括周边河套、银川、渭河等新生代断陷盆地,总面积约36×104 km2[12,24⁃25]。

    盆地在构造位置上位于华北克拉通的西部,其形成和演化与华北板块的演化存在密切联系。据前人研究,可以将鄂尔多斯盆地的构造演化分为太古—古元古代的盆地基底形成、中—新元古代的拗拉槽裂陷演化、早古生代的浅海台地演化、晚古生代的克拉通坳陷演化、中生代内陆盆地演化及新生代周缘断陷盆地演化等六个阶段[11⁃12,22,26]。根据现在盆地的构造形态,可划分为伊盟隆起、伊陕斜坡、渭北隆起、天环坳陷、晋西挠褶带及西缘冲断带等六个一级构造单元[15,27⁃30]（图1a）。

    Figure 1.  Tectonic units and location of the Anya section in the Ordos Basin

    盆地内沉积地层发育齐全,从元古界开始,仅缺失志留系、泥盆系及下石炭统[31]。其侏罗系为稳定型内陆盆地沉积,尽管部分地区由于基底隆起或顶部遭受冲刷（或剥蚀）变薄以及部分地层发育不全,但侏罗系在全盆地均有发育,尤其在盆地东南缘的延安、甘泉等地都有大面积的连续出露,沉积地层自下而上分为富县组（J1 f）、延安组（J1-2 y）、直罗组（J2 z）、安定组（J2a）、芬芳河组（J3 f）（图1b,c）。盆地内侏罗系与下伏的上三叠统呈区域微角度不整合接触关系,其上与下白垩统志丹群为角度不整合接触[32]。

2.   安崖剖面研究现状

  • 安崖剖面（38°24'00" N；110°11'48" E）位于鄂尔多斯东北部（图1a）,距离榆林市约40 km。安崖剖面厚度约49 m（图2）[15,33⁃34],剖面0~2.0 m岩性为中层砂岩与薄层灰白色粉砂岩互层（图2a）。2.0~4.0 m为中厚层灰色砂岩,发育交错层理（图2b）。4.0~7.8 m为灰绿色细砂岩、泥质粉砂岩和粉砂质泥岩互层（图2c）,在粉砂质泥岩中可见菱铁矿结核（图2d）及植物根茎化石（图2e）,砂岩分选性中等,磨圆度为次棱角状（图3c）,是辫状河三角洲沉积环境的产物[15,35]。7.8 m之上有一套厚约4.2 m的黑色页岩,可见带状菱铁矿及透镜状菱铁矿,沉积环境为深湖或半深湖[15,35]。黑色页岩上方出露厚约2.3 m的深灰色粉砂质泥岩夹带状菱铁矿。14.5~17.0 m是一套厚约1.0 m的深灰色泥岩及厚约1.5 m的深灰色粉质泥岩,富含菱铁矿。17.0~23.0 m主要为杂色泥岩与薄层灰白色砂岩互层,夹杂有薄层白色粉砂岩,为浅湖相沉积[15]。23.0~31.0 m主要发育厚层灰白色、灰黄色砂岩,夹有薄层白色粉砂岩,发育水平层理,砂岩的分选和磨圆均较差,呈次棱角状（图3e~i）。25.3 m处发育一套厚约1.2 m的泥岩,为辫状河三角洲相沉积[15,35]。31.0~38.5 m主要发育杂色泥岩夹薄层砂岩,沉积环境为浅湖[15,35]。38.5~47.0 m主要发育紫色泥岩及中厚层灰白色砂岩,夹薄层灰绿色泥岩,其中砂岩分选、磨圆均较差,碎屑颗粒呈棱角状（图3j）,为辫状河三角洲沉积[15]。47.0 m之后发育厚层灰白色砂岩,李昌昊等[15]认为是河流相沉积。前人根据孢粉组合、古地理及沉积环境认为早侏罗世早期是温暖湿润的气候环境,中晚期变成炎热干旱的气候环境[15,36]。

    Figure 2.  Outcrop characteristics of the Fuxian Formation sedimentary profile in the Anya section, northeastern Ordos Basin

    Figure 3.  Microscopic characteristics of sandstone from the Fuxian Formation in the Anya section, northeastern Ordos Basin

    此外,在安崖剖面中下部黑色页岩和泥岩中（10.3~20.0 m,图2）,记录了中生代著名的极热事件之一,即早侏罗世托阿尔期大洋缺氧事件（Toarcian Oceanic Anoxic Event,T-OAE）[33⁃34],这一事件一直是学界关注的焦点。T-OAE时期,由于古生物生产力提高或缺氧,富含有机质的沉积物在全球陆架区广泛沉积[37],还伴随着大气中CO2浓度升高及全球变暖、水循环加速、大陆风化增强、海平面上升、地球表层碳循环紊乱、生物灭绝与更替及湖泊生产力旺盛等现象[33⁃34,38⁃41]。

    综上,前人关于榆林安崖剖面的研究多聚焦于富县组的沉积环境、沉积相以及T-OAE的陆相生物—环境响应等方面[15,33⁃34],对于安崖剖面富县组物源体系还缺少相关研究。

3.   样品采集和分析方法

  • 对安崖剖面进行了实测（图2）,主要是在Jin et al.[33]的野外工作基础上对剖面22.0 m以上部分进行了更加细致的露头踏勘和岩石学描述。对采集的10件新鲜砂岩样品（表1；WY-1、WY00、WY01、WY02、WY03、WY05、WY06、WY07、WY08）进行了岩石学研究,并对其中的6件（WY00、WY01、WY02、WY06、WY07、WY08）进行主微量元素及稀土元素地球化学分析,取样层位及岩性见图2所示。

    样品编号采样层位岩性固结程度
    WY-1J1f灰白色中砂岩固结
    WY00J1f灰白色中砂岩固结
    WY01J1f灰绿色中砂岩固结
    WY02J1f灰白色细砂岩固结
    WY03J1f灰白色细砂岩固结
    WY04J1f灰白色细砂岩固结
    WY05J1f灰黄色细砂岩固结
    WY06J1f灰白色中砂岩固结
    WY07J1f灰白色细砂岩固结
    WY08J1f灰白色中砂岩固结

    • 3.1.   岩石学分析

  • 利用偏光显微镜对已磨制成薄片的10件砂岩样品进行观察并照相,同时采用Gazzi-Dickinson计数法对薄片镜下碎屑进行了分类统计,重矿物和灰岩岩屑不参与计数。粒径大于0.062 5 mm的岩屑颗粒在统计过程中会分解计数,从而降低粒度对成分的影响。该统计方法可以用来反映物源组成并解释构造环境[42⁃43]。该实验在成都理工大学油气藏地质及开发工程国家重点实验室完成。

    • 3.2.   主微量元素分析

  • 首先将样品用锉刀去除表面灰尘和风化部分,再用去离子水冲洗,之后将样品放在恒温55 ℃烤箱中烘干,最后用玛瑙钵研磨至粒径200目以下。样品制备在成都理工大学材料与化学化工学院完成。

    主微量分析采用Thermo Fisher IRIS Advantage型电感耦合等离子光谱（ICP-OES）及Thermo Fisher VG-X7型电感耦合等离子质谱（ICP-MS）测定元素组成,首先将样品用HF+HNO3+HClO4混合酸进行消解,然后使用ICP-OES和ICP-MS进行主、微量元素测定。在微量元素测试过程中,采用10×10-9的Rh元素作为内标来监控仪器的稳定性。在分析过程中,使用国际标准（BHVO-2,W-2a,GSP-2,GSD-9）及空白样品进行监测,检测的数据的相对误差均小于5%。该实验的预处理及测试均在同济大学海洋地质国家重点实验室完成。

4.   样品岩石学特征及测试结果

    4.1.   岩石学特征

  • 10件砂岩样品中石英的含量介于67.5%~79.6%,平均含量73.0%（表2）,其中单晶石英含量较高,约占石英总含量的85.3%；多晶石英约占石英总含量的14.7%,主要为燧石（图3a）、玉髓碎屑（图3b）。长石在研究区砂岩组分中含量较低,含量介于4.3%~10.9%,平均约8.2%（表2）,其中以钾长石为主,发育格子双晶（图3g,i）,斜长石含量较少,发育聚片双晶,少见卡纳复合双晶。岩屑含量介于16.1%~24.3%（表2）,主要为变质岩岩屑及岩浆岩岩屑,见少量沉积岩岩屑,推断其母岩为岩浆岩及变质岩。变质岩岩屑主要为石英岩岩屑（图3i）,约占岩屑总含量52.4%；沉积岩岩屑主要为粉砂岩和泥岩岩屑,约占岩屑总含量7.3%；岩浆岩岩屑主要为凝灰岩岩屑和隐晶质岩岩屑（图3h,j）,约占岩屑总含量40.3%。填隙物主要为碳酸盐灰泥,还有少量绿泥石、重质沥青（图3f）,重矿物主要有锆石（图3n）、绿帘石（图3o）及少量云母碎屑（图3k,l）。部分样品可见自生白云石（图3g,i）,晶形较好,呈菱形。砂岩中的碎屑组分及其含量表明,安崖剖面富县组砂岩类型主要为长石岩屑石英砂岩及岩屑石英砂岩（图4）[44]。

    样品编号总颗粒数石英Q/%长石总量F/%岩屑L/%
    石英总量（Qt）单晶石英（Qm）多晶石英（Qp）岩屑总量沉积岩屑（Ls）岩浆岩屑(Lv）变质岩屑（Lm）
    WY-140873.386.014.08.618.112.235.152.7
    WY0040178.387.912.14.717.08.845.645.6
    WY0139779.684.815.24.316.17.842.250.0
    WY0240070.387.912.110.319.53.841.055.1
    WY0340271.185.015.09.519.47.739.752.6
    WY0440671.983.916.19.618.55.338.756.0
    WY0543275.983.816.25.818.313.936.749.4
    WY0641169.884.315.710.919.22.545.651.9
    WY0739167.582.217.88.224.35.335.858.9
    WY0840271.986.913.110.018.25.542.552.1
    平均值40573.085.314.78.218.87.340.352.4

    Figure 4.  Classification diagram of sandstone composition from the Fuxian Formation in the northeastern Ordos Basin (base map from reference [44])

    • 4.2.   主量元素特征

  • 6件砂岩样品的主量元素组成见表3。测试结果表明富县组砂岩以SiO2和Al2O3两种主量元素为主,其含量之和介于84.67%~92.56%,平均含量为87.94%,SiO2含量介于71.65%~89.34%,平均含量80.82%,均高于上地壳平均值（66.0%）；Al2O3含量介于2.26%~14.34%,平均含量为7.12%,均低于上地壳平均值（15.17%）；CaO含量介于0.10%~5.10%,平均含量为1.72%,绝大多数低于上地壳平均值（4.19%）；Fe2O3含量介于0.94%~5.05%,平均含量为2.43%,绝大多数低于上地壳平均值（4.45%）；K2O含量介于0.52%~2.46%,平均含量为1.42%,均低于上地壳平均值（3.39%）；MgO含量介于0.03%~0.28%,平均含量为0.14%,远低于上地壳平均值（2.2%）；MnO含量介于0.04%~0.12%,平均含量为0.07%,绝大多数低于上地壳平均值（0.07%）；Na2O含量介于0~0.1%,平均含量为0.05%,均低于上地壳平均值（3.89%）；P2O5含量介于0.02%~0.06%,平均含量0.03%,均低于上地壳平均值（0.15%）；TiO2含量介于0.14%~0.58%,平均含量为0.33%,绝大多数低于上地壳平均值（0.5%）。

    样品号SiO2Al2O3CaOFe2O3（T）K2OMgOMnONa2OP2O5TiO2烧失量Al2O3/SiO2K2O+ Na2O
    WY0081.574.055.072.010.520.110.1200.030.246.280.050.52
    WY0189.342.262.110.940.560.030.0800.010.134.540.030.56
    WY0277.477.212.712.681.600.210.070.100.040.457.460.091.70
    WY0683.848.720.101.342.460.100.040.060.040.243.060.102.53
    WY0771.6514.340.195.051.690.280.070.090.060.326.260.201.78
    WY0881.036.180.112.561.700.080.060.030.010.587.650.081.73
    平均值80.827.121.722.431.420.140.070.050.030.335.870.091.47
    注：Fe2O3（T）代表全铁含量。

    砂岩成分成熟度Al2O3/SiO2值介于0.03~0.20,平均为0.09,表明研究区富县组沉积物离物源区较远,砂岩中富SiO2的矿物或石英含量高。K2O+Na2O含量介于0.52%~2.53%,平均含量为1.47%,表明砂岩中富钾和钠的矿物或长石含量较低,同时Na2O含量远低于K2O含量,表明长石以钾长石为主,这与薄片鉴定结果一致。

    WY00、WY01和WY02三件样品的CaO含量明显高于其他三件样品（WY06、WY07和WY08）,表明这三件样品碳酸盐矿物较富集。这与薄片鉴定结果一致,WY00、WY01和WY02三件样品（图3b~d）相比其他三件样品（WY06、WY07和WY08）碳酸盐灰泥充填较多,部分还发育自生白云石。

    • 4.3.   微量元素特征

  • 富县组砂岩样品的微量元素组成见表4。其中Ba元素的含量最高,最高达19 690.78 ug/g,WY01、WY02及WY03这3件样品Ba的含量都比较高。In元素的含量最低,最小值为0.01 ug/g。样品Rb/Sr值介于0.18~0.81,平均值为0.43,多数样品Rb/Sr值大于上地壳的Rb/Sr值（0.26）；样品Zr/Hf值介于21.37~27.25,平均值为25.26,均小于上地壳的Zr/Hf值（36.40）；样品Zr/Th值介于9.77~22.25,平均值为16.60,小于上地壳的Zr/Th值（18.40）；样品Sc/Cr值介于0.17~0.38,平均值为0.31,均大于上地壳的Sc/Cr值（0.15）；样品Ti/Zr值介于17.30~32.24,平均值为23.96,多数大于上地壳的Ti/Zr值（19.90）。利用相应元素的平均上地壳值[45]对样品微量元素数据进行均一化后可以发现（图5a）,大部分微量元素相对于上地壳都亏损,部分样品（WY01、WY02和WY06）的Ba元素含量富集。

    样品号WY00WY01WY02WY06WY07WY08平均值
    Li7.536.448.4810.1121.567.4010.26
    Be0.790.070.310.350.820.430.46
    Sc4.711.755.575.376.095.114.77
    V44.4912.8744.2638.5658.8730.1338.20
    Cr17.125.2014.7816.8636.7913.6017.39
    Co2.622.042.973.025.406.143.70
    Ni6.913.708.235.2013.189.937.86
    Cu6.044.499.625.346.868.326.78
    Zn8.4517.5837.9237.4440.3323.7727.58
    Rb30.9114.5547.7268.2948.7144.9542.52
    Sr38.2980.05215.01193.3998.9885.72118.57
    Y8.875.3913.149.0110.8314.8710.35
    Zr44.9532.58131.6983.1367.22167.6287.86
    Nb5.623.118.424.766.049.516.24
    Mo2.000.741.120.472.110.701.19
    Cd0.050.220.320.100.140.190.17
    In0.060.010.030.030.040.020.03
    Cs1.750.170.751.000.810.630.85
    Ba168.763 380.2819 690.789 336.70468.911 065.075 685.08
    Hf2.101.254.923.372.646.153.41
    Ta0.620.410.940.590.490.670.62
    W1.890.820.920.820.670.730.98
    Tl0.170.110.310.390.300.260.26
    Pb23.7118.5814.0222.9626.7516.5120.42
    Bi0.310.040.050.060.060.050.10
    Th3.931.466.205.616.888.355.40
    U0.820.311.331.193.752.781.70
    Rb/Sr0.810.180.220.350.490.520.43
    Zr/Hf21.3726.0626.7624.6625.4427.2525.26
    Zr/Th11.4522.2521.2514.819.7720.0716.60
    Sc/Cr0.280.340.380.320.170.380.31
    Ti/Zr32.2424.7320.5417.3028.3720.5723.96

    Figure 5.  Trace⁃element UCC spider diagram of the samples[45] (a) and chondrite⁃normalized REE diagram[47] (b) of the Fuxian Formation sandstone in the northeastern Ordos Basin

    微量元素的变化趋势在一定程度上可以反映不同物源间的差异[46]。根据富县组砂岩微量元素/UCC均一化蛛网图（图5a）可以发现,除极个别元素外,研究区砂岩样品微量元素/UCC变化趋势较一致,微量元素组成也相似,说明研究区富县组砂岩的物源来自同一物源区。

    • 4.4.   稀土元素特征

  • 富县组砂岩稀土元素测试结果见表5,结果显示研究区砂岩样品富集轻稀土元素（LREE）,而重稀土元素（HREE）较亏损。样品的∑REE含量介于43.92~176.84 μg/g,平均值为107.54 μg/g；∑LREE含量介于39.18~162.14 μg/g,平均值为98.02 μg/g；∑HREE含量介于4.74~14.70 μg/g,平均值为9.52 μg/g；∑LREE/∑HREE介于7.39~12.22,平均为9.84。根据Boynton[47]的球粒陨石稀土元素（REE）数据对研究区6件砂岩样品的稀土元素进行标准化（图5b）[47],发现其稀土元素分配模式整体表现为“缓右倾斜”的样式,呈平坦型分布；WY01、WY02及WY06的Eu含量正异常,其他样品的Eu轻微亏损。

    样号LaCePrNdSmEuGdTbDyHoErTmYbLuREELREEHREE
    WY009.3020.962.6110.722.370.672.490.351.600.280.790.100.620.0952.9446.636.31
    WY017.7518.192.078.111.731.341.940.261.190.200.570.070.450.0743.9239.184.74
    WY0224.1851.946.0122.624.004.134.610.532.520.471.540.211.340.19124.29112.8811.41
    WY0619.5139.104.6817.092.942.183.420.391.760.351.130.151.010.1693.8885.518.37
    WY0729.8770.827.1727.754.761.425.230.572.360.431.410.181.240.18153.37141.7711.60
    WY0835.0978.648.5832.635.671.536.390.733.170.581.870.231.510.23176.84162.1414.70
    平均值20.9546.615.1919.823.581.884.010.472.100.391.220.161.030.15107.5498.029.52
5.   讨论

    5.1.   源区岩性判别

  • 由于Th、Sc、Co、Zr、Hf、Nb等微量元素和稀土元素的化学性质极不活泼,这些元素一般稳定赋存于沉积物,在母岩风化、剥蚀、搬运、沉积及成岩的过程中含量几乎不发生变化,因此也可以用来反映物源区的特征[3,48⁃49]。Allègre et al.[50]在1978年提出的La/Yb-∑REE判别图解可以用来很好地反映岩石成因特征,因此该方法在物源分析中被广泛应用。依据La/Yb-∑REE判别图解,安崖剖面富县组下部的WY00样品投在花岗岩及沉积岩钙质泥岩重叠区域,WY01投在沉积岩钙质泥岩区域,其他样品均投在花岗岩区域（图6a）[50],表明富县组物源较单一,母岩可能为花岗岩类,但是富县组早期有克拉通内部的沉积岩物质混入,可能是延长组顶部长石砂岩的风化物质[21]。此外,Floyd et al.[49]根据稳定微量元素的含量及比值特征,提出利用Hf-La/Th图解判别不同源区的构造环境。基于此方法,大部分砂岩样品投在长英质及长英质、基性混合物源区（图6b）[49],表明富县组砂岩的源岩主要来自上地壳,并有少量基性岩浆岩等火山弧物质混入。

    Figure 6.  Discrimination diagrams of the Fuxian Formation sandstones in the northeastern Ordos Basin

    Gu et al.[51]建立的Co/Th-La/Sc图解也可以用来判别不同的沉积物源和弧成分,Co/Th-La/Sc图解显示（图6c）[51⁃52],研究区所有样品位于“长英质”组分与“花岗岩”组分之间,与La/Yb-∑REE图解判别的“花岗岩”及Hf-La/Th图解判别的“长英质及长英质、基性混合物源区”基本吻合。综合La/Yb-∑REE、Hf-La/Th及Co/Th-La/Sc图解判断显示,富县组沉积物来自同一物源体系,结合岩屑特征显示出富县组沉积物的源岩具有变质岩及岩浆岩的性质,可以推断研究区富县组沉积物的母岩主要为中酸性岩浆岩及变质岩。

    • 5.2.   源区构造背景判别

  • 自20世纪70年代开始,Dickinson三角图解已成为物源分析中最常用的方法,它可以明晰母岩的性质及其构造背景[42,53⁃54]。

    Dickinson et al.[53⁃54]通过对北美地区一万多个砂岩样品统计分析,系统性总结出砂岩碎屑组分与物源区、沉积盆地构造背景之间的关系,并划分了稳定克拉通或隆起基底、再旋回造山带及火山弧物源区等3个板块构造环境,又细分了7个次级物源区,建立的Q-F-L、Qm-F-Lt、Qt-F-L、Qp-Lv-Ls和Qm-P-K等5种子模式判别图用于判别砂岩的成熟度、源岩性质、岩屑含量和各矿物的相对含量。自Dickinson三角图解提出以来,陆续有其他学者对Dickinson三角图解的各个构造边界进行优化计算,使得这种方法日臻完善[55⁃56]。基于Dickinson图解,对10件砂岩样品的碎屑组分进行Qt-F-L、Qm-F-Lt投图（图7）[42,54⁃56]。研究区所有样品均投在Qt-F-L图再旋回造山带区域（图7a）；此外,Qm-F-Lt图上所有样品也均在再旋回造山带区域（图7b）。由此推断,鄂尔多斯东北部富县组沉积时期具有单一的物源,整个富县组沉积均是同一物源体系下的产物；鄂尔多斯富县组沉积物物源区构造环境以再旋回造山带为主,具有构造活动较强烈的构造背景。

    Figure 7.  Dickinson diagram for sandstone components from the Fuxian Formation (base map from references [42,54⁃56])

    • 5.3.   周缘潜在物源区对比

  • 前人研究认为,自晚古生代中晚期以来,鄂尔多斯盆地南、北两侧造山带（古陆）均已成为沉积物源区（阴山造山带、秦岭造山带）。晚石炭世—二叠纪时期,鄂尔多斯地区呈南北隆起、中部坳陷的古地理格局,盆地内石炭系—二叠系主要物源来自北缘的内蒙古陆以及南缘的祁连一秦岭古陆[57]。晚三叠世末的印支运动导致位于华北板块西部的鄂尔多斯盆地整体抬升、剥蚀,形成三叠系顶部以沟谷纵横、丘陵起伏为特征的地貌景观[23]。侏罗纪早期继承了晚古生代中晚期盆地南、北古陆物源区特点,同时盆地西北缘和西缘地区也一并成为沉积物源区（阿拉善地块、祁连造山带）。由此可知,盆地周缘潜在的物源区有盆地北侧的阴山造山带、盆地南侧和西南侧的祁连—秦岭造山带（或陇西古陆）以及盆地西北侧的阿拉善地块（图1c）。

    稀土元素因其特殊的化学性质,在物源示踪方面得到广泛的应用[2,50]。将研究区稀土元素地球化学特征与潜在源区进行对比,可以比较明确地判定沉积岩的源区[44]。总结了前人在阿拉善古陆、阴山造山带、陇西古陆及秦岭造山带获得的稀土元素研究数据,利用Boynton[47]的球粒陨石稀土元素数据对相关砂岩数据进行标准化处理后,得到了盆地周缘多个潜在源区岩石样品的稀土元素（REE）分配模式图（图8）[31,44,58⁃59]。其中阴山造山带和阿拉善古陆源岩的稀土元素分配模式较为相似,均表现为整体向右缓倾,重稀土元素（HREE）较平坦,但是阴山造山带δEu轻微亏损,而阿拉善古陆部分因δEu亏损严重而表现为深V字形（图8a,b）；陇西古陆砂岩的分配模式总体比较平缓,没有明显亏损或者富集（图8c）；秦岭造山带砂岩的分配模式因δEu严重亏损而表现为深V字形,HREE呈平坦型分布（图8d）。

    Figure 8.  REE patterns of potential source areas around the study area（modified from reference [44]）

    安崖剖面富县组WY01、WY02及WY03砂岩样品δEu富集,WY06、WY07及WY08砂岩样品δEu轻微亏损,而δEu富集的三件样品,其Ba元素含量高（最高达19 690.78 μg/g）（图5a）。研究表明,Ba元素含量较高的岩石样品在使用ICP-MS测定稀土元素时,由于Ba的氧化物及氢氧化物会对Eu元素的质谱峰产生重叠干扰,从而使Eu含量偏高[60]。另外,有研究发现Ba元素的含量或聚集速率与生物生产力之间具有良好的正相关性[61⁃62],即当生物生产力强的时候,环境中Ba元素的含量往往很高。而在早侏罗世托阿尔期大洋缺氧事件（T-OAE）时期,湖泊生产力较高[37,63],进而促进了岩石样品中Ba元素的聚集。因此,测试样品中Eu含量正异常可能受到高Ba元素含量的影响,而与物源区的变化无关；此外,研究区周缘潜在物源区的δEu均表现为亏损,也证明研究区Eu含量异常与源区无关（图8）。研究区稀土元素整体表现为“缓右倾斜”的样式,整体呈平坦型分布（图5b）,这与鄂尔多斯盆地北侧的阴山造山带的稀土元素整体特征较一致,表明安崖剖面富县组砂岩的物源区应该为盆地北侧的阴山造山带。

    研究也支持了前人关于阴山造山带演化的观点,古亚洲洋在泥盆纪早期开始向南部的华北陆块俯冲,发生了陆—陆点式碰撞[64]。晚石炭世—中二叠世,由于古亚洲洋持续向南俯冲,导致华北陆块北缘开始隆升,古阴山褶皱造山带开始形成,大量的花岗岩浆侵入形成大规模的花岗岩体[65]。此时,鄂尔多斯盆地已经结束隆升剥蚀状态,盆地北缘的沉积物开始在盆地沉积。至二叠世末期,由于蒙古陆块与华北陆块开始碰撞拼合,古亚洲洋完全消亡[66⁃67]。早三叠世,蒙古陆块与华北陆块碰撞结束后,盆地内的物源由碰撞形成的造山带持续供给。至中晚三叠世,古亚洲洋板块俯冲形成的洋壳根部发生断裂拆离,软流圈和幔源物质上涌,导致基性岩浆岩熔融了早期的古老基底,造成中大规模的晚三叠世花岗岩侵入体[68],而阴山造山带在经历了多次构造演化后,具有再旋回造山的性质。早—中侏罗世,华北陆块北部的造山作用较弱,使得阴山造山带中三叠纪形成的花岗岩及古老的变质结晶基底逐渐被风化剥蚀,风化产物被晋陕古河搬运到鄂尔多斯盆地东北部沉积（图9）[15,29,69⁃70]。前人在研究区东北部府谷县的古水流分析指示富县组时期古流向为北南向[70],与此次研究的结论吻合。

    Figure 9.  Provenance system model of the Early Jurassic Fuxian Formation in the northeastern Ordos Basin (modified from references [15,29,69]; palaeocurrent data from reference [70])

6.   结论

  • （1） 安崖剖面富县组砂岩样品的岩石学特征、主微量及稀土元素特征显示物源具有相似性；利用La/Yb-∑REE、Hf-La/Th及Co/Th-La/Sc图解结合砂岩镜下特征综合判断,富县组砂岩的母岩为中酸性岩浆岩及变质岩；Qm-F-Lt和Qt-F-L三角图解显示富县组物源区构造环境为再旋回造山带。

    （2） 研究区稀土元素分配整体表现为“缓右倾斜”的样式,整体呈平坦型分布,与周缘潜在源区源岩稀土元素分配模式对比发现,研究区稀土元素整体特征与阴山造山带一致,结合阴山造山带的演化史,认为富县组沉积时期盆地东北部的主物源区为盆地北缘的阴山造山带。

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