Advanced Search

Indexed by SCI、CA、РЖ、PA、CSA、ZR、etc .

Volume 31 Issue 1
Jan.  2020
Turn off MathJax
Article Contents

Shuang Liu, Zuoyu Sun, Cheng Ji, Min Zhou, Dayong Jiang. Conodont Biostratigraphy and Age of the Early Triassic Fish-Bearing-Nodule Levels from Nanjing and Jurong, Jiangsu Province, South China. Journal of Earth Science, 2020, 31(1): 9-22. doi: 10.1007/s12583-019-1232-y
Citation: Shuang Liu, Zuoyu Sun, Cheng Ji, Min Zhou, Dayong Jiang. Conodont Biostratigraphy and Age of the Early Triassic Fish-Bearing-Nodule Levels from Nanjing and Jurong, Jiangsu Province, South China. Journal of Earth Science, 2020, 31(1): 9-22. doi: 10.1007/s12583-019-1232-y

Conodont Biostratigraphy and Age of the Early Triassic Fish-Bearing-Nodule Levels from Nanjing and Jurong, Jiangsu Province, South China

doi: 10.1007/s12583-019-1232-y
More Information
  • Fish-bearing-nodules are found in Early Triassic marine strata in many regions, including East Greenland, East Spitsbergen, Northwest Madagascar, Canada, Angola, and South China. A new Olenekian (Early Triassic) conodont biostratigraphic study for stratum that contains fish-bearing-nodule levels is conducted based on the Longtan (LT) Section of Nanjing City and the Qingshan (QS) Section of Jurong County, Jiangsu Province, South China. A total of 101 samples were collected at the two sections and three conodont zones were recognized:in ascending order, they are Scythogondolella (Sc.) milleri Zone, Novispathodus (Nv.) pingdingshanensis Zone, and Triassospathodus (Tr.) aff. homeri Zone. The Scythogondolella milleri Zone is globally recognized as the uppermost conodont zone of the Smithian and the base of the Novispathodus pingdingshanensis Zone was previously suggested as the marker of the Smithian-Spathian boundary in the Yangtze region. The fish-bearing-nodule levels of Nanjing and Jurong are within the conodont Scythogondolella milleri Zone, laterally correlated well with the upper part of the Novispathodus waageni Zone in Chaohu of Anhui Province that also contains fish-bearing-nodule levels. The conodont biostratigraphic correlation confirms the Early Triassic fish-bearing-nodule levels in the Lower Yangtze region are coeval, with an end-Smithian in age.
  • 加载中
  • Bender, H., 1970. Zur Gliederung der Mediterranen Trias Ⅱ. Die Conodontenchronologie der Mediterranen Trias. Annales Géologiques des Pays Helléniques, 19: 465-540 (in French)
    Chen, C. Z., Wang, Y. G., Wang, Z. H., et al., 1988. Triassic Biostratigraphy in Southern Jiangsu Province. In: Academy of Geological Sciences, Jiangsu Bureau of Petroleum, Prospecting and Nanjing Institute of Geology and Paleontology, Academia Sinica Sinian-Triassic Biostratigraphy of the Lower Yangtze Peneplatform in Jiangsu Region. Nanjing University Press, Nanjing (in Chinese)
    Chen, M. J., 1996. Conodonts of Upper Permian-Lower Triassic of Zhenjiang Area. Acta Palaeontologica Sinica, 35: 430-441 (in Chinese with English Abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK199600128564
    Chen, Y. L., Jiang, H. S., Lai, X. L., et al., 2015. Early Triassic Conodonts of Jiarong, Nanpanjiang Basin, Southern Guizhou Province, South China. Journal of Asian Earth Sciences, 105: 104-121. https://doi.org/10.1016/j.jseaes.2015.03.014 doi:  10.1016/j.jseaes.2015.03.014
    Chen, Y. L., Kolar-Jurkovšek, T., Jurkovšek, B., et al., 2016. Early Triassic Conodonts and Carbonate Carbon Isotope Record of the Idrija-Žiri Area, Slovenia. Palaeogeography, Palaeoclimatology, Palaeoecology, 444: 84-100. https://doi.org/10.13039/501100004329 doi:  10.13039/501100004329
    Chhabra, N. L., Kumar, S., 1992. Late Scythian through Early Carnian Conodont Assemblages and Their Biostratigraphic Significance from off Shore Carbonates of Northern Kumaun, Tethys Himalaya, India. Revue de Micropaleontologie, 35: 3-21
    Chhabra, N. L., Sahni, A., 1981. Late Lower Triassic and Early Triassic Conodont Faunas from Kashmir and Kumaun Sequences in Himalaya. Journal of the Palaeontological Society of India, 25: 47-135
    Clark, D. L., 1959. Conodonts from the Triassic of Nevada and Utah. Journal of Paleontology, 33: 305-312
    Fang, Q., Zhang, H. J., Wang, X. L., et al., 2015. The Discovery of Early Triassic Conodont in the Huashixia Area of Maduo County, Qinghai Province, NW China and Its Significance. Acta Micropalaeontologica Sinica, 30: 423-425, 441 (in Chinese with English Abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=wtgswxb201304009
    Feng, Z. Z., Bao, Z. D., Li, S. W., 1997. Lithofaceies Paleogeography of Early and Middle Triassic of South China. Petroleum Industry Press, Beijing (in Chinese)
    Friedman, M., 2015. The Early Evolution of Ray-Finned Fishes. Palaeontology, 58(2): 213-228. https://doi.org/10.13039/501100004789 doi:  10.13039/501100004789
    Fuchs, G., Mostler, H., 1969. Mikrofaunen aus der Tibet-Zone, Himalaya. Verhandlungen der Geologischen Bundesanstalt, 133-145
    Gaetani, M., Jacobshagen, V., Nicora, A., et al., 1992. The Early-Middle Triassic Boundary at Chios (Greece). Rivista Italiana di Paleontologia e Stratigrafia, 98: 181-204 http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=HighWire000006031555
    Henderson, C., 1997. Uppermost Permian Conodonts and the Permian-Triassic Boundary in the Western Canada Sedimentary Basin. Bulletin of Canadian Petroleum Geology, 45: 693-707
    Ji, W. T., Tong, J. N., Zhao, L. S., et al., 2011. Lower-Middle Triassic Conodont Biostratigraphy of the Qingyan Section, Guizhou Province, Southwest China. Palaeogeography, Palaeoclimatology, Palaeoecology, 308(1/2): 213-223. https://doi.org/10.1016/j.palaeo.2010.08.020 doi:  10.1016/j.palaeo.2010.08.020
    Jiang, W., Luo, Y. Q., Lu, T. Q., et al., 2000. The Lower Triassic Conodonts and Its Significance to Oil and Gas Exploration in Sichuan Basin. Acta Micropalaeontology Sinica, 17: 99-109 http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=wtgswxb200001010
    Jin, F., 2006. An Overview of Triassic Fishes from China. Vertebrata PalAsiatica, 44: 28-42 (in Chinese with English Abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=gjzdwxb200601002
    Jin, F., Wang, N. Z., Cai, Z. Q., 2003. A Revision of the Perleidid Fishes from the Lower Yangtze Region of South China. Vertebrata PalAsiatica, 7: 169-84 (in Chinese with English Abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=gjzdwxb200303001
    Kogan, I., Romano, C., 2016. Redescription of Saurichthys Madagascariensis Piveteau, 1945 (Actinopterygii, Early Triassic), with Implications for the Early Saurichthyid Morphotype. Journal of Vertebrate Paleontology, 36(4): e1151886. https://doi.org/10.1080/02724634.2016.1151886 doi:  10.1080/02724634.2016.1151886
    Komatsu, T., Takashima, R., Shigeta, Y., et al., 2016. Carbon Isotopic Excursions and Detailed Ammonoid and Conodont Biostratigraphies around Smithian-Spathian Boundary in the Bac Thuy Formation, Vietnam. Palaeogeography, Palaeoclimatology, Palaeoecology, 454: 65-74. https://doi.org/10.13039/501100001691 doi:  10.13039/501100001691
    Kozur, H., 2003. Integrated Ammonoid, Conodont and Radiolarian Zonation of the Triassic and Some Remarks to Stage/Substage Subdivision and the Numeric Age of the Triassic Stages. Albertiana, 28: 57-74
    Krystyn, L., 2005. A Revised Lower Triassic Intercalibrated Ammonoid-Conodont Time Scale of the Eastern Tethys Realm Based on Himalayan Data. Albertiana, 33: 53-54
    Krystyn, L., Bhargava, O. N., Richoz, S., 2007. A Candidate GSSP for the Base of the Olenekian Stage: Mud at Pin Valley; District Lahul and Spiti, Himachal Pradesh (Western Himalaya), India. Albertiana, 35: 4-29
    Leu, M., Bucher, H., Goudemand, N., 2018. Clade-Dependent Size Response of Conodonts to Environmental Changes during the Late Smithian Extinction. Earth-Science Reviews. https://doi.org/10.1016/j.earscirev.2018.11.003
    Li, Q. G., 2009. A New Parasemionotid-Like Fish from the Lower Triassic of Jurong, Jiangsu Province, South China. Palaeontology, 52(2): 369-384. https://doi.org/10.1111/j.1475-4983.2009.00848.x doi:  10.1111/j.1475-4983.2009.00848.x
    Liang, D., Tong, J. N., Zhao, L. S., 2011. Lower Triassic Smithian-Spathian Boundary at West Pingdingshan Section in Chaohu, Anhui Province. Science China Earth Sciences, 54(3): 372-379. https://doi.org/10.1007/s11430-010-4145-2 doi:  10.1007/s11430-010-4145-2
    Liang, L., Tong, J. N., Song, H. J., et al., 2016. Lower-Middle Triassic Conodont Biostratigraphy of the Mingtang Section, Nanpanjiang Basin, South China. Palaeogeography, Palaeoclimatology, Palaeoecology, 459: 381-393. https://doi.org/10.1016/j.palaeo.2016.07.027 doi:  10.1016/j.palaeo.2016.07.027
    Liu, G. B., Feng, H. Z., Wang, J. X., et al., 2002. Early Triassic Fishes from Jurong, Jiangsu. Acta Paleontologica Sinica, 41: 27-52 (in Chinese with English Abstract) http://d.old.wanfangdata.com.cn/Periodical/gswxb200201005
    Marramà, G., Lombardo, C., Tintori, A., Carnevale, G., 2017. Redescription of 'Perleidus' (Osteichthyes, Actinopterygii) from the Early Triassic of Northwestern Madagascar. Rivista Italiana di Paleontologia e Stratigrafia, 123(2): 219-242 http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=ddf28e1da5a5656a708f2705c9bcfd3c
    Mosher, L. C., 1973. Triassic Conodonts from British Columbia and the Northern Arctic Islands. Bulletin of the Geological Survey of Canada, 222: 141-192
    Müller, K. J., 1956. Triassic Conodonts from Nevada. Journal of Paleontology, 30: 818-830 http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=3588c9912751fb6e90a61c452dcf55bf
    Nakrem, H. A., Orchard, M. J., Weitschat, W., et al., 2008. Triassic Conodonts from Svalbard and Their Boreal Correlations. Polar Research, 27(3): 523-539. https://doi.org/10.3402/polar.v27i3.6190 doi:  10.3402/polar.v27i3.6190
    Nogami, Y., 1968. Trias-Conodonten von Timor, Malaysien und Japan. Memoirs of the Faculty of Science, Kyoto University, 34: 115-136
    Orchard, M. J., 1995. Taxonomy and Correlation of Lower Triassic (Spathian) Segminate Conodonts from Oman and Revision of Some Species of Neospathodus. Journal of Paleontology, 69(1): 110-122. https://doi.org/10.1017/s0022336000026962 doi:  10.1017/s0022336000026962
    Orchard, M. J., 2008. Lower Triassic Conodonts from the Canadian Arctic, Their Intercalibration with Ammonoid-Based Stages and a Comparison with Other North American Olenekian Faunas. Polar Research, 27(3): 393-412.https://doi.org/10.3402/polar.v27i3.6187 doi:  10.3402/polar.v27i3.6187
    Orchard, M. J., Tozer, E. T., 1997. Triassic Conodont Biochronology, Its Calibration with the Ammonoid Standard, and a Biostratigraphic Summary for the Western Canada Sedimentary Basin. Bulletin of Canadian Petroleum Geology, 45(4): 675-692
    Orchard, M. J., Zonneveld, J. P., et al., 2009. The Lower Triassic Sulphur Mountain Formation in the Wapiti Lake Area: Lithostratigraphy, Conodont Biostratigraphy, and a New Biozonation for the Lower Olenekian (Smithian) Earth Science Sector (ESS) Contribution 20080714. Canadian Journal of Earth Sciences, 46(10): 757-790. https://doi.org/10.1139/e09-051 doi:  10.1139/e09-051
    Orchard, M. J., Lehrmann, D. J., Wei, J., et al., 2007a. Conodont from the Olenekian-Anisian Boundary Beds, Guandao, Guizhou Province, China. In: Lucas, S. G., Spielmann, J. A. eds., The Global Triassic. New Mexico Museum of Natural History and Science Bulletin, 41: 347-354
    Orchard, M. J., Gradinaru, E., Nicora, A., 2007b. A Summary of the Conodont Succession around the Olenekian-Anisian Boundary at Desli Caira, North Dobrogea, Romania. In: Lucas, S. G., Spielmann, J. A., eds., The Global Triassic. New Mexico Museum of Natural History and Science Bulletin, 41: 341-346
    Qian, M. P., Zhu, S. P., Zhao, F. M., et al., 1997. Discovery of Early Triassic Fish Fossils and Its Significances in Jurong, Jiangsu Province. Jiangsu Geology, 21: 65-71 (in Chinese with English Abstract)
    Romano, C., Koot, M. B., Kogan, I., et al., 2014. Permian-Triassic Osteichthyes (Bony Fishes): Diversity Dynamics and Body Size Evolution. Biological Reviews, 91(1): 106-147. https://doi.org/10.13039/501100001711 doi:  10.13039/501100001711
    Scheyer, T. M., Romano, C., Jenks, J., et al., 2014. Early Triassic Marine Biotic Recovery: The Predators' Perspective. Plos ONE, 9(3): e88987. https://doi.org/10.1371/journal.pone.0088987 doi:  10.1371/journal.pone.0088987
    Solien, M. A., 1979. Conodont Biostratigraphy of the Lower Triassic Thaynes Formation, Utah. Journal of Paleontology, 53: 276-306
    Su, D. Z., 1981. A New Species of Perleidus from Anhui. Vertebrata PalAsiatica, 19(2): 107-112 (in Chinese with English Abstract)
    Sweet, W. C., 1970. Uppermost Permian and Lower Triassic Conodonts of the Salt Range and Trans-Indus Ranges, West Pakistan. In: Kummel, B., Teichert, C., eds., Stratigraphic Boundarty Problems: Permian and Triassic of West Pakistan. University of Kansas, Department of Geology, Special Publication, 4: 207-275
    Sweet, W. C., Mosher, L. C., Clark, D. L., 1971. Conodont Biostratigraphy of the Triassic. Geological Society of America Memoir, 127: 441-465 doi:  10.1016-S1367-9120(02)00021-4/
    Tian, C. R., 1982. Triassic Conodonts in the Tulong Section from Nyalam County, Xizang (Tibet), China. Geological Review, 3: 153-165 (in Chinese with English Abstract)
    Tintori, A., Hitij, T., Jiang, D. Y., et al., 2014. Triassic Actinopterygian Fishes: The Recovery after the End-Permian Crisis. Integrative Zoology, 9(4): 394-411. https://doi.org/10.1111/1749-4877.12077 doi:  10.1111/1749-4877.12077
    Tong, J. N., Zakharov, Y. D., Wu, S. B., 2004. Early Triassic Ammonoid Succession in Chaohu, Anhui Provinve. Acta Palaeontologica Sinica, 43: 192-204 (in Chinese with English Abstract)
    Tong, J. N., Zhou, X. G., Erwin, D. H., et al., 2006. Fossil Fishes from the Lower Triassic of Majiashan, Chaohu, Anhui Province, China. Journal of Paleontology, 80(1): 146-161. https://doi.org/10.1666/0022-3360(2006)080[0146:ffftlt]2.0.co; 2 doi:  10.1666/0022-3360(2006)080[0146:ffftlt]2.0.co;2
    Wang, H. M., Wang, X. L., Li, R. X., et al., 2005. Triassic Conodont Succession and Stage Subdivision of the Guandao Section, Bianyang, Luodian, Guizhou. Acta Palaeontologica Sinica, 44(4): 611-626 (in Chinese with English Abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=gswxb200504012
    Wang, H. Z., Shi, X. Y., Wang, X. L., et al., 2000. Research on the Sequence Stratigraphy of China. Guangdong Science and Technology Press, Guangzhou. 457 (in Chinese with English Abstract)
    Wang, Z. H., Cao, Y. Y., 1981. Early Triassic Conodonts from Lichuan, Western Hubei. Acta Micropalaeontology Sinica, 20: 363-375 (in Chinese with English Abstract) http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=9763e2d3290c15cb61cd577eccfe60c3
    Wang, Z. H., Zhong, D., 1994. Triassic Conodonts from Different Facies in Eastern Yunnan, Western Guizhou and Northern Guangxi. Acta Micropalaeontologica Sinica, 11: 379-412 (in Chinese with English Abstract)
    Wu, G. C., Yao, J. X., Ji, Z. S., 2007. Triassic Conodont Biostratigraphy in the Coqen Area, Western Gangdise, Tibet, China. Geological Bulletin of China, 26: 938-946 (in Chinese with English Abstract)
    Yan, C. B., Wang, L. N., Jiang, H. S., 2013. Uppermost Permian to Lower Triassic Conodonts at Bianyang Section, Guizhou Province, South China. Palaios, 28(8): 509-522. https://doi.org/10.2110/palo.2012.p12-077r doi:  10.2110/palo.2012.p12-077r
    Yang, S. R., Chu, Q. C., 1992. Study on Conodonts from Triassic Yongningzhen Formation, Southwestern Guizhou Province with a Discussion on Lower/Middle Triassic Boundary. Acta Scientiarum Naturalium Universitatis Pekinensis, 28: 723-732 (in Chinese with English Abstract)
    Zhao, L. S., Chen, Y. L., Chen, Z. Q., et al., 2013. Uppermost Permian to Lower Triassic Conodont Zonation from Three Gorges Area, South China. Palaios, 28(8): 523-540. https://doi.org/10.2110/palo.2012.p12-107r doi:  10.2110/palo.2012.p12-107r
    Zhao, L. S., Orchard, M. J., 2007. Lower Triassic Conodont Sequence in Chaohu, Anhui Province, China and Its Global Correlation. Paleogeography, Palaeoclimatology, Palaeoecology, 252: 24-38. https://doi.org/10.1016/j.palaeo.2006.11.032 doi:  10.1016/j.palaeo.2006.11.032
    Zhao, L. S., Orchard, M. J., Tong, J. N., et al., 2007. Lower Triassic Conodont Sequence in Chaohu, Anhui Province, China and Its Global Correlation. Palaeogeography, Palaeoclimatology, Palaeoecology, 252(1/2): 24-38. https://doi.org/10.1016/j.palaeo.2006.11.032 doi:  10.1016/j.palaeo.2006.11.032
    Zhao, L. S., Tong, J. N., Sun, Z. M., et al., 2008. A Detailed Lower Triassic Conodont Biostratigraphy and Its Implications for the GSSP Candidate of the Induan-Olenekian Boundary in Chaohu, Anhui Province. Progress in Natural Science, 18(1): 79-90. https://doi.org/10.1016/j.pnsc.2007.07.001 doi:  10.1016/j.pnsc.2007.07.001
    Zhang, L., Orchard, M. J., Brayard, A., et al., 2019. The Smithian-Spathian Boundary (Late Early Triassic): A Review of Ammonoid, Conodont, and Carbon-Isotopic Criteria. Earth-Science Reviews. https://doi.org/10.13039/501100004701
    Zuo, J. X., Tong, J. N., Qiu, H. O., et al., 2006. Carbon Isotope Composition of the Lower Triassic Marine Carbonates, Lower Yangtze Region, South China. Science in China Series D: Earth Science, 49(3): 225-241. https://doi.org/10.1007/s11430-006-0225-8 doi:  10.1007/s11430-006-0225-8
  • 加载中
通讯作者: 陈斌, bchen63@163.com
  • 1. 

    沈阳化工大学材料科学与工程学院 沈阳 110142

  1. 本站搜索
  2. 百度学术搜索
  3. 万方数据库搜索
  4. CNKI搜索

Figures(7)  / Tables(1)

Article Metrics

Article views(163) PDF downloads(26) Cited by()

Related
Proportional views

Conodont Biostratigraphy and Age of the Early Triassic Fish-Bearing-Nodule Levels from Nanjing and Jurong, Jiangsu Province, South China

doi: 10.1007/s12583-019-1232-y
    Corresponding author: Zuoyu Sun

Abstract: Fish-bearing-nodules are found in Early Triassic marine strata in many regions, including East Greenland, East Spitsbergen, Northwest Madagascar, Canada, Angola, and South China. A new Olenekian (Early Triassic) conodont biostratigraphic study for stratum that contains fish-bearing-nodule levels is conducted based on the Longtan (LT) Section of Nanjing City and the Qingshan (QS) Section of Jurong County, Jiangsu Province, South China. A total of 101 samples were collected at the two sections and three conodont zones were recognized:in ascending order, they are Scythogondolella (Sc.) milleri Zone, Novispathodus (Nv.) pingdingshanensis Zone, and Triassospathodus (Tr.) aff. homeri Zone. The Scythogondolella milleri Zone is globally recognized as the uppermost conodont zone of the Smithian and the base of the Novispathodus pingdingshanensis Zone was previously suggested as the marker of the Smithian-Spathian boundary in the Yangtze region. The fish-bearing-nodule levels of Nanjing and Jurong are within the conodont Scythogondolella milleri Zone, laterally correlated well with the upper part of the Novispathodus waageni Zone in Chaohu of Anhui Province that also contains fish-bearing-nodule levels. The conodont biostratigraphic correlation confirms the Early Triassic fish-bearing-nodule levels in the Lower Yangtze region are coeval, with an end-Smithian in age.

Shuang Liu, Zuoyu Sun, Cheng Ji, Min Zhou, Dayong Jiang. Conodont Biostratigraphy and Age of the Early Triassic Fish-Bearing-Nodule Levels from Nanjing and Jurong, Jiangsu Province, South China. Journal of Earth Science, 2020, 31(1): 9-22. doi: 10.1007/s12583-019-1232-y
Citation: Shuang Liu, Zuoyu Sun, Cheng Ji, Min Zhou, Dayong Jiang. Conodont Biostratigraphy and Age of the Early Triassic Fish-Bearing-Nodule Levels from Nanjing and Jurong, Jiangsu Province, South China. Journal of Earth Science, 2020, 31(1): 9-22. doi: 10.1007/s12583-019-1232-y
  • With rich, well-preserved and complete fish fossils found in carbonate nodules, the Early Triassic 'nodular fish levels' within the Lower Yangtze region, South China have been studied by many authors (Li, 2009; Jin, 2006; Tong et al., 2006; Jin et al., 2003; Liu et al., 2002; Qian et al., 1997; Su, 1981). These levels have been considered approximately early Early Triassic in age because fish assemblages similar to what is yielded by these levels are known globally at that time. However, the biostratigraphic positions of these levels have not been established based on index fossils. These Early Triassic fish-bearing-nodule levels presented a typical peri-Pangean distribution, having been recorded from East Greenland, East Spitsbergen, Northwest Madagascar, Canada, Angola, and South China (Marramà et al., 2017 and references therein). Outside South China, these fish-bearing-nodule levels are potentially synchronous, located closely to the Dienerian/Smithian boundary in most cases, while they were reported from the Griesbachian (Early Induan) in East Greenland, and Dienerian or Smithian in Madagascar (see details in Tintori et al., 2014). The fish fossils from these Early Triassic nodular levels are characteristic of the Triassic Early Fish Fauna (TEFF, Tintori et al., 2014), and will help to understand the Triassic evolutionary history of actinopterygians (Romano et al., 2014; Friedman, 2015) and the trophic recovery of the ecosystems after the end-Permian mass extinction (Kogan and Romano, 2016; Scheyer et al., 2014).

    In South China, the Early Triassic fish-bearing-nodule levels have been found in Chaohu of Anhui Province, Nanjing and Jurong of Jiangsu Province, and in Zhejiang Province in the Lower Yangtze region (Fig. 1a). Abundant perleidids, parasemionotids, and coelacanths were reported from these levels (Li, 2009; Jin, 2006; Tong et al., 2006; Jin et al., 2003; Liu et al., 2002). In Chaohu of Anhui Province, the fish level outcropped at the Majiashan quarry, close to the top of the Helongshan Formation, within the upper part of the conodont Novispathodus waageni Zone, suggesting an age of end-Smithian (Liang et al., 2011; Zhao et al., 2008; Zhao and Orchard, 2007; Tong et al., 2006). In Nanjing and Jurong of Jiangsu Province, these nodular fish levels are in the upper part of the Lower Qinglong Formation, but previously suggested stratigraphic level is no more precise than Olenekian (Early Triassic) (Wang et al., 2000; Chen et al., 1988). So far, it is unclear if these levels can be correlated with that in Chaohu of Anhui Province. In this paper, we carried out detailed research on conodont biostratigraphy of the upper part of Lower Qinglong Formation containing the fish-bearing-nodule levels at Longtan Section of Nanjing City and Qingshan Section of Jurong County, Jiangsu Province (Fig. 1b), aiming to clarify its age and correlation with that in Chaohu of Anhui Province.

    Figure 1.  (a) The Early Triassic paleogeographic map of South China showing the paleogeographic setting of the Jiangsu area during that time (modified from Feng et al. (1997)), (b) location of the Longtan and Qingshan sections of Jiangsu Province, South China.

  • The Lower Triassic sequence in the Lower Yangtze region is well-developed in different sedimentary facies and differentiated from northeast to southwest (Zuo et al., 2006; Feng et al., 1997). The studied strata consist of the uppermost Lower Member and lowermost Upper Member of the Qinglong Formation. The Lower Qinglong Formation is composed of thin-bedded nodular limestones intercalated with calcareous mudstone and shales, and the lowermost Upper Qinglong Formation is composed of massive to thick-bedded limestones interbedded with nodular limestones. The lithological boundary between the Lower Qinglong Formation and the overlying Upper Qinglong Formation is defined by the occurrence of massive to thick-bedded limestones. The Lower Triassic geology and conodont biostratigraphy at the South Majiashan quarry were extensively studied by Liang et al. (2011), Zhao et al. (2008), and Zhao and Orchard (2007).

    Since 2009, six seasons of field investigations and excavations have been carried out in both Longtan Section and Qingshan Section. The former is located at Qinglongshan quarry 50 m south to the Longtan Village, Qixia County, and the latter is located at Qingshan quarry of Dongchang Area 20 km northeast to Jurong County, Zhenjiang City, Jiangsu Province. Many fish and invertebrate fossils along with conodont samples were collected. The fossiliferous beds at these two sections are both approximately 1 m thick (Fig. 2). Fossil fishes recorded from carbonate nodules are generally elongate-oval in shape and stratigraphically arranged in a single level (Fig. 2e), ca. 20 cm above the large carbonate nodules that lack fossil fishes (Fig. 2b). Some fossil fishes are also discovered on the lamina surface or wrapped in very thin limestone films as those reported by Tintori et al. (2014) and Tong et al. (2006). The basic sequence of those two localities are consistent although diagenesis or weathering of fish-bearing-nodules vary.

    Figure 2.  Outcrops of Early Triassic strata at the Longtan and Qingshan sections, Jiangsu Province, South China. (a), (b) Outcrop of the Longtan Section; (c) the Smithian-Spathian boundary interval at the Qingshan Section; (d) outcrop of the Qingshan Section; (e) the elongate-oval fish-bearing-nodules from the Longtan Section.

    At Longtan Section

    Red thick-bedded nodular limestone

    ————Five meters Covering————

    Bed 24 Nodular limestone. No conodonts are found.  30 cm

    Bed 25 Grey medium-bedded limestone. No conodonts are found.      25 cm

    Bed 26 Gray thin-bedded mudstone. No conodonts are found. 5 cm

    Bed 27 Grey medium-bedded limestone, yielding ramiform elements.       20 cm

    Bed 28 Greenish gray nodular limestone with serious weathering, yielding ramiform elements.      15 cm

    ————Fifty centimeters Covering————

    Bed 29 Greenish gray nodular limestone. No conodonts are found.      45 cm

    Bed 30 Grey medium-bedded limestone. No conodonts are found.      25 cm

    Bed 31 Greenish gray nodular limestone. No conodonts are found.        15 cm

    Bed 32 Grey medium-bedded limestone, yielding ramiform elements. 20 cm

    ————One hundred and Fifty centimeters Covering———

    Bed 33 Grey thick-bedded limestone. No conodonts are found. 80 cm

    Bed 34 Greenish yellow argillaceous limestone. No conodonts are found.       7 cm

    Bed 35 Greenish yellow thin-bedded argillaceous limestone with small nodules. No conodonts are found.        20 cm

    Bed 36 Yellow medium to thin-bedded argillaceous limestone with large nodules. No conodonts are found.        15 cm

    Bed 37A Greenish gray thin-bedded shale with small nodules, lamellar development, yielding Scythogondolella milleri, Scythogondolella mosheri, Scythogondolella milleri parva, and ramiform elements.        20 cm

    Bed 37B Greenish yellow thin-bedded argillaceous nodular limestone, lamellar development, yielding Scythogondolella milleri, Scythogondolella lachymiformis, Neogondolella sp., and ramiform elements.        15 cm

    Bed 38 Grey thin-bedded nodular limestone, relatively hard. No conodonts are found.        10 cm

    Bed 39 Greenish yellow thin-bedded argillaceous limestone, yielding Scythogondolella milleri, Scythogondolella

    lachymiformis, and ramiform elements.        20 cm

    Bed 40 Grey thin-bedded argillaceous nodular limestone with nodules, relatively hard, yielding Scythogondolella milleri, and ramiform elements.        8 cm

    Bed 41 Greenish gray thin-bedded mudstone, lamellar development and weathered yellow. No conodonts are found.    5 cm

    Bed 42 Greenish yellow argillaceous nodular limestone. No conodonts are found.        15 cm

    Bed 43 Greenish yellow nodular limestone with large nodules, yielding ramiform elements.        7 cm

    Bed 44 Greenish gray thin-bedded argillaceous limestone. No conodonts are found.        12 cm

    Bed 45 Greenish yellow argillaceous limestone with small nodules. No conodonts are found.        10 cm

    Bed 46 Greenish yellow thin-bedded argillaceous limestone. No conodonts are found.        10 cm

    Bed 47 The greenish yellow thin-bedded nodular limestone sandwiched the two layers of mudstone. No conodonts are found.       15 cm

    Bed 48 Gray thin-bedded argillaceous limestone. No conodonts are found.        5 cm

    Bed 49 Greenish yellow thin-bedded nodular limestone. No conodonts are found.        8 cm

    Bed 50 Gray thin-bedded argillaceous limestone. No conodonts are found.        5 cm

    Bed 51 Greenish yellow nodular limestone. No conodonts are found.        2 cm

    Bed 52 Greenish yellow thin-bedded calcareous mudstone. No conodonts are found.        11 cm

    Bed 53 Gray thin-bedded nodular limestone. No conodonts are found.        9 cm

    Bed 54 Greenish yellow thin-bedded nodular limestone. No conodonts are found.        7 cm

    Bed 55 Grey medium-bedded limestone. No conodonts are found.        37 cm

    Bed 56 Grey medium-bedded limestone. No conodonts are found.        30 cm

    ———Two hundred and Fifty centimeters Covering————

    Bed 57 Grey thick-bedded limestone, yielding Novispathodus pingdingshanensis, Borinella aff. buurensis, Novispathodus aff. abruptus, and ramiform elements.        45 cm

    Bed 58 Grey medium-bedded limestone, yielding ramiform elements.        25 cm

    Bed 59 Grey thick-bedded limestone, yielding Novispathodus pingdingshanensis, Borinella aff. buurensis, and ramiform elements.        45-50 cm

    Bed 60 Grey thick-bedded limestone, yielding Novispathodus pingdingshanensis, Borinella aff. buurensis, and ramiform elements.        120 cm

    ————Fifty centimeters Covering————

    Bed 61 Greenish yellow thin-bedded nodular limestone yielding ramiform elements.        10 cm

    Bed 62 Gray thin-bedded argillaceous limestone, yielding Novispathodus pingdingshanensis, and ramiform elements.    12 cm

    Bed 63 Greenish yellow thin-bedded nodular limestone, yielding Novispathodus pingdingshanensis, and ramiform elements.   14 cm

    Bed 64 Greenish yellow thin-bedded nodular limestone, yielding Novispathodus pingdingshanensis, and ramiform elements.    10 cm

    Bed 65 Greenish yellow thin-bedded nodular limestone, yielding Novispathodus pingdingshanensis, and ramiform elements.   8 cm

    Bed 66 Grey thick-bedded limestone, yielding Novispathodus pingdingshanensis, Cornudina sp., and ramiform elements.       180 cm

    Bed 67 Grey thick-bedded limestone, yielding ramiform elements.          220 cm

    ————Fifty centimeters Covering————

    Bed 68 Grey thick-bedded limestone, yielding Novispathodus

    pingdingshanensis, and ramiform elements.       250 cm

    ————Fifty centimeters Covering————

    Bed 69 Grey thick-bedded limestone, yielding Novispathodus pingdingshanensis, and ramiform elements.       180 cm

    Bed 70 Greenish grey thin-bedded nodular limestone, yielding Triassospathodus homeri, Novispathodus abruptus, Triassospathodus symmetricus, Novispathodus pingdingshanensis, and ramiform elements.          300 cm

    Bed 71 Grey thick-bedded limestone, yielding ramiform elements.          80 cm

    Bed 72 Greenish grey nodular limestone. No conodonts are found.          120 cm

    Bed 73 Grey medium-bedded limestone, yielding Novispathodus abruptus, Triassospathodus triangularis, Novispathodus brevissmus, Cornudina sp.. Cratognathosus kochi, and ramiform elements.          25 cm

    Bed 74 Greenish grey nodular limestone. No conodonts are found.          180 cm

    Bed 75 Grey thick-bedded limestone, yielding Novispathodus brevissmus, Cornudina sp., Icriospathodus collinsoni, Cratognathosus kochi, and ramiform elements.          450 cm

    Bed 76 Greenish grey thin-bedded nodular limestone. No conodonts are found.          30 cm

    Bed 77 Grey thick-bedded limestone, yielding Novispathodus abruptus, Triassospathodus triangularis, Novispathodus brevissmus, Cornudina sp., Icriospathodus collinsoni, Icriospathodus crassatus, Cratognathosus kochi, and ramiform elements.      140 cm

    At Jurong Section

    Bed 35 Thick-bedded limestone. No conodonts are found. 120 cm

    Bed 36 The red thin-bedded nodular limestone sandwiched the two layers of mudstone. No conodonts are found.       40 cm

    Bed 37 Red thin-bedded argillaceous limestone. No conodonts are found.          10 cm

    Bed 38 Greenish gray thin-bedded argillaceous limestone, yielding Scythogondolella milleri, Scythogondolella aff. mosheri, Scythogondolella milleri parva, Scythogondolella lachymiformis, and ramiform elements.          35 cm

    Bed 39 Greenish gray thin-bedded argillaceous limestone with large nodules, yielding Scythogondolella lachymiformis, and ramiform elements.          15 cm

    Bed 40 Greenish gray thin-bedded mudstone, yielding Novispathodus waageni and ramiform elements.          30 cm

    Bed 41 Greenish gray thin-bedded argillaceous limestone, with small nodule, yielding ramiform elements.          12 cm

    Bed 42 Greenish gray thin-bedded limestone, yielding Scythogondolella milleri, Scythogondolella lachymiformis, Neogondolella sp, and ramiform elements.          8 cm

    Bed 43 Grayish-black thin-bedded mudstone. No conodonts are found.          30 cm

    Bed 44 Greenish gray thin-bedded limestone, yielding

    Pachycladina sp. and ramiform elements.          5 cm

    Bed 45 Greenish gray thin-bedded argillaceous limestone. No conodonts are found.          5 cm

    Bed 46 Greenish gray thin-bedded limestone. No conodonts are found.          5 cm

    Bed 47 Grayish-black thin-bedded mudstone, yielding ramiform elements.          15 cm

    Bed 48 Greenish gray thin-bedded nodular limestone, yielding Pachycladina sp. and ramiform elements.          10 cm

    Bed 49 Grayish-black thin-bedded mudstone. No conodonts are found.          3 cm

    Bed 50 Greenish gray thin-bedded nodular limestone. No conodonts are found.          12 cm

    Bed 51 Grayish-black thin-bedded mudstone. No conodonts are found.          4 cm

    Bed 52 Greenish yellow nodular limestone, yielding ramiform elements.          4 cm

    Bed 53 Grayish-black thin-bedded mudstone. No conodonts are found.          2 cm

    Bed 54 Greenish yellow nodular limestone. No conodonts are found.          4 cm

    Bed 55 Grayish-black thin-bedded mudstone. No conodonts are found.          15 cm

    Bed 56 Greenish gray thin-bedded limestone, yielding Novispathodus waageni and ramiform elements.          5 cm

    Bed 57 Grayish-black thin-bedded mudstone. No conodonts are found.          1.5 cm

    Bed 58 Greenish gray thin-bedded limestone. No conodonts are found.          3 cm

    Bed 59 Gray thin-bedded limestone, yielding Pachycladina sp., Novispathodus waageni, Icriospathodus collinsoni, Novispathodus pingdingshanensis, and ramiform elements.          15 cm

    Bed 60 Greenish gray mudstone. No conodonts are found.   5 cm

    Bed 61 Grayish-black thin-bedded mudstone. No conodonts are found.          2 cm

    Bed 62 Greenish gray mudstone. No conodonts are found.   5 cm

    Bed 63 Grayish-black thin-bedded mudstone. No conodonts are found.          2 cm

    Bed 64 Greenish yellow thin-bedded limestone, Novispathodus pingdingshanensis, and ramiform elements.          10 cm

    Bed 65 Grayish-black thin-bedded mudstone. No conodonts are found.          30 cm

    Bed 66 Greenish yellow thin-bedded limestone. No conodonts are found.          5 cm

    Bed 67 Grayish-black thin-bedded mudstone. No conodonts are found.          10 cm

    Bed 68 Greenish yellow thin-bedded limestone. No conodonts are found.          5 cm

    Bed 69 Grayish-black thin-bedded mudstone. No conodonts are found.          30 cm

    Bed 70 Greenish yellow thin-bedded limestone, yielding Novispathodus waageni, Icriospathodus collinsoni, Novispathodus brevissmus, Novispathodus eotriangularis, Novispathodus pingdingshanensis, Triassospathodus symmetricus, and ramiform elements.          10 cm

    Bed 71 Grayish-black thin-bedded mudstone. No conodonts are

    found.          3 cm

    Bed 72 Gray thin-bedded limestone. No conodonts are found.15 cm

    Bed 73 Greenish gray thin-bedded mudstone. No conodonts are found.          8 cm

    Bed 74 Grey medium-bedded limestone, yielding ramiform elements.          30 cm

    Bed 75 Greenish yellow thin-bedded argillaceous limestone, yielding ramiform elements.          12 cm

    Bed 76 Grey medium-bedded limestone, yielding ramiform elements.          40 cm

    Bed 77 Greenish gray thin-bedded mudstone, yielding Novispathodus eotriangularis, Novispathodus pingdingshanensis, Triassospathodus symmetricus, and ramiform elements.          12 cm

    Bed 78 Grey medium-bedded limestone. yielding Novispathodus pingdingshanensis, and ramiform elements.          400 cm

    Bed 79 Greenish grey nodular limestone. yielding ramiform elements.          20 cm

    Bed 80 Mudstone interbedded with limestone. No conodonts are found.          15 cm

    Bed 81 Greenish gray thin-bedded limestone. No conodonts are found.          25 cm

    Bed 82 Grayish-black nodular argillaceous limestone. No conodonts are found.          30 cm

    Bed 83 Greenish grey thin-bedded nodular argillaceous limestone. No conodonts are found.          70 cm

    Bed 84 Grayish-black nodular argillaceous limestone. No conodonts are found.          15 cm

    Bed 85 Greenish grey thin-bedded nodular argillaceous limestone, weathered red, yielding Triassospathodus homeri, Triassospathodus triangularis, and ramiform elements.          250 cm

    Bed 86 Gray thin-bedded limestone, yielding Triassospathodus triangularis, Cratognathosus kochi, Cornudina sp., Neogondolella n. sp. B, and ramiform elements.          20 cm

    Bed 87 Greenish grey thin-bedded nodular argillaceous limestone, weathered red, yielding ramiform elements.          100 cm

    Bed 88 Greenish gray thin-bedded mudstone. No conodonts are found.          12 cm

    Bed 86 Gray thin-bedded limestone, yielding Triassospathodus symmetricus, and ramiform elements.          32 cm

  • A total of 101 samples were collected from the uppermost lower and lowermost Upper Qinglong Formation at these two localities for conodont study, each weighing about 4 kg. Of them, 52 samples were collected from Longtan (LT) Section and 49 samples were collected from Qingshan (QS) Section. All conodont samples, after coarsely crushed into ~2×2 cm pieces, were dissolved by diluted acetic acid (ca. 10%) and then filtered through 20-mesh and 120-mesh sieves in the conodont laboratory of the Peking University. Conodonts were carefully hand-picked from sieved (mesh size 0.125 mm) insoluble residues under a stereo-microscope. Photographs were taken using a Scanning Electronic Microscope (Quanta FEG 650) at the Key Laboratory of Orogenic Belt and Crustal Evolution, Ministry of Education, Peking University. All illustrated specimens are deposited in the collection of the Geological Museum of Peking University, Beijing, China (GMPKU).

  • Based on the vertical range of conodonts at the two sections in Jiangsu Province, i.e., Longtan and Qingshan sections, three conodont zones from the Latest Smithian to the Spathian were recognized, in ascending order: 1. Scythogondolella milleri Zone, 2. Novispathodus pingdingshanensis Zone, and 3. Triassospathodus aff. homeri Zone. The distribution of the main conodont taxa and the conodont zones of those two sections are shown in Fig. 3 and the related conodont zones are described as follows.

    Figure 3.  Stratigraphic distribution of Early Traissic conodonts at the Longtan Section and Qingshan Section, and the correlation among the Longtan, Qingshan, South Majiashan sections. The conodont data of the South Majiashan Section, Chaohu County, Anhui Province are from Liang et al. (2011) and Zhao et al. (2005). Abbreviations: Sc. Scythogondolella; Nv. Novispathodus; Ns. Neospathodus; Tr. Triassospathodus; Ic. Icriospathodus.

  • The Sc. milleri Zone is based on the occurrence of Sc. milleri (Plates 1, 2) below the first occurrence of Nv. pingdingshanensis (Plate 3). The associated conodonts at the Longtan Section are Sc. aff. mosheri, Sc. milleri parva, Sc. ellesmerensis, Sc. lachymiformis, Sc. aff. lachymiformis, Pachycladina sp. At the Qingshan Section co-occurring conodonts include Sc. aff. mosheri, Sc. milleri parva, Sc. lachymiformis, Neogondolella sp., Pachycladina sp., Nv. waageni. At Longtan Section, the zone corresponds to a 5.11 m thick interval from Bed 37 to Bed 57, while it is 2.27 m thick from Bed 38 to Bed 59 at the Qingshan Section. This zone might range from lower strata, however, with our limited data, the base could not be defined because it was not exposed (Fig. 3).

    Figure Plate1.  SEM photos of conodonts from the Lower Triassic of Longtan Section (a. lateral view, b. aboral view, c. oral view). 1-2. Scythogondolella milleri (Müller, 1956), LT-37; 3, 6, 8. Scythogondolella lachrymiformis (Orchard, 2008), LT-39; 4. Scythogondolella milleriparva (Kozur and Mostler, 1976), LT37; 5. Scythogondolella ellesmerensis (Orchard, 2008), LT-37; 7. Scythogondolella aff. lachrymiformis (Orchard, 2008), LT-40; 9. Ozarkodina tortilis (Tatge, 1956), LT-59.

    Figure Plate2.  SEM photos of conodonts from the Lower Triassic strata of Qingshan Section. 1, 2, 9. Scythogondolella milleri (Müller, 1956), a. lateral view, b. oral view, c. aboral view, 1, 2, QS-38. 9, QS-42; 3, 6, 10. Novispathodus pingdingshanensis (Zhao and Orchard, 2007), a. lateral view, b. oral view, c. aboral view, 3, 10. QS-64. 6. QS-70; 4. Scythogondolella milleri parva (Kozur and Mostler, 1976), a. lateral view, b. oral view, c. aboral view, QS-38; 5. Scythogondolella aff. mosheri (Kozur and Mostler, 1976), a. lateral view, b. oral view, c. aboral view, QS-38; 7. Novispathodus waageni (Zhao et al., 2008), a. lateral view, b. aboral view, QS-70; 8, 11. Triassospathodus symmetrucis (Orchard, 1995), a. lateral view, b. oral view, c. aboral view, 8. QS-89, 11. QS-85; 12. Icriospathodus crassatus (Orchard, 1995), a. lateral view, b. oral view, QS-70; 13. Cratognathodus kochi (Huckriede, 1958), lateral view, QS-86.

    Figure Plate3.  SEM photos of conodonts from the Lower Triassic strata of Longtan Section. 1, 2, 4, 5, 7. Novispathodus pingdingshanensis (sensu Zhao and Orchard, 2007) a. lateral view, b. oral view, c. aboral view, 1, LT-57, 2, 4, LT-59, 5, LT-69, 7, LT-63; 3, 6. Neospathodus aff. clinatus (sensu Chen et al., 2015) 3a, 6a. lateral view, 3, LT-57, 6, LT-70; 8. Novispathodus waageni (Zhao et al., 2008) 8a. lateral view, b. oral view LT-60; 9, 10. Borinella aff. buurensis (Chen et al., 2015) a. lateral view, b. oral view, c. aboral view, 9, 10, LT-60; 11. Novispathodus aff. abruptus (Orchard, 1995) 11a. lateral view, 11b. oral view, 11c. aboral view, LT-57.

  • The base of the Nv. pingdingshanensis Zone is defined by the first occurrence of the Nv. pingdingshanensis (Plates 2, 3), and the top by the appearance of Triassospathodus aff. homeri (Plate 4). At the Longtan Section, the zone corresponds to a 12.84 m thick interval from Bed 57 to Bed 70, while it is 10.23 m thick from Bed 59 to Bed 85 at the Qingshan Section. The index conodont related to Ns. aff. clinatus, Borinella aff. buurensis, Nv. waageni, Nv. aff. abruptus, Cornudina sp., Pachycladina sp. at the Longtan Section. At the Qingshan Section, Nv. pingdingshanensis co-occurs with Pachycladina sp., Nv. waageni, Nv. eotriangularis, Ns. brevissimus, Tr. symmetricus, Icriospathodus crassatus.

    Figure Plate4.  SEM photos of conodonts from the Lower Triassic strata of Longtan Section. 1, 2. Triassospathodus aff. homeri (Bender, 1970), 1a. 1b. 2a. 2b. oral and aboral view, LT-70 (broken during the lateral SEM photography); 3. Triassospathodus triangularis (Bender, 1968), 3a. 3b. oral and aboral view, LT-70 (broken during the lateral SEM photography); 4, 5. Cratognathodus kochi (Huckriede, 1958), 4a. lateral view, LT-73, 5a. lateral view, LT-73; 6-8. Icriospathodus collinsoni (Solien, 1979), 6a, 6b, 8a, 8b. oral and aboral view, 7a, 7b. lateral and oral view, LT-77; 9. Neogondolella? n. sp. B (Chen et al., 2015), lateral view, LT-75; 10, 14. Icriospathodus crassatus (Orchard, 1995), 10a. oral view, 10b. aboral view, LT-77, 14a, 14b lateral and oral view, LT-77; 11. Novispathodus abruptus (Orchard, 1995), 11a. lateral view, 11b. aboral view, LT-73; 12, 13, 19. Neogondolella? n. sp. A (Chen et al., 2015), 12a, 12b. lateral and oral view, LT-77, 19a. lateral view, LT-77; 15, 18. Neospathodus brevissimus (Orchard, 1995), 15a, 15b. lateral and aboral view, LT-73, 18. lateral view, LT-73; 16. Triassospathodus symmetricus (Orchard, 1995), 16a. lateral view, LT-77; 17. Cornudina sp. (Orchard et al. 2007a), 17a. lateral view, LT-77.

  • This zone starts with the first occurrence of Tr. aff. homeri (Plates 2, 4). At the Longtan Section it begins from Bed 70 and at the Qingshan Section from Bed 85, while its upper boundary is not defined at our samping sections in this work. At the Longtan Section, Tr. aff. homeri appears concurrently with Tr. triangularis, Cratognathosus kochi, Ng.? n. sp. B, Icriospathodus collinsoni, Ic. crassatus, Nv. abruptus, Ng.? n. sp. A, Tr. symmetricus, Ns. brevissimus, and Cornudina sp.. The associated conodonts at the Qingshan Section include Tr. triangularis, Tr. symmetricus, Cratognathodus kochi, Spathicuspus spathi, Ng.? n. sp. B.

  • As described above, three conodont zones, i.e., Scythogondolella milleri Zone, Novispathodus pingdingshanensis Zone and Triassospathodus aff. homeri Zone, are recognized from the uppermost Lower and lowermost Upper Qinglong Formation in both Longtan and Qingshan sections. An intensive correlation with the coeval conodont zones globally suggests that the strata of the uppermost Lower and Lowermost Upper Qinglong Formation span from the Latest Smithian to the Spathian (Olenekian, Early Triassic) (Table 1).

    Table 1.  Correlation of the conodont zones of Longtan and Qingshan sections with sections over the world. Abbreviations: Bo., Borinella; Ch., Chiosella; Co., Conservatela; Ic., Icriospathodus; Ds., Discretella; Ng., Neogondolela; Ns., Neospathodus; Nw, Novispathodus; Par., Parachirognathus; Pu, Paullella; Sc., Scythogondolella; Tr, Triassospathodus

  • The index species of the Sc. milleri Zone is associated at its type locality with the Latest Smithian ammonoids of Anawasatchites tardus Zone (Müller, 1956), as was later confirmed in the other North American localities (Idaho, Utah, Nevada; Sweet et al., 1971; Clark, 1959), in the Wapiti region of British Columbia and the Canadian Arctic, Canada (Orchard and Zonneveld, 2009; Orchard, 2008; Mosher, 1973) and in Svalbard (Nakrem et al., 2008). This cosmopolitan age-diagnostic conodont species is also recorded in other palaeogeographic provinces such as Afghanistan (Sweet, 1970), Nepal (Fuchs and Mostler, 1969), Japan, Timor (Nogami, 1968), Spiti of India (Krystyn et al., 2007; Krystyn, 2005), Nyalam of Tibet (Tian, 1982) and Maduo of Qinghai, China (Fang et al., 2015). Accordingly, the Sc. milleri Zone is always considered as the uppermost conodont zone in the Smithian substage of the Olenekian Stage, Early Triassic (Orchard and Zonneveld, 2009; Kozur, 2003; Sweet et al., 1971), above the Nv. waageni Zone (Krystyn et al., 2007; Krystyn, 2005; Tian, 1982) or laterally correlated with the uppermost part of the Nv. waageni Zone (Orchard, 2008; Orchard and Tozer, 1997; Solien, 1979). Additionally, the composition of the Sc. milleri Zone in the present paper, including different Sc. spp. (e.g., Sc. milleri, Sc. milleri parva, Sc. lachrymiformis, Sc. mosheri), Nv. waageni and Ng. sp., closely resembles that of the conodont faunas reported from the ammonoid Anawasatchites tardus Zone of the Canadian Arctic (Orchard, 2008), Wapiti Lake area (Orchard and Zonneveld, 2009) and Svalbard (Nakrem et al., 2008), although the conodont Sc. Lachrymiformis does not overlap with Sc. milleri in either Wapiti or the Canadian Arctic, and was not recorded at all in Svalbard.

  • The index species of Nv. pingdingshanensis Zone was originally suggested to correspond to the ammonoid Columbites-Tirolites Zone in the Nanlinghu Formation, Chaohu, Anhui Province (Zhao and Orchard, 2007). The according Nv. pingdingshanensis Zone was proposed overlying the Nv. waageni Zone by Zhao et al. (2007) in view of its phylogenetic relationship with Nv. waageni. Although the stratigraphic range is short, Nv. pingdingshanensis Zone is distinctive with high abundance of nominal species and a constant distribution in three sections of Chaohu (i.e., West Pingdingshan, North Pingdingshan and South Majiashan; Zhao et al., 2008; Zhao and Orchard, 2007), Anhui Province; in Jiarong Section of Huishui, Guizhou Province (Chen et al., 2015); in Daxiakou Section of the Three Gorges area, Hubei Province (Zhao et al., 2013) and in Longtan and Qingshan sections discussed above. The zonal species also occured in the Lower Triassic of the Qingyan area of Guizhou (Ji et al., 2011) and in Guangxi, South China, although the relevant conodont zone was not recognized in those localities. Age of the Nv. pingdingshanensis Zone was originally suggested the Early Spathian calibrated with the associated ammonoids of the Columbites-Tirolites Zone at South Majiashan (Zhao and Orchard, 2007; Tong et al., 2004). Later, the first occurrence of Nv. pingdingshanensis was proposed as an ideal marker for the Smithian-Spathian boundary because its first appearance correlates well with the largest positive carbon isotopic excursion of the Early Triassic in Chaohu (Liang et al., 2011). With the help of the above assumption, the Nv. pingdingshanensis Zone is laterally well-correlated in South China (Chen et al., 2016, 2015; Zhao et al., 2013, 2008; Liang et al., 2011; Zhao and Orchard, 2007 and the present paper). Outside South China, Nv. pingdingshanensis Zone was broadly correlated with the Tr. hungaricus Zone in Central Europe (Kozur, 2003), the Ic. crassatus Zone in Oman, Italy and California (Orchard, 1995), and the lower part of the Ic. collinsoni Zone in Spiti, India (Krystyn et al., 2007; Krystyn, 2005). However, Nv. pingdingshanensis could appear slightly early in the uppermost Smithian strata from the Sulphur Mountain Formation in the Wapiti Lake area, Canada (Orchard and Zonneveld, 2009), from the Bac Thuy Formation in the Lang Son Province, Vietnam (Komatsu et al., 2016), and from Guryul Ravine and Salt Range (Leu et al., 2018). Thus, the base of the Spathian was placed immediately after the peak of δ13C curve (Zhang et al., 2019; Leu et al., 2018; Komatsu et al., 2016; Orchard and Zonneveld, 2009), and accordingly we herein place Smithian-Spathian boundary immediately after the first occurrence of Nv. pingdingshanensis at the studied sections.

  • Tr. homeri is widely distributed in various palaeogeographic provinces (Orchard, 2008; Zhao and Orchard, 2007; Bender, 1970). In South China the Tr. homeri Zone was firstly reported from the Jialingjiang Formation of Hubei (Wang and Cao, 1981). Later on, it was also recorded from the Luolou Formation in Guangxi and Guizhou (Liang et al., 2016; Yan et al., 2013; Ji et al., 2011; Wang et al., 2005; Wang and Zhong, 1994), Yongningzhen Formation and Ziyun Formation in Guizhou (Chen et al., 2015; Yang and Chu, 1992), Jialingjiang Formation in Sichuan (Jiang et al., 2000), Garencuo Formation in Tibet (Wu et al., 2007), Nanlinghu Formation in Anhui (Zhao et al., 2008; Zhao and Orchard, 2007), and Upper Qinglong Formation in Jiangsu (Chen, 1996, and the present paper). Outside of South China, this species is also found from the uppermost part of the Narmia Member of Mianwali Formation in Pakistan (Sweet, 1970); Nodular limestone of the Khunamuh Formation in Kashmir, Pakistan (Chhabra and Sahni, 1981), Kalapani limestone in Kumaun of Tethys Himalaya, India (Chhabra and Kumar, 1992); Thaynes Formation near Salt Lake City, Utah (Solien, 1979); the Grayling Formation in western Canada (Henderson, 1997), and the upper part of the Vega Member of the Sulphur Mountain Formation, British Columbia (Orchard and Zonneveld, 2009). Because Tr. triangularis, Tr. symmetricus and Ic. collinsoni are usually associated with Tr. homeri in this Zone, the Tr. homeri Zone can be broadly correlated with the Ic. collinsoni Zone (Chen et al., 2015; Krystyn, 2005; Kozur, 2003; Orchard and Tozer, 1997; Solien, 1979; Sweet et al., 1971), the Tr. symmetricus-Tr. homeri Zone (Wang et al., 2005), and also Tr. homeri-Tr. triangularis Zone (Liang et al., 2016).

    The holotype of Tr. homeri comes from strata at Chios slightly above the Prohungarites/Subcolumbites beds (Gaetani et al., 1992), with a Late Spathian (Olenekian) age. In America, Tr. homeri, as revised by Orchard (1995), coexists with ammonoid Subcolumbites and Procolumbites in Idaho (Hammond Creek) and Nevada (Tobin and Humboldt ranges) (Orchard, 2008), suggesting a possible Middle Spathian age. In Anhui of South China, exhaustive conodont and ammonoid data confirm that Tr. homeri lies within Columbites-Tirolites Zone (Zhao et al., 2008; Zhao and Orchard, 2007; Tong et al., 2004), with a Middle Spathian age. However, the co-occurrence with hiosella timorensis and Gladigondolella tethydis in China (Orchard et al., 2007a) and Romania (Orchard et al., 2007b) indicated that Tr. homeri possibly enters the Anisian.

  • The fish-bearing-nodule level lies in the upper part of the Lower Qinglong Formation (1.97 m below the base of the Upper Qinglong Formation at the Longtan Section and 1.54 m below the base of the Upper Qinglong Formation at the Qingshan Section, within the Sc. milleri Zone (Fig. 3). There is no doubt that the Early Triassic fish-bearing-nodule levels at Jiangsu are attributed to the Latest Smithian, since Sc. milleri is an undisputed age-diagnostic species of Latest Smithian (Orchard and Zonneveld, 2009; Krystyn et al., 2007; Krystyn, 2005; Kozur, 2003; Sweet et al., 1971). In Chaohu, Anhui Province, the fish-bearing-nodule level belongs to the upper part of the Helongshan Formation, ca. 3.2 m below the base of the overlying Nanlinghu Formation (Liang et al., 2011; Tong et al., 2006). Accordingly, it lies in the upper part of Nv. waageni Zone, only 1.5 m below the first occurrence of Nv. pingdingshanensis (Liang et al., 2011; Zhao et al., 2008; Zhao and Orchard, 2007), with a Latest Smithian age. Therefore, it is still highly debated that whether the first occurrence of Nv. pingdingshanensis can be used as a marker of the Smithian-Spathian boundary or not (Zhang et al., 2019; Leu et al., 2018; Komatsu et al., 2016; Zhao et al., 2013; Liang et al., 2011; Orchard and Zonneveld, 2009). Based on the above-mentioned conodont correlations. We herein suggest that the fish-bearing-nodule levels of Chaohu, Longtan and Qingshan are coeval, with an end-Smithian in age.

  • A systematic and successional study of the conodont is presented at the Longtan and Qingshan sections, Jiangsu Province, that have yielded the Early Triassic fish-bearing-nodule levels. Three conodont zones, i.e., Sc. milleri Zone, Nv. pingdingshanensis Zone and Tr. aff. homeri Zone, are recognized in ascending order and suggest that the uppermost Lower Qinglong Formation and the lowermost Upper Qinglong Formation ranges from the Latest Smithian to Middle Spathian of Olenekian, Early Triassic. This sequence is correlated well with other conodont successions in South China and all over the world, allowing a more precise comparison among different sections than before. The Early Triassic fish-bearing-nodule levels of Longtan and Qingshan sections occur in the Sc. milleri Zone which is laterally correlated well with the upper part of the Nv. waageni Zone of Chaohu in which the fish-bearing-nodule level is yielded. Therefore, the Early Triassic fish-bearing-nodule levels in the Lower Yangtze region are approximately coeval based on conodont biostratigraphy, with an end-Smithian in age.

  • The authors are grateful to Ryosuke Motani (University of California, Davis) and Andera Tintori (Università degli Studi di Milano) for their constructive suggestions and language corrections on an early version of the manuscript. Special thanks go to Michael Orchard (Geological Survey of Canada) for his helpful comments on conodont taxonomy. Hao Lu, Wenbin Lin, Xin Yu and Peigang Ni (students of Peking University) participated the field work. Martyn Golding (Geological Survey of Canada) and an anonymous reviewer provided many constructive comments, greatly improving the quality of the paper. Research was funded by the Stratefic Priority Research Program of the Chinese Academy of Science (No. XDA14010404), the National Science Foundation of China (Nos. 41572008, U1663201, 41372016, 40920124002, 1402014), the Ministry of Science and Technology (No. 2016YFC0503301), the State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, CAS) (Nos. 123107, 143108, 173123), and the China Geological Survey (No. 121201102000150012-09). The final publication is available at Springer via https://doi.org/10.1007/s12583-019-1232-y.

Reference (63)

Catalog

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return