Articles | Volume 45, issue 1
https://doi.org/10.5194/jm-45-377-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/jm-45-377-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Latest Guadalupian to Lopingian conodonts from western Hubei–eastern Chongqing, South China
Bingyang Zhou
Hubei Key Laboratory of Resource and Eco-Environment Geology, Hubei Institute of Geosciences, Hubei Geological Bureau, Wuhan, 430034, China
Kui Wu
CORRESPONDING AUTHOR
Hubei Key Laboratory of Resource and Eco-Environment Geology, Hubei Institute of Geosciences, Hubei Geological Bureau, Wuhan, 430034, China
Teng Song
Oil and Gas Survey, China Geological Survey, Beijing 100083, China
Lulu Xu
Hubei Geological Survey, Wuhan 430034, China
Ke Duan
Hubei Geological Survey, Wuhan 430034, China
Jinling Yuan
Hubei Key Laboratory of Resource and Eco-Environment Geology, Hubei Institute of Geosciences, Hubei Geological Bureau, Wuhan, 430034, China
Liangzhe Yang
Hubei Key Laboratory of Resource and Eco-Environment Geology, Hubei Institute of Geosciences, Hubei Geological Bureau, Wuhan, 430034, China
Bi Zhao
Hubei Key Laboratory of Resource and Eco-Environment Geology, Hubei Institute of Geosciences, Hubei Geological Bureau, Wuhan, 430034, China
Jiangli Li
Hubei Key Laboratory of Resource and Eco-Environment Geology, Hubei Institute of Geosciences, Hubei Geological Bureau, Wuhan, 430034, China
Di Wang
Hubei Key Laboratory of Resource and Eco-Environment Geology, Hubei Institute of Geosciences, Hubei Geological Bureau, Wuhan, 430034, China
Boyong Yang
CORRESPONDING AUTHOR
Hubei Key Laboratory of Resource and Eco-Environment Geology, Hubei Institute of Geosciences, Hubei Geological Bureau, Wuhan, 430034, China
Cited articles
Bagherpour, B., Bucher, H., Yuan, D. X., Leu, M., Zhang, C., and Shen, S. Z.: Early Wuchiapingian (Lopingian, late Permian) drowning event in the South China block suggests a late eruptive phase of Emeishan large Igneous Province, Global Planet. Change, 19, 119–132, https://doi.org/10.1016/j.gloplacha.2018.07.013, 2018a.
Bagherpour, B., Bucher, H., Schneebeli-Hermann, E., Vennemann, T., Chiaradia, M., and Shen, S. Z.: Early Late Permian coupled carbon and strontium isotope chemostratigraphy from South China: Extended Emeishan volcanism?, Gondwana Res., 58, 58–70, https://doi.org/10.1016/j.gr.2018.01.011, 2018b.
Bagherpour, B., Lena, L., Ovtcharova, M., Yuan, D. X., Shen, S. Z., Bucher, H., and Schaltegger, U.: Correlating early Wuchiapingian (early Lopingian/late Permian) biotic and environmental changes with eruptive activity of the Emeishan LIP, Lithios, 494–495, 107937, https://doi.org/10.1016/j.lithos.2024.107937, 2025.
Chen, B., Joachimski, M. M., Shen, S. Z., Lambert, L. L., Lai, X. L., Wang, X. D., Chen, J., and Yuan, D. X.: Permian ice volume and palaeoclimate history: Oxygen isotope proxies revisited, Gondwana Res., 24, 77–89, https://doi.org/10.1016/j.gr.2012.07.007, 2013.
Cheng, C., Zhang, H., Wang, D., Li, S. Y., and Shen, S. Z.: Pulsed volcanism in the Emeishan Large Igneous Province drove deglaciation during the Guadalupian-Lopingian transition, Palaeogeogr. Palaeocl., 679, 113302, https://doi.org/10.1016/j.palaeo.2025.113302, 2025.
Du, M. Y., Wu, K., Huang, Y. F., Yang, B. Y., Yang, L. Z., Wang, Y. D., Zhao, J. J., Li, M. F., and Huang, Z. H.: Conodont biostratigraphy around the Permian-Triassie boundary from the Jianzishan section, Lichuan, Hubei Province, and its implicationsfor the age of microbialites, Acta Geol. Sin., 99, 2204–2216, 2025 (in Chinese with English abstract).
Fan, J. X., Shen, S. Z., Erwin, D. H., Sadler, P. M., Macleod, N., Cheng, Q. M., Hou, X. D., Yang, J., Wang, X. D., Wang, Y., Zhang, H., Chen, X., Li, C., and Zhao, Y. Y.: A high-resolution summary of Cambrian to Early Triassic marine invertebrate biodiversity, Paleontology, 367, 272–277, 2020.
Fielding, C. R., Frank, T. D., Birgenheier, L. P., Rygel, M., Jones, A. T., and Roberts, J.: Stratigraphic imprint of the Late Paleozoic Ice Age in eastern Australia: A record of alternating glacial and nonglacial climate regime, J. Geol. Soc., 165, 129–140, https://doi.org/10.1144/0016-76492007-036, 2008.
Gong, Z., Crowley, J. L., Kamo, S. L., Denyszn, S. W., Zhang, M. C., Li, J., Liu, Y. M., and Huang, C. M.: Protracted post–eruptive basaltic weathering of the Emeishan large igneous province constrained by U–Pb CA–ID–TIMS geochronology, Palaeogeogr. Palaeocl., 659, 112666, https://doi.org/10.1016/j.palaeo.2024.112666, 2025.
Gullo, M. and Kozur, H. W.: Conodonts from the pelagic deep-water Permian of central western Sicily (Italy), Neues Jahrb. Geol. P., 184, 203–234, 1992.
Guo, X. S., Wang, R. Y., Shen, B. J., Wang, G. P., Wan, C. X., and Wang, Q. R.: Geological characteristics, resource potential, and development direction of shale gas in China, Petrol. Explor. Dev., 52, 17–32, https://doi.org/10.1016/S1876-3804(25)60002-4, 2025.
Henderson, C. M.: Permian conodont biostratigraphy, Geol. Soc. Lond. Spec. Publ., 450, 119–142, https://doi.org/10.1144/SP450.9, 2018.
Hou, Z. S., Fan, J. X., Henderson, C. M., Yuan, D. X., Shen, B. H., Wu, J., Wang, Y., Zheng, Q. F., Zhang, Y. C., Wu, Q., and Shen, Z.: Dynamic palaeogeographic reconstructions of the Wuchiapingian Stage (Lopingian, Late Permian) for the South China Block, Palaeogeogr. Palaeocl., 546, 109667, https://doi.org/10.1016/j.palaeo.2020.109667, 2020.
Hu, D. G., Zhou, L., Bao, H. Y., Liu, H. T., Liu, C., Meng, Z. Y., Zhao, S., and Wang, J.: Breakthrough and significance of Permian shale gas exploration of Well HY1 in Hongxing area, eastern Sichuan Basin, Acta Petrol. Sin., 44, 241–252, https://doi.org/10.7623/syxb202302002, 2023 (in Chinese with English abstract).
Huang, H., Huyskens, M. H., Yin, Q. Z., Cawood, P. A., Hou, M. C., Yang, J. H., Xiong, F. H., Du, Y. S., and Yang, C. C.: Eruptive tempo of Emeishan large igneous province, southwestern China and northern Vietnam: Relations to biotic crises and paleoclimate changes around the Guadalupian-Lopingian boundary, Geology, 50, 1083–1087, https://doi.org/10.1130/G50183.1, 2022.
Jin, Y. G., Shen, S. Z., Henderson, C. M., Wang, X. D., Wang, W., Wang, Y., Cao, C. Q., and Shang, Q. H.: The Global Stratotype Section and Point (GSSP) for the boundary between the Capitanian and Wuchiapingian Stage (Permian), Episodes, 29, 253–262, 2006a.
Jin, Y. G., Wang, Y., Henderson, C., Wardlaw, B. R., Shen, S. Z., and Cao, C. Q.: The Global Boundary Stratotype Section and Point (GSSP) for the base of Changhsingian Stage (Upper Permian), Episodes, 29, 175–182, 2006b.
Kozur, H. W.: Beitrage zur conodontenfauna des Perm, Geologische Palaontologische Mitteilungen Innsbruck, 5, 1–44, 1975.
Kozur, H. W.: Pelagic uppermost Permian and the Permian–Triassic boundary conodonts of Iran. Part II: investigated sections and evaluation of the conodonts fanuas, Hallesches Jahrbuch Geowiss, Reihe B, Beiheft, 19, 49–86, 2005.
Li, M. L., Yang, B. Y., Qiu, L., Zhang, Y. J., Xu, H., Shi, X. B., Tian, W. X., Wang, Y., Gao, J., and Zheng, D. S.: Emeishan felsic volcanism lasted until the Changhsingian? New evidence from volcanic ash in the northern South China block, J. Asian Earth Sci., 238, 105390, https://doi.org/10.1016/j.jseaes.2022.105390, 2022.
Li, S. Z., Yang, X. G., Xu, Q. C., Li, F., Song, T., Li, H. H., Wei, S. Y., Wang, C., and Wang, Y. L.: Permian Dalong Formation – a new formation for shale gas exploration and development, Geol. Rev., 70, 253–254, http://https://doi.org/10.16509/j.georeview.2024.s1.137, 2024 (in Chinese with English abstract).
Li, Z. S., Zhan, L. P., Dai, J. Y., Jin, R. G., Zhu, X. F., Zhang, J. H., Huang, H. Q., Xu, D. Y., Yan, Z., and Li, H. M.: Study on the Permian–Triassic Biostratigraphy and Event Stratigraphy of Northern Sichuan and Southern Shaanxi, Geological Publishing House, Beijing, 435, 1989 (in Chinese with English abstract).
Lyu, Z. Y., Orchard, M. J., Chen, Z. Q., Wang, X. D., Zhao, L. S., and Han, C.: Uppermost Permian to Lower Triassic conodont successions from the Enshi area, western Hubei Province, South China, Palaeogeogr. Palaeocl., 519, 49–64, https://doi.org/10.1016/j.palaeo.2017.08.015, 2019.
Mei, S. L., Jin, Y. G., and Wardlaw, B. R.: Succession of Conodonts Zones From The Permian “Kuhfeng” Formation, Xuanhan, Sichuan, And Its Implication In Global Correlation, Acta Palaeontol. Sin., 33, 1–23+131–133, https://doi.org/10.19800/j.cnki.aps.1994.01.001, 1994a (in Chinese with English abstract).
Mei, S. L., Jin, Y. G., and Wardlaw, B. R.: Succession of Wuchiapingian Conodonts From Northeastern Sichuan And Its Worldwide Correlation, Acta Micropalaeontologica Sinica, 11, 121–139, 1994b.
Mei, S. L., Jin, Y. G., and Wardlaw, B. R.: Zonation Of Conodonts Form The Maokouan–Wuchiapingian Boundary Strata, South China, Palaeoworld, 4, 225–233, 1994c.
Mei, S. L., Henderson, C. M., and Cao, C. Q.: Conodont sample-population approach to defining the base of the Changhsingian Stage, Lopingian Series, Upper Permian, Geol. Soc. Lond. Spec. Publ., 230, 105–121, 2004.
Meng, Q., Xue, W.Q., Chen, F. Y., Yan, J. X., Cai, J. H., Sun, Y. D., Wignall, P. B., Liu, K., Liu, Z. C., and Chen, D.: Stratigraphy of the Guadalupian (Permian) siliceous deposits from central Guizhou of South China: Regional correlations with implications for carbonate productivity during the Middle Permian biocrisis, Earth Sci. Rev., 228, 104011, https://doi.org/10.1016/j.earscirev.2022.104011, 2022.
Metcalfe, I. and Crowley, J. L.: Upper Permian and Lower Triassic conodonts, high-precision U-Pb zircon ages and the Permian-Triassic boundary in the Malay Peninsula, J. Asian Earth Sci., 199, 104403, https://doi.org/10.1016/j.jseaes.2020.104403, 2020.
Nafi, M., Xia, W. C., and Zhang, N.: Late Permian (Changhsingian) conodont biozonation and the basal boundary, Ganxi section, western Hubei Province, south China, Can. J. Earth Sci., 43, 121–133, https://doi.org/10.1139/E05-097, 2006.
Qiu, Z., Dou, L. R., Wu, J. F., Wei, H. Y., Liu, W., Kong, W. L., Zhang, Q., Cai, G. Y., Zhang, G., Wu, W., Li, S. Z., Qu, T. Q., and Gao, W. L.: Lithofacies Palaeogeographic Evolution of the Middle Permian Sequence Stratigraphy and Its Implications for Shale Gas Exploration in the Northern Sichuan and Western Hubei Provinces, Earth Sci., 49, 712–748, https://doi.org/10.3799/dqkx.2023.216, 2024.
Ramezani, J. and Bowring, S. A.: Advances in numerical calibration of the Permian timescale based on radioisotopic geochronology, Geol. Soc. Lond. Spec. Publ., 450, 51–60, https://doi.org/10.1144/SP450.17, 2018.
Shellnutt, J. G., Pham, T. T., Denyszyn, S. W., Yeh, M. W., and Tran, T. A.: Magmatic duration of the Emeishan large igneous province: insight from northern Vietnam, Geology, 48, 457–461, https://doi.org/10.1130/g47076.1, 2020.
Shen, S. Z.: The Permian GSSPs and timescale: Progress, unsolved problems and perspectives, Permophiles, 75, 12–18, 2023.
Shen, S. Z. and Mei, S. L.: Lopingian (Late Permian) high-resolution conodont biostratigraphy in Iran with comparison to South China zonation, Geol. J., 45, 135–161, https://doi.org/10.1002/gj.1231, 2010.
Shen, S. Z., Crowley, J. L., Wang, Y., Bowring, S. A., Erwin, D. H., Sadler, P. M., Cao, C. Q., Rothman, D. H., Henderson, C. M., Ramezani, J., Zhang, H., Shen, Y., Wang, X. D., Wang, W., Mu, L., Li, W. Z., Tang, Y. G., Liu, X. L., Liu, L. J., Zeng, Y., Jiang, Y. F., and Jin, Y. G.: Calibrating the End-Permian Mass Extinction, Science, 334, 1367–1372, https://doi.org/10.1126/science.1213454, 2011.
Shen, S. Z., Zhang, H., Zhang, Y. C., Yuan, D. X., Chen, B., He, W. H., Mu, L., Lin, W., Wang, W. Q., Chen, J., Wu, Q., Cao, C. Q., Wang, Y., and Wang, X. D.: Permian integrative stratigraphy and timescale of China, Sci. China Earth Sci., 62, 154–188, https://doi.org/10.1007/s11430-017-9228-4, 2019.
Shen, S. Z., Yuan, D. X., Zhang, Y. C., Henderson, C. M., Zheng, Q. F., Zhang, H., Zhang, M., Dai, Y., Xu, H. P., Wang, W. Q., Li, Q., Wang, Y., Wang, X. D., Mu, L., Ramenzani, J., Erwin, D. H., Angiolini, L., Zhang, F. F., Hou, Z. S., Chen, J., Zhang, X. Y., Zhang, S. H., Wu, Q., Pan, Y. X., Stephenson, M., and Mei, S. L.: Redefinition of the Global Stratotype Section and Point (GSSP) and new Standard Auxiliary Boundary Stratotype (SABS) for the base of Wuchiapingian Stage (Lopingian Series, Permian) in South China, Episodes, 47, 147–177, https://doi.org/10.18814/epiiugs/2023/023023, 2023.
Viaretti, M., Crippa, G., Brombin, V., Porta, G. D., Griesshaber, E., Jurikova, H., Posenato, R., Bottini, C., and Angiolini, L.: Duration and intensity of the Late Permian (early Wuchiapingian) cool climate episode: Sclerochemical evidence from brachiopod assemblages in Iran, Palaeogeogr. Palaeocl., 659, 112654, https://doi.org/10.1016/j.palaeo.2024.112654, 2025.
Wang, C. Y. and Dong, Z. C.: Permian conodonts from Suoxiyu in Cili County, Hunan, Acta Micropalacontologica Sinica, 8, 41–56, 1991 (in Chinese with English abstract).
Wang, C. Y. and Wang, Z. H.: Permian conodont biostratigraphy of China, Geol. Soc. Am. S., 187, 227–236, 1981a.
Wang, C. Y. and Wang, Z. H.: Permian conodonts from the Longtan Formation and Changxing Formation of Changxing, Zhejiang and their stratigraphical and palaeoecological significance, Selected Papers of 1st Convention Micropaleontological Society of China, 114–120, 1981b (in Chinese with English abstract).
Wang, W. Q., Garbelli, C., Zhang, F. F., Zheng, Q. F., Zhang, Y. C., Yuan, D. X., Shi, Y. K., Chen, B., and Shen, S. Z.: A high-resolution Middle to Late Permian paleotemperature curve reconstructed using oxygen isotopes of well-preserved brachiopod shells, Earth Planet. Sc. Lett., 540, 116245, https://doi.org/10.1016/j.epsl.2020.116245, 2020.
Wang, Z. H.: Permian–Lower Triassic conodonts of the Liangshan area, southern Shaanxi, Acta Palaeotologica Sinica, 17, 213–232, 1978 (in Chinese with English abstract).
Wignall, P. B., Sun, Y. D., Bond, D. P. G., Izon, G., Newton, R. J., Védrine, S., Widdowson, M., Ali, J. R., Lai, X. L., Jiang, H. S., Cope, H., and Bottrell, S. H.: Volcanism, Mass Extinction, and Carbon Isotope Fluctuations in the Middle Permian of China, Science, 324, 1179–1182, 2009.
Wu, G. C., Ji, Z. S., Lash, G. G., Yao, J. X., Zhang, S. W., and Li, Y. X.: Newly discovered Wuchiapingian to Olenekian conodonts from the Longgar area, southern Lhasa Terrane and their palaeobiogeographical implications, Lethaia, 54, 723–735, https://doi.org/10.1111/let.12435, 2021.
Xu, L. L., Huang, S. P., Liu, D. M., Liao, Z. W., Wu, K., Chen, M. K., Zhou, X. H., Zhang, Y. L., Liu, B., and Li, M.: Extensive accumulation of organic matter in the Late Permian Dalong Formation, Western Hubei Trough, Southern China, International Journal of Coal Geology, 302, 104727, https://doi.org/10.1016/j.coal.2025.104727, 2025.
Yang, B., Li, H. X., Wignall, P. B., Jiang, H. S., Niu, Z. J., Ye, Q., Wu, Q., and Lai, X. L.: Latest Wuchiapingian to Earliest Triassic Conodont Zones and δ13Ccarb Isotope Excursions from Deep-Water Sections in Western Hubei Province, South China, J. Earth Sci., 30, 1059–1074, https://doi.org/10.1007/s12583-019-1018-2, 2019.
Yang, J. H., Cawood, P. A., and Du, Y. S.: Voluminous silicic eruptions during late Permian Emeishan igneous province and link to climate cooling, Earth Planet. Sc. Lett., 432, 166–175, https://doi.org/10.1016/j.epsl.2015.09.050, 2015.
Yin, H. F., Zhang, K. X., Tong, J. N., Yang, Z. Y., and Wu, S. B.: The Global Stratotype Section and Point (GSSP) of the Permian-Triassic Boundary, Episodes, 24, 102–114, 2001.
Yong, R., Yang, H. Z., Wu, W., Yang, X., Yang, Y. R., and Huang, H. Y.: Controlling factors and exploration potential of shale gas enrichment and high yield in Permian Dalong Formation, northern Sichuan Basin, SW China, Petrol. Explor. Dev., 52, 285–300, https://doi.org/10.1016/S1876-3804(25)60567-2, 2025.
Yu, M. X., Zhao, J. H., Liu, K. Y., Hu, Q. H., Wu, W., Liu, Q. Y., Luo, C., Chen, Y., Ma, H. Y., and Jin, Z. J.: Paleoenvironment and organic matter enrichment in the Kaijiang–Liangping Trough across the Emeishan Large Igneous Province (ELIP), Mar. Petrol. Geol., 181, 107517, https://doi.org/10.1016/j.marpetgeo.2025.107517, 2025.
Yuan, D. X., Shen, S. Z., Henderson, C. M., Chen, J., Zhang, H., and Feng, H. Z.: Revised conodont-based integrated high-resolution timescale for the Changhsingian Stage and end-Permian extinction interval at the Meishan sections, South China, Lithos, 204, 220–245, https://doi.org/10.1016/j.lithos.2014.03.026, 2014.
Yuan, D. X., Shen, S. Z., and Henderson, C. M.: Revised Wuchiapingian conodont taxonomy and succession of South China, J. Paleontol., 91, 1191–1219, https://doi.org/10.1017/jpa.2017.71, 2017.
Yuan, D. X., Shen, S. Z., Henderson, C. M., Chen, J., Zhang, H., Zheng, Q. F., and Wu, H. C.: Integrative timescale for the Lopingian (Late Permian): A review and update from Shangsi, South China, Earth-Sci. Rev., 188, 190–209, https://doi.org/10.1016/j.earscirev.2018.11.002, 2019.
Yuan, D. X., Zhang, Y. C., Gorgij, M. N., Zhang, H., Angiolini, L., Crippa, G., Chen, J., and Shen, S. Z.: Lopingian biotic crisis and global correlation: Evidence from the Abadeh section, central Iran, Palaeogeography, Palaeoclimatology, Palaeoecology, 677, 113211, https://doi.org/10.1016/j.palaeo.2025.113211, 2025.
Zhang, K. X.: The Permo-Triassic conodont fauna in Changxing area, Zhejiang Province and its stratigraphic significance, Earth Sci., 12, 193–200, 1987.
Zhang, L. L., Zhang, N., and Xia, W. C.: Conodont succession in the Guadalupian–Lopingian boundary interval (upper Permian) of the Maoershan section, Hubei Province, China, Micopaleontology, 53, 433–446, 2007.
Zhang, L., Wu, J., Yuan, D. X., Forel, M. B., Chang, S., Khan, M. Z., Feng, Q. L., He, W. H., Ma, Q. F., Danelian, T., Caridroit, M., and Tsuyoshi, I.: Integrated Radiolarian and Conodont Biostratigraphy of the Middle to Late Permian Linghao Formation in Northwestern Guangxi, South China, Acta Geol. Sin.-Engl., 95, 1984–1997, https://doi.org/10.1111/1755-6724.14721, 2021.
Zhang, S. H., Yuan, D. X., and Shen, S. Z.: Global correlation of the Guadalupian–Lopingian transition and associated events using a quantitative conodont-based biostratigraphic scheme, Palaeogeogr. Palaeocl., 655, 112502, https://doi.org/10.1016/j.palaeo.2024.112502, 2024.
Zhang, S. H., Zhao, Y. Y., Shi, Y. K., Fang, Q., Wang, X. D., Fan, J. X., Zhang, Y. C., Yuan, D. X., Wang, Y., Zhang, F. F., Wu, H. C., Erwin, D. H., Marshall, C. R., and Shen, S. Z.: Global cooling drove diversification and warming caused extinction among Carboniferous–Permian fusuline foraminifera, Sci. Adv., 11, 2549, https://doi.org/10.1126/sciadv.adv2549, 2025a.
Zhang, X., Wei, H. Y., Wu, K., Gong, J. X., Wen, Y., and Mansour, A.: Marine redox evolutions and carbon isotope variations during the Guadalupian–Lopingian transition in the Yangtze Platform, South China, Palaeogeogr. Palaeocl., 660, 112681, https://doi.org/10.1016/j.palaeo.2024.112681, 2025b.
Zhao, X. Q., Liu, R., Wang, F. D., Li, Q., Su, C., Ding, J. M., Xiong, C. F., Li, W. T., Zhang, J. H., and Hou, K. L.: Determining the age of Guadalupian extinction by in situ uranium–lead geochronology in regard to middle Permian giant bivalve Alatoconchidae fossils in the Northwest margin of the South China Plate, Gondwana Res., 150, 405–418, https://doi.org/10.1016/j.gr.2025.10.008, 2026.
Zhong, Y. T., Mundil, R., Chen, J., Yuan, D. X., Denyszyn, S. W., Jost, A. B., Payne, J. L., He, B., Shen, S. Z., and Xu, Y. G.: Geochemical, biostratigraphic, and high-resolution geochronological constraints on the waning stage of Emeishan Large Igneous Province, Geol. Soc. Am., 132, 1969–1986, https://doi.org/10.1130/B35464.1, 2020.
Short summary
This study examines tiny fossils preserved in rocks from western Hubei and eastern Chongqing in South China to determine the age and continuity of Late Permian strata. By comparing fossil occurrences from several measured rock sections, we show that key rock layers were deposited continuously over time. Our results clarify when organic-rich rocks formed, helping to better understand regional geological history and providing useful time constraints for evaluating energy resource potential.
This study examines tiny fossils preserved in rocks from western Hubei and eastern Chongqing in...