Browsing by Author "Ye, Qin"

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    Mid-latitudinal habitable environment for marine eukaryotes during the waning stage of the Marinoan snowball glaciation
    Song, Huyue; An, Zhihui; Ye, Qin; Stueken, Eva E.; Li, Jing; Hu, Jun; Algeo, Thomas J.; Tian, Li; Chu, Daoliang; Song, Haijun; Xiao, Shuhai; Tong, Jinnan (Nature Portfolio, 2023-04)
    Based on geochemical and paleontological data, this study shows that habitable open-oceans extended to mid-latitude coastal oceans during the waning stage of the Marinoan snowball Earth, offering refugia for benthic photosynthetic eukaryotes During the Marinoan Ice Age (ca. 654-635 Ma), one of the 'Snowball Earth' events in the Cryogenian Period, continental icesheets reached the tropical oceans. Oceanic refugia must have existed for aerobic marine eukaryotes to survive this event, as evidenced by benthic phototrophic macroalgae of the Songluo Biota preserved in black shales interbedded with glacial diamictites of the late Cryogenian Nantuo Formation in South China. However, the environmental conditions that allowed these organisms to thrive are poorly known. Here, we report carbon-nitrogen-iron geochemical data from the fossiliferous black shales and adjacent diamictites of the Nantuo Formation. Iron-speciation data document dysoxic-anoxic conditions in bottom waters, whereas nitrogen isotopes record aerobic nitrogen cycling perhaps in surface waters. These findings indicate that habitable open-ocean conditions were more extensive than previously thought, extending into mid-latitude coastal oceans and providing refugia for eukaryotic organisms during the waning stage of the Marinoan Ice Age.
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    Systematic paleontology, acritarch biostratigraphy, and delta C-13 chemostratigraphy of the early Ediacaran Krol A Formation, Lesser Himalaya, northern India
    Xiao, Shuhai; Jiang, Ganqing; Ye, Qin; Ouyang, Qing; Banerjee, Dhiraj M.; Singh, Birendra P.; Muscente, A. D.; Zhou, Chuanming; Hughes, Nigel C. (Cambridge University Press, 2022)
    Acritarch biostratigraphic and delta C-13 chemostratigraphic data from the Krol A Formation in the Solan area (Lesser Himalaya, northern India) are integrated to aid inter-basinal correlation of early-middle Ediacaran strata. We identified a prominent negative delta C-13 excursion (likely equivalent to EN2 in the lower Doushantuo Formation in the Yangtze Gorges area of South China), over a dozen species of acanthomorphs (including two new species-Cavaspina tiwariae Xiao n. sp., Dictyotidium grazhdankinii Xiao n. sp.), and numerous other microfossils from an interval in the Krol A Formation. Most microfossil taxa from the Krol A and the underlying Infra-Krol formations are also present in the Doushantuo Formation. Infra-Krol acanthomorphs support a correlation with the earliest Doushantuo biozone: the Appendisphaera grandis-Weissiella grandistella-Tianzhushania spinosa Assemblage Zone. Krol A microfossils indicate a correlation with the second or (more likely, when delta C-13 data are considered) the third biozone in the lower Doushantuo Formation (i.e., the Tanarium tuberosum-Schizofusa zangwenlongii or Tanarium conoideum-Cavaspina basiconica Assemblage Zone). The association of acanthomorphs with EN2 in the Krol Formation fills a critical gap in South China where chert nodules, and thus acanthomorphs, are rare in the EN2 interval. Like many other Ediacaran acanthomorphs assemblages, Krol A and Doushantuo acanthomorphs are distributed in low paleolatitudes, and they may represent a distinct paleobiogeographic province in east Gondwana. The Indian data affirm the stratigraphic significance of acanthomorphs and delta C-13, clarify key issues of lower Ediacaran bio- and chemostratigraphic correlation, and strengthen the basis for the study of Ediacaran eukaryote evolution and paleobiogeography. UUID: http://zoobank.org/5289fdb2-0e49-4b3b-880f-f5b21acab371.