上扬子晚二叠世吴家坪期古海洋氧化还原环境重建【“华南古大陆演化及其资源环境效应”专辑】
- 雍茹男1,
- 孙诗1, ,
- 陈安清2,
- 侯明才1,
- 李夔州3,
- 李乾1,
- 黄光辉1,
- 李雯2,
- 解昊4,
- 陈洪德4
- 收稿日期:
2024-10-09
- 网络出版日期:
2024-11-22
摘要: 【目的】瓜德鲁普末期生物灭绝之后,生物多样性在晚二叠世开始逐步恢复,但关于该时期生物复苏与古海洋氧化还原变化之间的具体联系尚不清楚。【方法】为进一步确定晚二叠世浅海氧化还原状态和演变特征,选取上扬子北缘具高分辨率时间框架约束的上寺剖面吴家坪阶地层作为研究对象,开展了详细的沉积学和地球化学研究,重建了晚二叠世吴家坪期海洋氧化还原环境。【结果】研究结果表明:(1)根据碳同位素和铈异常指标的系统变化,可以将整个研究序列分为3个阶段:阶段Ⅰ碳同位素相对正偏,海水偏向氧化环境;阶段Ⅱ碳同位素迅速负偏,海洋转变为缺氧环境;阶段Ⅲ碳同位素整体较为稳定,海水缺氧程度减弱。(2)在全球不同地区均可以观察到吴家坪阶由早期的碳同位素早期正偏到中期负偏的变化趋势,揭示该时期的碳循环波动具有全球性。(3)吴家坪早期,生物逐渐复苏导致海洋初级生产力提高和光合作用增强,同时凉爽气候利于洋流循环和氧气交换,该时期整体处于贫氧-氧化环境;吴家坪中期开始,随着气候转暖和晚古生代冰期消亡,海洋通风减弱和海平面上升共同驱动最小含氧带的显著扩张,海洋转变为缺氧环境。【结论】重建了研究区晚二叠世吴家坪期浅海环境的氧化还原演化过程,并结合同期相关生命环境指标,进一步探讨该时期的碳循环波动、氧化还原变化及其与生物演化之间的深层联系。
Reconstruction of paleo-ocean redox environment during the Late Permian Wuchiapingian, Upper Yangtze
- Received Date:
2024-10-09
- Available Online:
2024-11-22
Abstract: [Objective] After the End-Guadalupian extinction, the global biodiversity gradually recovered in the Late Permian. However, the specific relationship between biological recovery during this period and paleo-ocean redox condition remains unclear. [Method] To further determine the evolution characteristics of the redox condition of shallow waters in the Late Permian, the Wujiaping Formation in the Shangsi section of the northern margin of the Yangtze Block with high-resolution time frame constraints was selected as the research object. Detailed sedimentological and geochemical studies have been employed to reconstruct the marine redox environment of the Wujiaping Formation in the Late Permian.[Results] The results indicate that: (1) Based on the systematic changes of carbon isotope and cerium anomaly indicators, the entire geochemical profiles can be divided into three stages: Stage I exhibits a relatively positive carbon isotope shift, and the seawater tends towards an oxic environment; stage II shows a rapidly negative carbon isotope shift, and the ocean transitions to an anoxic environment; in stage III, the carbon isotopes are generally stable, and the anoxic conditions wane. (2) The global carbon cycle fluctuations during the Wuchiapingian can be observed evidently in various regions worldwide, and the carbon isotope compositions transform from a positive shift in the early period to a negative bias in the mid-period. (3) In the early Wuchiapingian, the gradual recovery of marine biota in the photic zone led to increased primary productivity and photosynthesis. During this time, the cool climate facilitated current circulation and atmosphere-ocean oxygen exchange, leading to an overall oxic environment; With the subsequent warming climate and the demise of the Late Paleozoic Ice Age, the weakening of ocean ventilation and the rise of sea level jointly drove the significant expansion of the oxygen minimum zone, transforming the ocean into an anoxic environment. [Conclusion] This study aimed to reconstruct the redox evolution process of the shallow marine environment during the Late Permian Wuchiapingian. Combining relevant environmental indicators, further explores the carbon cycle fluctuations, redox condition, and their deep connections with biological evolution during this period.
雍茹男, 孙诗, 陈安清, 侯明才, 李夔州, 李乾, 黄光辉, 李雯, 解昊, 陈洪德. 上扬子晚二叠世吴家坪期古海洋氧化还原环境重建【“华南古大陆演化及其资源环境效应”专辑】[J]. 沉积学报. doi: 10.14027/j.issn.1000-0550.2024.119
Reconstruction of paleo-ocean redox environment during the Late Permian Wuchiapingian, Upper Yangtze[J]. Acta Sedimentologica Sinica. doi: 10.14027/j.issn.1000-0550.2024.119
Citation: |
Reconstruction of paleo-ocean redox environment during the Late Permian Wuchiapingian, Upper Yangtze[J]. Acta Sedimentologica Sinica. doi: 10.14027/j.issn.1000-0550.2024.119
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