摘要
三叠纪—侏罗纪之交(Triassic-Jurassic boundary,TJB)发生了三叠纪末的生物大灭绝(end-Triassic mass extinction,ETE),海洋和陆地生态系统都发生了不同程度的崩溃。而在陆地生态系统中,植物群首当其冲,但是该时段的植物群变化的详细数据还相对缺乏。本文在新疆准噶尔盆地南缘郝家沟剖面TJB地层系统采样研究,来揭示该过程的植物群响应。根据孢粉属种组成及含量变化划分了3个孢粉组合,对古气候进行了重建。结果表明,准噶尔盆地南缘TJB的气候演变经历了湿热—湿冷—干热的转换过程。同时对ETE和TJB两个重要界线及灭绝发生的期次关系进行了讨论,由孢粉数据结合前人植物大化石、有机碳同位素地层曲线、生物标志化合物和Hg/TOC全球对比的结果,指示ETE和TJB可能分别位于郝家沟组43层底附近和八道湾组49层底附近;并推测三叠纪末陆地植被的灭绝在高纬度的准噶尔盆地记录到3个期次。在ETE与TJB之间地层中发现了与全球多处记录到的孢子含量激增一致的现象,推测该时期陆地生态系统的波动具有全球性。
The end-Triassic mass extinction(ETE)occurred at the Triassic-Jurassic boundary(TJB),and both marine and terrestrial ecosystems have collapsed. The floras are the first to collapse in the terrestrial ecosystems. However, detailed data on the changes of floras during this period are relatively rare. In order to reveal the response of floras, we systematically sampled and studied the TJB formation in the Haojiagou section in the southern Junggar Basin, Xinjiang. In this study, three palynological assemblages are divided according to the species composition and content variation of palynological genus, and the paleoclimate is reconstructed. We found that the paleoclimate in the southern Junggar Basin during the TJB fluctuated from wet-hot to wet-cold, and then to dry-hot characters. Meanwhile, the two important boundaries of ETE and TJB, and stages of the extinction were discussed. The palynological evidence and previous studies of global comparison of carbon isotope stratigraphy, Hg/TOC, the biomarker and plants fossils suggest that ETE may be at around the bottom of bed 43 in the Haojiagou Formation and TJB at around the bottom of bed 49 in the Badaowan Formation. It is inferred that there are three stages of the terrestrial flora extinctions around ETE in the high-latitude Junggar Basin. Because the “spores spike” in beds between ETE and TJB is consistent with the records in several classic sections across the world, it is speculated that the collapse of terrestrial ecosystem was on a global scale.
作者
张新智
方琳浩
吴涛
苗运法
张明震
王雪莲
吕沛宗
何秀娟
邱若原
杨涵
任嘉豪
Zhang Xinzhi;Fang Linhao;Wu Tao;Miao Yunfa;Zhang Mingzhen;Wang Xuelian;LüPeizong;He Xiujuan;Qiu Ruoyuan;Yang Han;Ren Jiahao(College of Geoscience,China University of Petroleum(Beijing),Beijing 102249;State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum(Beijing),Beijing 102249;Research Institute of Exploration and Development,Xinjiang Oilfield Company,PetroChina,Karamay,Xinjiang 843000;Northwest Institute of Ecology and Environmental Resources,Chinese Academy of Science,Lanzhou 730000;Key Laboratory of Cenozoic Geology and Environment,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029;Key Laboratory of Earthquake Geodesy,CEA,Wuhan 430071;School of Earth and Space Sciences,Peking University,Beijing 100871)
出处
《地质科学》
CAS
CSCD
北大核心
2022年第4期1161-1176,共16页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
国家自然科学基金项目(编号:41502024)
中国石油大学(北京)青年拔尖人才项目(编号:2462014YJRC027)资助。
关键词
准噶尔盆地
三叠系—侏罗系
孢粉
三叠纪末生物灭绝
古气候
Junggar Basin
Triassic-Jurassic boundary
Pollen records
End-Triassic mass extinction
Paleoclimate
