Early Jurassic (Toarcian) warming identified from lacustrine sediments of eastern Liaoning, China
Early Jurassic (Toarcian) warming identified from lacustrine sediments of eastern Liaoning, China
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DOI：
10.1017/s0016756820001235
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发表时间：
2020-11
影响因子：
2.3
通讯作者：
Qian Zhang;Enpu Gong;Yonglin Zhang;Changqing Guan
中科院分区：
文献类型：
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作者：
Qian Zhang;Enpu Gong;Yonglin Zhang;Changqing Guan
本研究的重点是中国辽宁东部的天师府盆地，该盆地充满了富含大型植物的中下侏罗统河湖沉积物。我们的目的是探索早侏罗世晚期的大陆性气候特征。对长梁子剖面（下侏罗统矿床上部）岩石样品的早—中侏罗世植物区系组成及有机质、总有机碳、总有机氮和硫的碳同位素比值进行了研究。从植物区系来看，辽东早侏罗世至中侏罗世总体气候湿润，但早侏罗世晚期气温升高。长梁子剖面沉积物表现出由浅湖相向深湖相的转变。有机碳同位素正偏移与这个古湖的加深有关，这被认为是由气候变暖引起的。花卉和同位素证据表明的早侏罗世晚期气候变暖与托阿尔纪时期海洋和大陆序列中其他地方记录的气候事件相对应，即所谓的托阿尔纪缺氧事件，并且可能与全球温室变暖加剧有关。这项研究提供了支持早侏罗世晚期全球变暖的新大陆数据。
This study focuses on the Tianshifu Basin, eastern Liaoning, China, which is filled with Lower–Middle Jurassic fluviolacustrine sediments rich in macroplants. Our aim is to explore the continental climate features of the late Early Jurassic period. The composition of the Early–Middle Jurassic flora and the carbon isotopic ratios of organic matter, total organic carbon, total organic nitrogen and sulphur of the rock samples from the Changliangzi section (the upper part of the Lower Jurassic deposits) have been investigated. Based on the flora, eastern Liaoning was generally characterized by temperate and humid conditions during the Early–Middle Jurassic period, but with rising temperatures during late Early Jurassic time. The sediments of the Changliangzi section show a transformation from shallow-lake facies to deep-lake facies. A positive organic carbon isotope excursion correlates with the deepening of this palaeolake, considered to be caused by climate warming. The late Early Jurassic climate warming indicated by floral and isotopic evidence corresponds to the climatic events recorded elsewhere in marine and continental sequences during the Toarcian Age, the so-called Toarcian Anoxic event, and may be associated with enhanced global greenhouse warming. This study provides new continental data supporting global warming during the late Early Jurassic period.