The driving mechanisms of the carbon cycle perturbations in the late Pliensbachian (Early Jurassic)
The driving mechanisms of the carbon cycle perturbations in the late Pliensbachian (Early Jurassic)
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DOI：
10.1038/s41598-019-54593-1
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发表时间：
2019-12-05
影响因子：
4.6
通讯作者：
Schaltegger, Urs
中科院分区：
文献类型：
--
作者：
De Lena, Luis F.;Taylor, David;Schaltegger, Urs
早侏罗世（Pliensbachian晚期到Toarcian早期）是一个以气候波动和海洋缺氧为标志的时期。虽然早期Toarcian海洋缺氧事件（OAE）的原因已经得到了相当好的研究，但导致Toarcian OAE的事件，即Pliensbachian晚期事件，尚未得到很好的限制。晚Pliensbachian的生物和环境变化的驱动机制的情景范围从LIP火山（Karoo-Ferrar LIP），海洋停滞，海洋环流变化，轨道强迫。Karoo LIP和Pliensbachian晚期（Kunae-Carlottense菊石带）之间的时间关系进行了研究，以评估因果关系。我们提出了第一个绝对时间尺度上的Kunae和Carlottense区精确的高精度U-Pb地质年代学的基础上，和额外的geochemica I代理，为一系列的环境代理，如散装有机碳同位素组成，汞浓度，汞/TOC比，铼-锇同位素，以进一步探索它们的因果关系。这里提供的数据表明，卡鲁LIP和晚期Pliensbachian事件之间的因果关系不能维持。
The Early Jurassic (late Pliensbachian to earlyToarcian) was a period marked by extinctions, climate fluctuations, and oceanic anoxia. Although the causes of the early Toarcian Oceanic Anoxia Event (OAE) have been fairly well studied, the events that lead to the Toarcian OAE, i.e. the events in the late Pliensbachian, have not been well constrained. Scenarios of the driving mechanism of biotic and environmental changes of the late Pliensbachian have ranged from LIP volcanism (the Karoo-Ferrar LIP), ocean stagnation, and changing ocean circulation, to orbital forcing. The temporal relationship between the Karoo LIP and the late Pliensbachian (Kunae-Carlottense ammonite Zones) are investigated in an effort to evaluate a causal relationship. We present the first absolute timescale on the Kunae and Carlottense Zones based on precise high-precision U-Pb geochronology, and additional geochemica I proxies, for a range of environmental proxies such as bulk organic carbon isotope compositions, Hg concentration, and Hg/TOC ratios, and Re-Os isotopes to further explore their causal relationship. The data presented here show that causality between the Karoo LIP and the late Pliensbachian events cannot be maintained.