Climatic ups and downs in a disturbed Jurassic world
Climatic ups and downs in a disturbed Jurassic world
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DOI：
10.1130/g31579.1
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发表时间：
2011-03-01
期刊：
影响因子：
5.8
通讯作者：
Durlet, Christophe
中科院分区：
文献类型：
--
作者：
Dera, Guillaume;Brigaud, Benjamin;Durlet, Christophe
侏罗纪世界的热带，温暖和稳定的气候经常受到地球科学家的挑战，特别是因为化石硬部件的氧同位素（δ O-18）已被用于重建海水的古温度历史。通过应用创新的“SiZer”（重大零交叉的衍生物）的统计方法，一个新编制的三角洲O-18数据库的侏罗纪，我们证明了发生的主要和多尺度三角洲O-18的变化主要与气候扰动。首次在O-18三角洲中发现了Toarcian和晚侏罗世期间的两个长期异常，并与大火成岩省的强烈火山作用相结合。这些结果支持一个强大的影响反复火山脉冲调制pCO（2），温度和极地冰盖体积在较长的时间。在较短的时间尺度上，13相对较快（0.5-1百万年）并确定了重大的升温和降温事件，其原因包括与仍有争议的机制有关的温室气体浓度的短暂波动。
The tropical, warm, and equable climate of the Jurassic world is regularly challenged by geoscientists, especially since oxygen isotopes (delta O-18) of fossil hardparts have been used to reconstruct the paleotemperature history of seawater. By applying the innovative "SiZer" (significant zero crossings of the derivatives) statistical approach to a newly compiled delta O-18 database for the Jurassic, we demonstrate the occurrence of major and multiscale delta O-18 changes mainly related to climate disturbances. For the first time, two long-term anomalies in delta O-18 are identified during the Toarcian and the Late Jurassic, in conjunction with intensive volcanism in large igneous provinces. These results support a strong influence of repeated volcanic pulses on the modulation of pCO(2), temperatures, and polar ice cap volumes over protracted periods. At shorter time scales, 13 relatively rapid (0.5-1 m.y.) and significant warming and cooling events are identified, the causes of which include transient fluctuations in greenhouse gas concentrations related to still-debated mechanisms.