文章基本信息

标题：Isotopic evidence for continental ice sheet in mid-latitude region in the supergreenhouse Early Cretaceous
本地全文：下载
作者：Wu-Bin Yang ; He-Cai Niu ; Wei-Dong Sun 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2013
卷号：3
期号：1
DOI：10.1038/srep02732
语种：English
出版社：Springer Nature
摘要：Cretaceous represents one of the hottest greenhouse periods in the Earth's history, but some recent studies suggest that small ice caps might be present in non-polar regions during certain periods in the Early Cretaceous. Here we report extremely negative δ¹⁸O values of −18.12‰ to −13.19‰ for early Aptian hydrothermal zircon from an A-type granite at Baerzhe in northeastern China. Given that A-type granite is anhydrous and that magmatic zircon of the Baerzhe granite has δ¹⁸O value close to mantle values, the extremely negative δ¹⁸O values for hydrothermal zircon are attributed to addition of meteoric water with extremely low δ¹⁸O, mostly likely transported by glaciers. Considering the paleoaltitude of the region, continental glaciation is suggested to occur in the early Aptian, indicating much larger temperature fluctuations than previously thought during the supergreenhouse Cretaceous. This may have impact on the evolution of major organism in the Jehol Group during this period.