摘要
卡尼期湿润幕(Carnian Pluvial Episode,缩写为CPE,约234～232 Ma)是中生代最重要的极热事件之一,也是近十年来地学领域的一大研究热点.近年来,学界应用多种指标对CPE的陆相响应开展了细致的研究,在气候干湿变换、触发机制和生物多样性变化等方面取得了诸多新认识.本文系统梳理了 CPE期间的陆相沉积特征、孢粉化石记录、地球化学信号与陆地生物面貌,对新近的研究进展进行了回顾与总结.目前,卡尼期大部分陆相沉积的年代约束证据较弱,开展综合地层学工作是不同盆地精细对比的基础.在CPE全球水循环加快的背景下,陆地不同地区的干湿气候变化可能具有较大差异性.陆相地层的高分辨率多指标分析将为精细约束CPE的触发及结束过程起到关键作用.
Abstract
The Carnian Pluvial Episode(CPE,ca.234～232 Ma)is one of the most significant hyperthermal events in the Mesozoic Era and has also been a pivotal topic in geosciences over the past decade.In recent years,geologists have successively conducted comprehensive research on the terrestrial response of the CPE through multiple proxies,resulting in a wealth of new insights into climate change,triggering mechanisms and biodiversity changes.This paper presents a summary of the continental sedimentation characteristics,pollen record,geochemical signals and terrestrial biological features during the CPE.The CPE is characterized by an increase in freshwater lacustrine,deltaic,and coal-bearing sediments,accompanied by an absence of evaporites.The diversity of terrestrial hygrophytic plants and freshwater algae significantly increased during the CPE,indicating a remarkable enhancement of the hydrological cycling.However,notable arid climates developed in regions such as the Central European Basin,UK,Brazil and parts of Antarctica,possibly showing that regional climate variation was not uniform under high-temperature regimes.Some palynological records demonstrating a wet-dry transition are not synchronous with the end of the carbon isotope negative excursion,requiring a definition of the end of the CPE to avoid confusion in comparing different stages of this event.Major terrestrial life changes during the CPE included the extinction of certain tetrapod groups,the radiation of dinosaurs,bennettitaleans and conifers,the origin of crocodiles and mammals,and the first appearance of amber inclusions.However,accurately reconstructing the relationship between biota and the environment during the CPE remains challenging due to the incompleteness of the fossil record and the low precision of age constraints in terrestrial sediments.Therefore,this review highlights the need for comprehensive stratigraphic work to facilitate accurate cross-basin correlation.Moreover,considering the intensified hydrological cycle during the CPE,it is likely that regional climate variation was not uniform.High-resolution analyses of continental sediments are anticipated to be crucial in elucidating the mechanisms that triggered and terminated the CPE.
维普
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