Effect of global warming at the CTBE on mid-latitude vegetation: Insights from palynology and organic-geochemical proxies.

为了更好地理解白垩纪中期极端温暖对大陆环境和生态系统的影响，对陆地古气候代理记录进行批判性评估至关重要。该初步研究将集中在盖诺曼—土鲁宁边界事件（CTBE）遗址的孢子-花粉组合和土源细菌生物标志物（MBT指数）上。该研究旨在(1)基于新开发的MBT生物标志物代理建立白垩纪热极大期开始时的大陆年平均温度（MAT）记录；(2)测试中纬度植物群落对与CTBE相关的气候和环境扰动的响应。法国东南部普罗旺斯盆地南部300米的连续剖面将允许以高时间分辨率研究中纬度陆地温度演变和相关植被响应，并将与现有的海洋温度演变代理数据进行详细比较。这些目标可望通过有机地球化学和孢粉学调查相结合的方法来实现。

A critical assessment of terrestrial palaeoclimate proxy records is essential to better understand the impact of mid-Cretaceous extreme warmth on continental environments and ecosystems. The proposed pilot study will focus on spore-pollen assemblages and soilderived bacteria biomarkers (MBT index) from a site covering the Cenomanian-Turonian boundary event (CTBE). The study is designed (1) to establish a continental mean annual temperature (MAT) record based on the newly developed MBT biomarker proxy across the onset of the Cretaceous Thermal Maximum and (2) to test the response of mid-latitude plant communities to the climatic and environmental perturbations associated with the CTBE. A continuous 300 m section from the Southern Provence Basin, SE France will allow to study mid-latitude terrestrial temperature evolution and the associated vegetation response at a high time resolution and will be compared in detail with existing marine-derived proxy data on temperature evolution. The achievement of these goals is expected from a combined approach including organic geochemical and palynological investigations.