Quaternary explosive volcanism of the Cape Verde Archipelago: On- and offshore tephrostratigraphy

28个长达9米的重力岩心，是在M80/3号邮轮环绕和穿越佛得角群岛时收集的，总共包含205个火山灰层，记录了自晚更新世以来来自几个岛屿的高度爆炸性喷发。该项目旨在将岩芯之间的火山灰层与陆地上的冰盖岩层进行对比，以建立一个由绝对年龄测定支持的火山灰地层框架。然后，这些镁铁质、长英质和偶尔按成分分区的高碱性特弗利岩的地球化学、岩石学和火山学特征将被用来限制喷发过程、规模和频率以及岩浆演化条件的时空变化。一个特别的焦点将是明显丰富的镁铁质普林尼安喷发的产生。将我们关于第四纪晚期火山活动的结果与代表早期增长阶段的海山和岛屿侧翼的平行项目的数据进行比较，将有助于加深对大洋岛演化的理解。标志层的地层框架还将制约其他地质事件的年龄和速率(来自岛屿侧翼不稳定的浑浊洋流、撒哈拉尘埃的输入、成岩作用)以及海洋浮游生物的演化。

28 gravity cores up to 9 m long, collected during cruise M80/3 around and across the Cape Verde Archipelago, contain a total of 205 ash layers that document highly explosive eruptions from several of the islands since the late Pleistocene. This project aims to correlate ash layers between cores and with tephras on land in order to establish a tephrostratigraphic framework supported by absolute age dating. Geochemical, petrological and volcanological characterization of these mafic, felsic, and occasionally compositionally zoned, highly alkalic tephras will then be used to constrain temporal and spatial changes in eruption processes, magnitudes and frequencies as well as conditions of magmatic evolution. A special focus will be on the generation of the apparently abundant mafic Plinian eruptions. Comparison of our results on late Quarternary volcanism with data from a parallel project on seamounts and island flanks representing earlier growth stages will improve understanding of ocean island evolution. The stratigraphic framework of marker beds will also constrain ages and rates of other geological events (turbidity currents from island-flank instability, input of Saharan dust, diagenesis) as well as marine plankton evolution.