Systematic variations in the eruptive history of the Christiana-Santorini-Kolumbo volcanic field (Greece) - The IODP Expedition 398 tephra time series and its implications

克里斯蒂安娜-圣托里尼-科伦博火山场（希腊）喷发历史的系统变化 - IODP Expedition 398 tephra 时间序列及其含义

• 批准号: 527924707
• 负责人: Privatdozent Dr. Steffen Kutterolf
• 金额: --
• 依托单位: Forschungseinheit Magmatische und Hydrothermale Systeme
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/527924707?language=en
• 关键词: Systematic; variations; eruptive; history; Christiana

During IODP Expeditions 398 the objectives were to study the volcanic record of the central Hellenic island arc to document the links and feedbacks between volcanism/magmatism, crustal tectonics and sea level, and to investigate the processes and products of shallow submarine eruptions of silicic magma. Reconstructing the subsidence history of the southern Aegean Sea, and searching for deep life inside and outside of Santorini caldera, were additional objectives. The expedition drilled ten sites originally proposed, plus two extra sites that were requested during the expedition. Outside of Santorini caldera, drilling penetrated the thick basin fills of the crustal rift system hosting the Christiana-Santorini-Kolumbo volcanic field, identifying numerous pumice and ash layers, some known from onland and others hitherto unknown, pushing back the onset of volcanism in the area into the early Pleistocene or even Pliocene. Huge events of mass wasting into the basins, accompanied by very high sedimentation rates, were also documented. These basin sites served to groundtruth the seismic stratigraphy of the basins and to open the way to unravelling relationships between volcanic activity and crustal rift pulses. Two sites of condensed sequences on the basin margins served to sample many volcanic layers within the detailed age-depth constraints provided mainly by biostratigraphy. Drilling inside Santorini caldera penetrated to ~120 mbsf and yielded a detailed tephra record of the history of the Kameni islands. Tephra deposits from Exp. 398 complemented by tephras found on land provide the unique opportunity to investigate and compare the history of highly explosive volcanic activity of the Christiana-Santorini-Kolumbo volcanic field in the heart of Southern Europe, including one of the most famous and most active volcanoes in our neighborhood. This project focuses therefore on the ~1200 volcanic horizons derived from highly explosive eruptions during the Pliocene and Quaternary and found in the cores. Geochemical, petrological and volcanological approaches for tephra and sediment characterization will be used to quantitatively and qualitatively decrypt their provenance and the eruption succession. Additionally, absolute age dating will improve and confirm the existing age models since robust age models are needed to study the temporal and spatial changes in eruption processes, magnitudes and frequencies of large volcanic eruptions. The herewith-established compositional data and eruptive time series will serve as base to address questions regarding recurrence rates and cyclicities, and compare them with external controlling mechanism like tectonics and sea level changes. Recovered sediments will also facilitate to investigate the temporal and quantitative characterization of the sediment composition in the basins of the Aegean Sea in relation to the volcaniclastic input and answer the question how this may be connected to the basin evolution.

在IODP探险期间398目的是研究中央希腊岛弧的火山记录，以记录火山/岩浆，地壳构造与海平面之间的联系和反馈，并研究硅岩浆浅层潜艇爆发的过程和产物。重建南部爱琴海的沉降历史，并在圣托里尼火山口附近和外部寻找深厚的生活，这是其他目标。探险队钻了十个最初提议的地点，以及在探险期间要求的两个额外地点。在圣托里尼火山口外，钻探穿透了托管克里斯蒂安娜·塞托琳 - 科洛姆博火山田的厚盆地填充物，鉴定了许多来自Onland的浮石和灰烬层，其中一些人已知来自Onland和其他迄今未知的层，将其推向了早期的Pleistecene或Pleistecenecene的早期。还记录了大规模浪费的大量事件，并伴随着非常高的沉积率。这些盆地地点为盆地的地震地层形成，并为揭开火山活动与地壳裂谷脉冲之间的关系开辟道路。盆地边缘上的两个凝结序列的位点可在主要由生物地层学提供的详细年龄深度约束中采样许多火山层。 Santorini火山口内的钻探渗透到约120 mbsf，并产生了Kameni群岛历史的详细记录。 tephra矿床。 398在陆地上发现的Tephras补充提供了独特的机会，可以调查和比较南欧中心的Christiana-Santorini-Kolumbo火山场高度爆炸性的火山活动的历史，其中包括我们社区中最著名，最活跃的火山之一。因此，该项目着重于在上新世和第四纪期间从高度爆炸性喷发中衍生出的〜1200个火山范围，并在核心中发现。用于tephra和沉积物表征的地球化学，岩石学和火山学方法将用于定量和定性地解密其出处和喷发继承。此外，由于需要健壮的年龄模型来研究大型火山喷发的喷发过程，大小和频率的时间变化，因此绝对年龄的年龄将改善和确认现有年龄模型。此后，建立的构图数据和爆发时间序列将作为解决复发率和周期性的问题的基础，并将它们与外部控制机制（如构造和海平面变化）进行比较。回收的沉积物还将有助于研究爱琴海盆地中与火山碎屑输入相关的沉积物组成的时间和定量表征，并回答该问题如何与盆地进化有关。