Identification of catastrophic events recorded as resedimented deep marine deposits can be challenging because of multiple possible triggering mechanisms. This study investigates seismo-turbidites (STs) deposited in the Ionian Sea as a consequence of major historical earthquakes related to the Calabrian Arc subduction system. Taking advantage of the available sedimentological reconstructions, we focused our analysis on high-resolution X-ray fluorescence core scanner (XRF-CS), organic carbon and isotopic data to define geochemical signatures characterizing the ST units. The relationships between geochemical and sedimentological proxies were statistically tested using Pearson correlation and principal component analysis (PCA). Up to ∼78% of the total variance in the data set can be reduced to three principal components which identified four elemental ratio groups associated to the degree of terrestrial/coastal influence in each major depositional unit (i.e., pelagic, ST sandy stacked units, homogenites, tsunamite-seiche laminites, and tsunamite backwash). The sample score results were evaluated together with organic carbon data in order to assess geochemical variability throughout the composite turbidite structure in different basins settings. The basal parts of the ST contain coarse-grained sediment stacks whose sources can be traced back and sedimentary processes (surficial sediment erosion/massive slope failures) can be defined using geochemical data. The topmost parts of the STs exhibit a mixed compositional character suggesting basin-wide processes such as seiche oscillations and tsunami wave erosion/backwashing. The application of selected XRF-CS based elemental ratios as proxies in paleoseismological studies can help reconstruct the seismic history of a continental margin.

中文翻译：

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使用元素、有机碳和同位素数据破译地中海的同震沉积过程

由于多种可能的触发机制，识别记录为深海沉积物的灾难性事件可能具有挑战性。本研究调查了由于与卡拉布里亚弧俯冲系统相关的重大历史地震而沉积在爱奥尼亚海的地震浊积岩 (ST)。利用可用的沉积学重建，我们将分析重点放在高分辨率 X 射线荧光岩心扫描仪 (XRF-CS)、有机碳和同位素数据上，以定义表征 ST 单元的地球化学特征。使用 Pearson 相关和主成分分析 (PCA) 对地球化学和沉积学代理之间的关系进行了统计测试。数据集中高达 78% 的总方差可以减少为三个主要成分，这些成分确定了与每个主要沉积单元（即远洋、ST 砂质堆积单元、均质岩、海啸-seiche 叠层岩和海啸反冲）。样本评分结果与有机碳数据一起评估，以评估不同盆地环境中整个复合浊积岩结构的地球化学变异性。ST 的基底部分包含粗粒沉积物堆积，其来源可追溯，沉积过程（地表沉积物侵蚀/大规模斜坡崩塌）可使用地球化学数据进行定义。STs 的最顶端部分表现出混合的成分特征，表明存在整个盆地的过程，例如地震振荡和海啸波侵蚀/反冲。在古地震学研究中应用选定的基于 XRF-CS 的元素比率作为代理可以帮助重建大陆边缘的地震历史。