Trans-European ash plumes from the largest explosive volcanic eruptions: A tephra record from the East European Plain

最大的火山喷发产生的横贯欧洲的火山灰羽流：来自东欧平原的火山灰记录

• 批准号: 429662378
• 负责人: Dr. Carl-Dieter Garbe-Schönberg
• 金额: --
• 依托单位: Russian Foundation for Basic Research
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/429662378?language=en
• 关键词: Trans; European; ash; plumes; largest

One of the prerequisites of predicting future giant eruptions is the understanding of sizes and recurrence times of past similar events. The size of known explosive eruptions, however, is often poorly constrained as the majority of estimates are based solely on proximal deposits and do not consider voluminous veils of distal ash. Many ash plumes were dispersed by prevailing westerly winds towards the East European plain where tephra findings are ubiquitous and often associated with archaeological layers. In spite of importance of these tephra findings for the paleovolcanological, paleoclimate and archaeological research, those have never been studied with modern analytical tools. Tephra from only one locality, a cluster of Paleolithic sites of Kostenki-Borschevo (Middle Don River, Russia), was geochemically characterized and linked to the famous ~40 ka Campanian Ignimbrite eruption (Italy). About a hundred of other tephra sites dispersed in south Russian steppe from Penza and Tambov cities in the north to the Caucasus Mountains in the south remain unidentified and undated. Most of the tephras occur in tens of meters thick loess sequences, while a few tephras were found also in caves in the course of archaeological excavations. These tephras are likely derived from Mediterranean, Carpathian, Turkish, North Iranian and Caucasian eruptions and - once geochemically analyzed - could inform about earlier unknown volcanic events, their magnitudes and compositions of parent magma. In addition, geochemically fingerprinted and dated tephra layers provide an excellent tool for precise correlation and dating of disparate paleoenvironmental and archaeological archives. We propose a collaborative regional study of visible tephra layers in south Russia, which will include field work for tephra and sediments sampling, characterization of paleogeographic and paleoenviromental conditions of tephra deposition, and subsequent geochemical analysis (EMPA, LA-ICP-MS, TIMS) and dating (Ar-Ar, U/Pb, (U-Th)/He) of the tephras. The project team includes volcanologists and geochemists from Germany and Russia who have extensive experience in cooperative tephra studies, as well as young Russian paleogeographers and geomorphologists with an expertise in paleoenvironmental research in south Russia. We believe that joint efforts will permit us to (i) decipher a long-anticipated tephra record from southern Russia, (ii) delineate distribution of tephras from different sources, and (iii) estimate the ages and magnitudes of parent eruptions. The identified tephra layers will be integrated into the European tephra framework and contribute to the integration of the Russian paleoenvironmental data into the all-European context.

预测未来大喷发的先决条件之一是了解过去类似事件的规模和复发时间。然而，已知的爆炸性喷发的规模往往没有得到很好的限制，因为大多数估计只基于近端的沉积，而没有考虑远端火山灰的巨大面纱。许多火山灰羽状物被盛行的西风吹向东欧平原，那里到处都有非洲火山灰的发现，而且往往与考古层有关。尽管这些发现对古火山学、古气候和考古研究具有重要意义，但这些发现从未被现代分析工具研究过。只有一个地方的Tephra，即科斯滕基-Borschevo(俄罗斯顿河中游)旧石器时代遗址的集群，被进行了地球化学性质的表征，并与著名的~40ka坎帕尼亚伊尼姆布里特火山喷发(意大利)有关。从北部的彭扎和坦博夫到南部的高加索山脉，分布在俄罗斯南部草原上的大约100个其他Tephra遗址仍然身份不明，也没有确定日期。大多数冰盖出露在数十米厚的黄土层序中，在考古发掘过程中也在洞穴中发现了少数冰盖。这些冰盖很可能来自地中海、喀尔巴西亚、土耳其、伊朗北部和高加索火山喷发，一旦进行了地球化学分析，就可以了解早期未知的火山事件、其规模和母岩浆的成分。此外，经过化学指纹和年代测定的火山灰岩层为不同的古环境和考古档案的精确对比和年代测定提供了一个极好的工具。我们建议对俄罗斯南部可见的盖夫拉层进行区域合作研究，包括现场工作，进行盖夫拉和沉积物采样，描述盖弗拉沉积的古地理和古环境条件，以及随后的盖夫拉层的地球化学分析(EMPA，LA-ICPMS，TIMS)和定年(Ar-Ar，U/Pb，(U-Th)/He)。该项目团队包括来自德国和俄罗斯的火山学家和地球化学家，他们在合作的特弗拉研究方面拥有丰富的经验，以及年轻的俄罗斯古地理学家和地貌学家，他们对俄罗斯南部的古环境研究具有专门知识。我们相信，共同努力将使我们能够(I)破译期待已久的俄罗斯南部的特弗拉记录，(Ii)描绘来自不同来源的特弗拉的分布，以及(Iii)估计母火山喷发的年龄和强度。已确定的Tephra层将被纳入欧洲Tephra框架，并有助于将俄罗斯的古环境数据纳入全欧洲范围。