External vs. internal forcing mechanisms in generating maar volcanoes

形成玛珥火山的外部与内部强迫机制

• 批准号: 200961086
• 负责人: Professor Dr. Hans-Ulrich Schmincke
• 金额: --
• 依托单位: Forschungseinheit Magmatische und Hydrothermale Systeme
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/200961086?language=en
• 关键词: External; vs.; internal; forcing; mechanisms

Maars are generally thought to result from magma-water interaction. This project aims at testing the hypothesis that expansion of exsolving CO2 is a major force in ascent and fragmentation of highly silicaundersaturated West Eifel magmas, many laden with mantle fragments, resulting in near-surface pyroclast-water interaction. In the less silica-undersaturated and C02-rich East Eifel magmas, environmental conditions (near-surface, permeable overlain by impermeable sediments) favor phreatomagmatic eruptions, deposits differing drastically from those in West Eifel maars. Excellent exposures will allow a detailed stratigraphic analysis of relevant deposits, single particle analysis including X-ray microtomography, scanning electron microscopy, XRF, LA-ICP-MS and electron microprobe. The geochemical and volcanological contrasts between East and West Eifel will allow a thorough evaluation of external versus internal forcing factors triggering and sustaining highly explosive eruptions that generate maars on one hand and unequivocal glass-rich phreatomagmatic deposits on the other. The results will aid assessing volcanic hazards from explosive eruptions.

Maars通常被认为是岩浆-水相互作用的结果。该项目旨在检验这一假设，即出溶CO2的膨胀是高度silicaundersaturated西艾菲尔岩浆上升和破碎的主要力量，其中许多岩浆充满地幔碎片，导致近地表火山碎屑-水相互作用。在较少的二氧化硅不饱和和CO2丰富的东艾弗尔岩浆，环境条件（近地表，渗透性不渗透的沉积物覆盖）有利于phreatomagmatic火山喷发，存款从西艾弗尔玛耳火山大不相同。良好的暴露将允许对相关矿床进行详细的地层分析、单颗粒分析，包括X射线显微断层摄影术、扫描电子显微镜、XRF、LA-ICP-MS和电子微探针。东，西艾菲尔之间的地球化学和火山对比将允许外部与内部的强迫因素触发和维持高爆炸性喷发，一方面产生玛耳和明确的富含玻璃的phreatomagmatic存款的另一方面进行彻底的评估。研究结果将有助于评估火山爆发的危险。