Simulating maar–diatreme volcanic systems in bench-scale experiments
Simulating maar–diatreme volcanic systems in bench-scale experiments
复制标题
在实验室规模实验中模拟 maar-diatreme 火山系统
DOI：
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发表时间：
2015
影响因子：
2.7
通讯作者：
B. Zimanowski
中科院分区：
文献类型：
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作者：
R. Andrews;J. D. White;T. Dürig;B. Zimanowski
Maar-diatreme火山爆发并不完全了解，对它们所涉及的过程的解释已经争论了几十年。这项研究扩展了以前在玛珥火山系统上进行的实验室规模的模拟实验，并试图将结果扩展到野外规模的实验和天然火山系统，以产生玛珥火山的重建工具包。这些实验通过多种机制产生了复杂的沉积物，这些沉积物与天然岩浆岩沉积物中的许多特征相匹配。运行包括更深的单一爆炸，一系列下降的离散爆炸，和一系列上升的爆炸。本研究表明，碎屑射流开始和diatreme形成涉及多种类型的颗粒喷泉在不同的初始条件下产生的diatreme存款。不可能从最终沉积物中推断出多次爆炸系列中单个爆炸的能量。爆炸序列的沉积记录可以从后退沉积物与火山喷出物边缘物质的比例、最终火山口的大小以及附属地层的倾覆或滑塌程度来确定。从数量上看，较深的爆炸涉及到一个大致相等的分割成火山口挖掘能源与少年材料的质量运动的能量，而较浅的爆炸消耗更大比例的能量在火山口挖掘。补充材料：5个视频文件，12个数字和3个表格可在http://www.geolsoc.org.uk/SUP18890上查阅。
Maar–diatreme eruptions are incompletely understood, and explanations for the processes involved in them have been debated for decades. This study extends bench-scale analogue experiments previously conducted on maar–diatreme systems and attempts to scale the results up to both field-scale experimentation and natural volcanic systems to produce a reconstructive toolkit for maar volcanoes. These experimental runs produced via multiple mechanisms complex deposits that match many features seen in natural maar–diatreme deposits. The runs include deeper single blasts, series of descending discrete blasts, and series of ascending blasts. Debris-jet inception and diatreme formation are indicated by this study to involve multiple types of granular fountains within diatreme deposits produced under varying initial conditions. It is not possible to infer the energies of single blasts in multiple-blast series from the final deposits. The depositional record of blast sequences can be ascertained from the proportion of fallback sedimentation versus maar ejecta rim material, the final crater size and the degree of overturning or slumping of accessory strata. Quantitatively, deeper blasts involve a roughly equal partitioning of energy into crater excavation energy versus mass movement of juvenile material, whereas shallower blasts expend a much greater proportion of energy in crater excavation. Supplementary materials: Five video files, 12 figures and three tables are available at http://www.geolsoc.org.uk/SUP18890.