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Experimental investigation of homogeneous vesicle formation and growth in hydrous silicate melts during decompression

水合硅酸盐熔体减压过程中均匀囊泡形成和生长的实验研究

基本信息

批准号：
336472361
负责人：
Professor Dr. Marcus Nowak
金额：
--
依托单位：
Forschungsbereich Mineralogie und Geodynamik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/336472361?language=en
关键词：
Experimental investigation homogeneous vesicle formation

项目摘要

Volcanic activity is essentially driven by dynamic degassing processes during ascent of volatile bearing magma. These processes often lead to explosive eruptions. The fundamental physico-chemical parameters that control the homogeneous formation of vesicles and their growth in a silicate melt are the initial concentration of dissolved volatiles, the supersaturation pressure (difference between the vapor pressure in the melt and the ambient pressure), the interfacial tension between melt and fluid (surface tension), the diffusivity of volatile components and the viscosity of the melt. The separation of volatiles from a homogeneous melt is associated with a complex interaction between initial formation, diffusive growth, expansion, coalescence and segregation of fluid vesicles. This phase separation is accompanied by a decrease in density and a change in the viscosity of the magma. Reliable formation and growth rates of H2O vesicles are important to improve phase separation and growth models, and to better understand dynamic degassing processes of volcanic eruptions. The aim of the project extension is the final systematic investigation of the formation and growth of H2O vesicles during continuous decompression in the simplified system SiO2-Al2O3-Na2O-K2O-H2O, starting from 200 MPa at 1123 K in hydrothermal autoclaves and from 200 MPa at 1323 K in the internally heated gas pressure vessel. Both devices are equipped with piezoceramic controlled valves for continuous decompression and allow fast cooling of the samples. The simplified SiO2-Al2O3-Na2O-K2O-H2O system is well suited for this project since H2O solubility and diffusion data as well as viscosity data, depending on the H2O content of the melts, are available over a wide pressure and temperature range. Considering experimental limitations, the expected fundamental results of this project prolongation will contribute to significantly improve future experimental studies on vesicle formation and degassing of hydrous melts with natural compositions. In addition, the expected experimental results together with computer-aided modelling will contribute substantially to a deeper understanding of magma degassing, which ultimately drives volcanic eruptions.

火山活动基本上是由含挥发分的岩浆上升过程中的动态脱气过程驱动的。这些过程经常导致爆炸性的喷发。控制微泡在硅酸盐熔体中均匀形成和生长的基本物理化学参数是溶解挥发物的初始浓度、过饱和压力(熔体中蒸气压力与环境压力之差)、熔体与流体之间的界面张力(表面张力)、挥发性组分的扩散率和熔体的粘度。挥发分从均相熔体中的分离与初始形成、扩散生长、膨胀、合并和流体小泡分离之间的复杂相互作用有关。这种相分离伴随着密度的降低和岩浆粘度的变化。可靠的H2O气泡的形成和生长速度对于改进相分离和生长模型以及更好地理解火山喷发的动态脱气过程是重要的。该项目扩展的目的是最终系统地研究在简化的SiO_2-Al_2O_3-Na_2O-K_2O-H_2O系统中连续减压过程中H2O小泡的形成和生长，在水热高压釜中从1123K的200 Mpa开始，在内热气体压力容器中从1323K的200 Mpa开始。这两个设备都配备了压电陶瓷控制阀，用于连续减压，并允许快速冷却样品。简化的SiO_2-Al_2O_3-Na_2O-K_2O-H_2O系统非常适合这个项目，因为可以在很宽的压力和温度范围内获得H2O的溶解度和扩散数据以及粘度数据，这取决于熔体中的H2O含量。考虑到实验的局限性，这一项目延长的预期基本结果将有助于显著改进未来关于天然成分含水熔体的气泡形成和脱气的实验研究。此外，预期的实验结果以及计算机辅助建模将大大有助于更深入地了解岩浆脱气，而岩浆脱气最终会驱动火山喷发。

项目成果

期刊论文数量（7）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

The effect of initial H2O concentration on decompression-induced phase separation and degassing of hydrous phonolitic melt

初始H2O浓度对水合酚醛熔体减压诱导相分离和脱气的影响

DOI：
10.1007/s00410-020-1659-2
发表时间：
2020
期刊：
Contributions to Mineralogy and Petrology
影响因子：
3.5
作者：
Allabar A;Salis Gross E;Nowak M
通讯作者：
Nowak M

High spatial resolution analysis of H2O in silicate glass using attenuated total reflection FTIR spectroscopy coupled with a focal plane array detector

DOI：
10.1016/j.chemgeo.2020.119833
发表时间：
2020-12-05
期刊：
CHEMICAL GEOLOGY
影响因子：
3.9
作者：
Allabar, Anja;Nowak, Marcus
通讯作者：
Nowak, Marcus

Vesicle shrinkage in hydrous phonolitic melt during cooling

水合酚醛树脂熔体冷却过程中的囊泡收缩

DOI：
10.1007/s00410-020-1658-3
发表时间：
2020
期刊：
Contributions to Mineralogy and Petrology. Beitrage Zur Mineralogie Und Petrologie
影响因子：
0
作者：
Allabar A;Dobson;Bauer CC;Nowak M
通讯作者：
Nowak M

Viscosity of Palmas-type magmas of the Paraná Magmatic Province (Rio Grande do Sul State, Brazil): Implications for high-temperature silicic volcanism

巴拉那岩浆省（巴西南里奥格兰德州）帕尔马斯型岩浆的粘度：对高温硅质火山作用的影响

DOI：
10.1016/j.chemgeo.2020.119981
发表时间：
2021
期刊：
Chemical Geology
影响因子：
3.9
作者：
Giordano D;Vona A;Gonzalez-Garcia D;Allabar A;Kolzenburg S;Polo L;De Assis Janasi V;Behrens H;De Campos C;De Cristofaro SP;Guimaraes LF;Nowak M;Müller D;Günther A;Masotta M;Roverato M;Romano C;Dingwell DB
通讯作者：
Dingwell DB

Message in a bottle: Spontaneous phase separation of hydrous Vesuvius melt even at low decompression rates

瓶中信：即使在低减压率下，含水维苏威火山也会自发相分离