气候变化领域集成服务门户(CCPortal): Settling of Immiscible Droplets: A Theoretical Model for the Missing Link Between Microscopic and Outcrop Observations

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DOI	10.1029/2019JB018829
	Settling of Immiscible Droplets: A Theoretical Model for the Missing Link Between Microscopic and Outcrop Observations
	Zhang Z.; Wu B.; Wang T.; Hui H.
发表日期	2020
ISSN	21699313
卷号	125 期号:6
英文摘要	Liquid immiscibility is a critical mechanism to diversify magma compositions. The physical separation of exsolved melt droplets is an essential process in generating new magmas. However, little attention has been paid to this physical process. In this study, we present a new model for segregation of immiscible melt droplets in which exsolution, settling, and coalescence are all considered. The separation of immiscible droplets is similar to that of crystals in magma when the discrete melt exsolves as large (millimeter-size) droplets and/or when the magma cools slowly. However, when immiscible melt droplets are small (micrometer-size) and/or magma cools rapidly, coalescence can significantly enhance their separation. The low interfacial tension between coexisting silicate melts leads to the exsolution of extremely small melt droplets. Furthermore, the high viscosity of silica-rich melt suppresses the coalescence of droplets. Consequently, the separation of highly viscous silica-rich melt droplets is slow but could have occurred in a slowly cooling magma such as the Skaergaard intrusion. By contrast, the coalescence rate of melt droplets with low viscosity is high. Iron-rich melt droplets, which have low viscosities, could have been separated from hydrous andesitic melts to form magnetite-apatite ore deposits at El Laco and Marcona. Furthermore, the viscosities of sulfide and carbonatitic melts are low. Therefore, immiscibility between sulfide and silicate melts may lead to the formation of magmatic sulfide deposits, and immiscibility between carbonatitic and silicate melts can support periodical eruptions of carbonatitic lava. ©2020. American Geophysical Union. All Rights Reserved.
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187819
作者单位	State Key Laboratory for Mineral Deposits Research and Lunar and Planetary Science Institute, School of Earth Sciences and Engineering, Nanjing University, Nanjing, China; Department of Geology and Geophysics, Yale University, New Haven, CT, United States; CAS Center for Excellence in Comparative Planetology, Hefei, China
推荐引用方式 GB/T 7714	Zhang Z.,Wu B.,Wang T.,et al. Settling of Immiscible Droplets: A Theoretical Model for the Missing Link Between Microscopic and Outcrop Observations[J],2020,125(6).
APA	Zhang Z.,Wu B.,Wang T.,&Hui H..(2020).Settling of Immiscible Droplets: A Theoretical Model for the Missing Link Between Microscopic and Outcrop Observations.Journal of Geophysical Research: Solid Earth,125(6).
MLA	Zhang Z.,et al."Settling of Immiscible Droplets: A Theoretical Model for the Missing Link Between Microscopic and Outcrop Observations".Journal of Geophysical Research: Solid Earth 125.6(2020).