Microstructural evolution of silicate immiscible liquids in ferrobasalts
Microstructural evolution of silicate immiscible liquids in ferrobasalts
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DOI：
10.1007/s00410-019-1610-6
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发表时间：
2019-09-01
影响因子：
3.5
通讯作者：
Charlier, Bernard
中科院分区：
文献类型：
--
作者：
Honour, Victoria C.;Holness, Marian B.;Charlier, Bernard
一个不混溶的玄武质乳液的显微结构演化的实验研究表明，富铁液体形成均匀的成核液滴分散在一个连续的富硅液体，连同液滴上的斜长石，磁铁矿，辉石不均匀的成核。非均匀成核可能是由生长晶体周围的局部成分不均匀性促进的。富铁液滴在斜长石和磁铁矿上的润湿角均随温度的降低而增大。液滴粗化发生的扩散控制的增长和奥斯特瓦尔德熟化的组合，从聚结的贡献微不足道。在晶体生长过程中不混溶的富铁液体与晶粒的相互作用产生的特征微观结构可以潜在地用作完全结晶的天然样品中液体不混合的指示剂。在尺寸< 10 m的岩浆体中，不混溶的富铁液滴的重力驱动分离不太可能显着。
An experimental study of the microstructural evolution of an immiscible basaltic emulsion shows that the Fe-rich liquid forms homogeneously nucleated droplets dispersed in a continuous Si-rich liquid, together with droplets heterogeneously nucleated on plagioclase, magnetite, and pyroxene. Heterogeneous nucleation is likely promoted by localised compositional heterogeneities around growing crystals. The wetting angle of Fe-rich droplets on both plagioclase and magnetite increases with decreasing temperature. Droplet coarsening occurs by a combination of diffusion-controlled growth and Ostwald ripening, with an insignificant contribution from coalescence. Characteristic microstructures resulting from the interaction of immiscible Fe-rich liquid with crystal grains during crystal growth can potentially be used as an indicator of liquid unmixing in fully crystallised natural samples. In magma bodies < 10 m in size, gravitationally driven segregation of immiscible Fe-rich droplets is unlikely to be significant.