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DOI	10.1016/j.earscirev.2021.103665
	Processes in mushes and their role in the differentiation of granitic rocks
	Weinberg R.F.; Vernon R.H.; Schmeling H.
发表日期	2021
ISSN	00128252
卷号	220
英文摘要	The modification of magma through mixing or through assimilation of country rocks is commonly inferred from various chemical and isotopic features of magmatic rock suites and supported by a variety of field evidence, including features indicative of interaction between two magmas, disaggregation of solids in magma, and varied antecryst populations in volcanic and plutonic rocks. The increased recognition that mushes are important long-term reservoirs of magma, and that they play an important role in magmatic processes, suggests that the processes of magma mixing and country rock assimilation probably involves mushes. This paper investigates field evidence related to the behaviour of granitic mushes, in an attempt to understand their behaviour and assess their contribution to compositional variation in granitic rocks. Mushes, defined here as solids with interstitial melt, are permeable materials open to the invasion of extraneous melts. These can react with the crystalline framework and mix with or expel the original resident melt. This is the first step in either magma mixing or rock assimilation, and is recorded by ghost structures in migmatites, the loss of melt from a dyke to a mushy host rock, or patchy hybridization of microgranitoid enclaves (ME). The melt-filled porosity of mushes implies that they have an inherent physical weakness, which makes them subject to disaggregation and liquefaction through the combined effects of physical erosion, increased melt fraction, and pore pressure increase. As mushes disaggregate, solids may continue to react with their melt-rich surroundings. This is the second step in hybridization or assimilation, which tends to mask the history of exchange and the role of mushes. The history of granitic magmas starts with their extraction from a mushy migmatitic source or from a mushy cumulate, a process that controls their variable cargo of residual or cumulate crystals. These magmas may subsequently intrude, infiltrate and assimilate mushy wall-rocks or mushy xenoliths, or intrude, infiltrate and mingle with mushy mafic intrusions, forming mushy microgranitoid enclaves. The resulting magmas may themselves become temporary mushes, capable of being infiltrated by extraneous magmas before being liquefied and remobilized. Thus, mushes may play multiple and variable roles during the evolution of a single magma batch, facilitating magma mixing and wall-rock assimilation because mushes relax the energetic and physical constraints of these processes. Beyond providing opportunities for hybridization and assimilation, crustal mush columns provide multiple opportunities for magma batches to alternate between periods dominated by fractional crystallization and mush development, and periods dominated by remelting and mush remobilization, generating magmas with complex histories and varied geochemical signatures. © 2021 Elsevier B.V.
关键词	Assimilation Granite Hybridization Maficity Magma mixing Mingling Mush
英文关键词	assimilation efficiency; chemical composition; country rock; fractional crystallization; granite; igneous geochemistry; magma; magma chamber; migmatite; mixing; plutonic rock; volcanic rock
语种	英语
来源期刊	Earth Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/204168
作者单位	School of Earth Atmosphere and Environment, Monash University, Clayton, Victoria 3800, Australia; Department of Earth and Environmental Sciences, Macquarie University, Sydney, NSW 2109, Australia; Institute of Geosciences, Goethe University, Frankfurt, 60438, Germany
推荐引用方式 GB/T 7714	Weinberg R.F.,Vernon R.H.,Schmeling H.. Processes in mushes and their role in the differentiation of granitic rocks[J],2021,220.
APA	Weinberg R.F.,Vernon R.H.,&Schmeling H..(2021).Processes in mushes and their role in the differentiation of granitic rocks.Earth Science Reviews,220.
MLA	Weinberg R.F.,et al."Processes in mushes and their role in the differentiation of granitic rocks".Earth Science Reviews 220(2021).