深熔过程中熔体成分与锆石行为模拟计算

CORC > 北京大学 > 地球与空间科学学院

	深熔过程中熔体成分与锆石行为模拟计算; Modelling of melt composition and zircon behaviour during anatexis
	王伟 ; 魏春景 ; 刘晓春 ; 赵越 ; 高亮 ; 娄玉行 ; 初航 ; 张颖慧
刊名	岩石学报
	2014
关键词	深熔作用熔体成分相平衡模拟锆石淡色花岗岩 Anatexis Melt composition Phase equilibrium modelling Zircon Leucogranite
英文摘要	发生深熔作用是高级变质作用的一个重要特征。深熔过程中产生的熔体可为淡色花岗岩提供潜在的源区;深熔过程中锆石的行为直接影响对变质锆石记年地质意义的理解。在含Zr体系下的相平衡模拟显示泥质成分深熔过程中产生熔体的成分在P-T空间中规律变化。温度升高时熔体Zr/Si值、Zr、FeO、MgO以及CaO等含量明显增加,压力较高时K2O含量也随温度升高而明显增加。Na2O含量随温度升高而降低,但随压力升高而增加。压力升高时Al/Si值显著升高。温度较高时Na/(Na+K)等值线较陡,减压熔融过程不会显著改变熔体Na/(Na+K)值,而升温减压过程以及近等压升温过程都会明显降低熔体Na/(Na+K)值。中压...; Anatexis is a common process accompanying high grade metamorphism. The melt produced by anatexis can be potential source for leucogranites; and the behavior of zircon during anatexis is crucial for understanding the geological meaning of metamorphic zircon. Phase equilibrium modelling for pelitic composition in the Zr-bearing system indicates that the modelled melt composition varies regularly in the P-T space. The Zr/Si ratio, Zr, FeO, MgO and CaO contents of the melt increase and the Na2O content decreases with increases in temperature. At high temperature the K2O content rises as the temperature increases. The Al/Si ratio and the Na2O content increase with increasing of the pressure. Decompression melting occurs at high temperature where the contours of the Na/(Na + K) ratio are steep will not lead to significant changes in the Na/(Na + K) ratio of the melt. But the processes involving decompression-heating and isobaric heating will remarkably decrease the Na/(Na + K) ratio of the melt. At medium pressure, the Fe/(Fe + Mg) ratio of the melt rises slowly with increases in temperature before the growth of garnet, which then effectively decreases the Fe/(Fe + Mg) ratio. The melt by solidus melting, muscovite and biotite dehydration melting has different compositions. The variation trend of the modelled melt compositions in the P-T space can help interpret the origin of leucogranites. The modelled relationships between zircon and major silicate mineral phases and melt indicate that prograde metamorphism is basically a zircon consuming process, and metamorphic zircon should mainly form during cooling and record the time of retrograde metamorphism. Loss of melt with less Zr content at low temperature can expand the zircon stability during prograde metamorphism. On the contrary, the melt loss at high temperature can decrease the zircon stability. A process similar to the fractional melting could most effectively expand the stability of zircon in the residuum.; SCI(E); 中文核心期刊要目总览(PKU); 中国科技核心期刊(ISTIC); 中国科学引文数据库(CSCD); 0; wangwei0521@gmail.com; 10; 3075-3084; 30
语种	中文
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/208033]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	王伟,魏春景,刘晓春,等. 深熔过程中熔体成分与锆石行为模拟计算, Modelling of melt composition and zircon behaviour during anatexis[J]. 岩石学报,2014.
APA	王伟.,魏春景.,刘晓春.,赵越.,高亮.,...&张颖慧.(2014).深熔过程中熔体成分与锆石行为模拟计算.岩石学报.
MLA	王伟,et al."深熔过程中熔体成分与锆石行为模拟计算".岩石学报 (2014).