摘要
为进一步研究MORB斜长石熔体包裹体的形成机制,结合南大西洋中脊19°区域附近与Pet DB中MORB斜长石熔体包裹体数据,对Ca/Al值在斜长石熔体包裹体形成与改造过程中的变化规律进行讨论。结果显示,Ca/Al值可指示斜长石熔体包裹体形成过程中的化学分异作用、寄主结晶作用与扩散再平衡作用;当MORB斜长石熔体包裹体的Ca/Al>0.85(或0.80)时,熔体包裹体不能代表MORBs未分异的原始岩浆或结晶分异后的演化岩浆,SMAR19°研究区中MORB斜长石熔体包裹体的Ca/Al>1.0,其组分不能代表被捕获时的原始熔体。
Ca/Al ratio has direct indicating significance for the plagioclase-hosted melt inclusions research. Aim to further study the forming mechanism of plagioclase-hosted melt inclusions, this thesis has a research on plagioclase-hosted melt inclusions from South Mid-Atlantic ridge 19° MORB. Combining with the data of plagioclase-hosted melt inclusions in global petrological database（PetDB） , we discuss the variation characteristic of Ca/Al during the formation and modifica- tion proeessesof plagioclase-hosted melt inclusions. The results indicate that： （ 1 ） Ca/Al ratio has a direct potential to assess the chemical fraetionation, post-entrapment crystallization and diffusion processes ; （2） The melt inclusions with Ca/ Al〉0.85 （or 0.80）could not represent the primary or evaluation anhydrous MORB magma; （3）The composition of plagio- clase-hosted melt inclusions in SMAR19° with Ca/Al〉 1.0 could not represent the composition of melt at the time of inclu- sion trapping.
出处
《矿物岩石地球化学通报》
CAS
CSCD
北大核心
2016年第2期387-397,共11页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
中国大洋协会项目(DY125-12-R-01)
科技部重大国际合作项目(2006DFB21620)
国家自然科学基金项目(41322036)
