Magma mixing process by fractal dimensions

1.对湄南河和大雪津火山进行了地质调查，特别是参考火山历史和包括镁铁质包裹体在内的非均质喷出物取样。2.用XRF和EPMA仪器对湄南河和大雪津火山的岩石和矿物进行了化学分析。斑晶边缘的化学分带表明，安山岩和英安岩岩浆是在岩浆房和岩浆岩的多阶段混合作用下喷发的。3. Me-akan火山非均质喷出物形态的分形维数在0.9 ~ 1.6之间，与岩浆的混合发展阶段和流动机制密切相关。火山碎屑岩喷发时，混合岩浆上升速率较大，处于湍流状态，分维较高。随着混合作用的进行，岩浆分维逐渐减小，长英质岩浆与镁铁质岩浆的完全均一化使分维结构消失，形成中间成分的岩浆，镁铁质包裹体对了解岩浆房和通道的混合过程具有重要作用。根据斜长石结构特征，将大雪津火山熔岩中的镁铁质包裹体分为三类。由于这些镁铁质包裹体的限制，提出了多阶段混合方案。

1.Geological survey of Me-akan and Taisetsu volcanoes was performed with special reference to the volcanic history and sampling for heterogeneous ejecta including mafic inclusions.2.Chemical analyzes of the rocks and minerals of Me-akan and Taisetsu volcanoes were carried out with XRF and EPMA achines. Chemical zonings at the rim of phenocrysts indicate that andesite and dacite magmas were erupted through the multi-stage magma mixing in magma chamber and conduit.3.Measured fractal dimensions of morphological patterns of heterogeneous ejecta from Me-akan volcano vary from 0.9 to 1.6, which are intimately correlated with mixing development stage and flow mechanism of magmas. In the case of pyroclastic eruptions, mixed magmas are in a turbulent state on account of higher ascending rate, which yields higher fractal dimensions. As mixing proceeds fractal dimensions decrease, and then perfect homogenization between felsic and mafic magmas causes the disappearance of the fractal structure to form intermediate composition magmas.Mafic inclusions have a key role in understanding the mixing process in magma chamber and conduit. The mafic inclusions in lavas from Taisetsu volcano are classified into three types based on the plagioclase texture. As a result of constraints for these mafic inclusions, multi-stage mixing scenario was proposed.