Grain to outcrop-scale frozen moments of dynamic magma mixing in the syenite magma chamber, Yelagiri

来源 :Geoscience Frontiers | 被引量 : 0次 | 上传用户:shkarenwang
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Magma mixing process is unusual in the petrogenesis of felsic rocks associated with alkaline complex worldwide.Here we present a rare example of magma mixing in syenite from the Yelagiri Alkaline Complex,South India.Yelagiri syenite is a reversely zoned massif with shoshonitic(Na2O+K2O=5-10 wt.%,Na2O/K2 O=0.5-2,TiO2<0.7 wt.%) and metaluminous character.Systematic modal variation of plagioclase(An11-16Ab82-88),K-feldspar(Or27-95Ab5-61),diopside(En34-40Fs11-18Wo46-49),biotite,and Ca-amphibole(edenite) build up three syenite facies within it and imply the role of in-situ fractional crystallization(FC).Evidences such as(1) disequilibrium micro-textures in feldspars,(2) microgranular mafic enclaves(MME) and(3) synplutonic dykes signify mixing of shoshonitic mafic magma(MgO=4-5 wt.%,SiO2=54-59 wt.%,K2O/Na2 O=0.4-0.9) with syenite.Molecular-scale mixing of mafic magma resulted disequilibrium growth of feldspars in syenite.Physical entity of mafic magma preserved as MME due to high thermal-rheological contrast with syenite magma show various hybridization through chemical exchange,mechanical dilution enhanced by chaotic advection and phenocryst migration.In synplutonic dykes,disaggregation and mixing of mafic magma was confined within the conduit of injection.Major-oxides mass balance test quantified that approximately 0.6 portions of mafic magma had interacted with most evolved syenite magma and generated most hybridized MME and dyke samples.It is unique that all the rock types(syenite,MME and synplutonic dykes) share similar shoshonitic and metaluminous character; mineral chemistry,REE content,coherent geochemical variation in Harker diagram suggest that mixing of magma between similar composition.Outcrop-scale features of crystal accumulation and flow fabrics also significant along with MME and synplutonic dykes in syenite suggesting that Yelagiri syenite magma chamber had evolved through multiple physical processes like convection,shear flow,crystal accumulation and magma mixing. Magma mixing process is unusual in the petrogenesis of felsic rocks associated with alkaline complex worldwide. Here we present a rare example of magma mixing in syenite from the Yelagiri Alkaline Complex, South India. Yelagiri syenite is a reversely zoned massif with shoshonitic (Na2O + K2O = 5-10 wt.%, Na2O / K2 O = 0.5-2, TiO2 <0.7 wt.%) And metaluminous character.Systematic modal variation of plagioclase (An11-16Ab82-88), K-feldspar (Or27-95Ab5-61 ), diopside (En34-40Fs11-18Wo46-49), biotite, and Ca-amphibole (edenite) build up three syenite facies within it and imply the role of in situ fractional crystallization (FC). Evidences such as (1) disequilibrium micro-textures in feldspars, (2) microgranular mafic enclaves (MME) and (3) synplutonic dykes signify mixing of shoshonitic mafic magma (MgO = 4-5 wt.%, SiO2 = 54-59 wt.%, K2O / Na2 O = 0.4-0.9) with syenite. Molecular-scale mixing of mafic magma caused disequilibrium growth of feldspars in syenite. Physical entity of mafic magma preserved as MME due to high thermal-rhe ological contrast with syenite magma show various hybridization through chemical exchange, mechanical dilution enhanced by chaotic advection and phenocryst migration. In synplutonic dykes, disaggregation and mixing of mafic magma was confined within the conduit of injection. Major-oxides mass balance test quantified that approximately 0.6 portions of mafic magma had interacted with most evolved syenite magma and generated most hybridized MME and dyke samples. It is unique that all the rock types (syenite, MME and synplutonic dykes) share similar shoshonitic and metaluminous character; mineral chemistry, REE content, coherent geochemical variation in Harker diagram suggest that mixing of magma between similar composition. Outcrop-scale features of crystal accumulation and flow fabrics also significant along with MME and synplutonic dykes in syenite suggesting that Yelagiri syenite magma chamber had evolved through multiple physical processes like convection, shear flow, crystal accumulation and magMummy sex.
其他文献
语文教学的本位就是重积累、重感悟、重读书,我努力把握住这一点,让每一堂语文课都上得有声有色,有情有趣,让学生真正地爱语文,让学生真正地懂语文,让语文课真正成为学生的学习乐园
荆楚文化是中华文化的重要源头,具有鲜明的地域特色,荆楚地区旅游资源丰富、文化底蕴深厚,有巨大的经济文化开发价值.本论文通过对荆楚文化的研究现状、移动端旅游产品的发展
阅读教学从关注阅读量变为关注阅读质量,目前更重视学生的阅读体验。以阅读体验为前提,提高学生阅读时的感受力,进而提高阅读质量,才能保证阅读数量。信息技术作为新时代的教学工
为探究吕家坨井田地质构造格局,根据钻孔勘探资料,采用分形理论和趋势面分析方法,研究了井田7
结合工作经验,针对目前计算机审计中电子数据采集的现状,对计算机审计中电子数据的清理进行了详细的研究,希望能为同行提供参考.
为探究吕家坨井田地质构造格局,根据钻孔勘探资料,采用分形理论和趋势面分析方法,研究了井田7
电力通信网络属于现代智能电网的关键组成部分,具备电力网的功能和通信设施.鉴于环境、设备或人为等方面的因素,可能会导致电力通信网络故障,既会影响电力通信的功能,又可能
New geochemical data of the crater-facies Tokapal kimberlite system sandwiched between the lower and upper stratigraphic horizons of the Mesoproterozoic Indr av
当前,我国电视广播事业发展迅速,DAM全固态中波广播发射机成为了一种应用较为广泛的技术.具有运行成本低、稳定性高等优点,能够在一定程度上为广播事业的发展提供助力.其应用
随着我国科学技术水平的快速发展,我国的互联网技术水平已经上升到了一个新的高度,如今的互联网技术几乎在各个领域都有所应用,而且都取得了非常良好的效果.在社会的一些重要