Crystal fractionation of granitic magma during its non-transport processes: A physics-based perspective
文献类型：CNKI期刊论文
| 作者 | CHEN Chen ; DING Xing; LI Rui; ZHANG WeiQi; OUYANG DongJian; YANG Lei; SUN WeiDong
|
| 发表日期 | 2018-02-01 |
| 出处 | Science China(Earth Sciences)
 |
| 关键词 | Granite Crystal fractionation Magma convection Layering structure Mush model Highly fractionated granite Granite complex Li-F granite |
| 英文摘要 | Granitic continental crust distinguishes the Earth from other planets in the Solar System. Consequently, for understanding terrestrial continent development, it is of great significance to investigate the formation and evolution of granite.Crystal fractionation is one of principal magma evolution mechanisms. Nevertheless, it is controversial whether crystal fractionation can effectively proceed in felsic magma systems because of the high viscosity and non-Newtonian behavior associated with granitic magmas. In this paper, we focus on the physical processes and evaluate the role of crystal fractionation in the evolution of granitic magmas during non-transport processes, i.e., in magma chambers and after emplacement. Based on physical calculations and analyses, we suggest that general mineral particles can settle only at tiny speed(~10~(-9)–10~(-7) m s~(-1))in a granitic magma body due to high viscosity of the magma; however, the cumulating can be interrupted with convection in magma chambers, and the components of magma chambers will tend to be homogeneous. Magma convection ceases once the magma chamber develops into a mush(crystallinity, F>~40–50%). The interstitial melts can be extracted by hindered settling and compaction, accumulating gradually and forming a highly silicic melt layer. The high silica melts can further evolve into high-silica granite or high-silica rhyolite. At various crystallinities, multiple rejuvenation of the mush and the following magma intrusion may generate a granite complex with various components. While one special type of granites, represented by the South China lithium-and fluoride-rich granite, has lower viscosity and solidus relative to general granitic magmas, and may form vertical zonation in mineral-assemblage and composition through crystal fractionation. Similar fabrics in general intrusions that show various components on small lengthscales are not the result of gravitational settling. Rather, the flowage differentiation may play a key role. In general, granitic magma can undergo effective crystal fractionation; high-silica granite and volcanics with highly fractionated characteristics may be the products of crystal fractionation of felsic magmas, and many granitoids may be cumulates. |
| 文献子类 | CNKI期刊论文 |
| 资助机构 | supported by the National Key R&D Program of China (Grant Nos. 2016YFC0600204 & 2016YFC0600408) ; the National Natural Science Foundation of China (Grant Nos. 41421062 & 41372005) |
| 卷 | v.61期:02页:72-86 |
| 语种 | 英文; |
| 分类号 | P588.121 |
| ISSN号 | 1674-7313 |
| 源URL | [http://ir.qdio.ac.cn/handle/337002/189025]  |
| 专题 | 中国科学院海洋研究所 |
| 作者单位 | 1.CASKeyLaboratoryofMineralogyandMetallogeny,GuangzhouInstituteofGeochemistry,ChineseAcademyofSciences 2.UniversityofChineseAcademyofSciences 3.StateKeyLaboratoryofIsotopeGeochemistry,GuangzhouInstituteofGeochemistry,ChineseAcademyofSciences 4.CASCenterforExcellenceinTibetanPlateauEarthSciences,ChineseAcademyofSciences 5.StateKeyLaboratoryofLithosphericEvolution,InstituteofGeologyandGeophysics,ChineseAcademyofSciences 6.CenterofDeepSeaResearch,InstituteofOceanography,ChineseAcademyofSciences 7.LaboratoryforMarineMineralResources,QingdaoNationalLaboratoryforMarineScienceandTechnology |
| 推荐引用方式 GB/T 7714 | CHEN Chen,DING Xing,LI Rui,et al. Crystal fractionation of granitic magma during its non-transport processes: A physics-based perspective. 2018. |
入库方式： OAI收割
来源：海洋研究所
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