Determination of the three phase region of the post-spinel transition in (Mg,Fe)2SiO4: explanation of the extreme sharpness of the 660-km discontinuity and implication for chemical structure and dynamics of the deep mantle

(Mg,Fe)2SiO4 后尖晶石相变三相区的确定:解释 660 公里不连续性的极端锐度及其对深部地幔化学结构和动力学的影响

基本信息

项目摘要

Seismic observations indicate that the 660-km discontinuity is less than 2 km thick, corresponding to <0.1 GPa in pressure. Such sharpness is in contrast with that of the 410-km discontinuity, whose thickness is estimated to be 7 km. The 660-km discontinuity is usually explained by the postspinel transition in (Mg,Fe)2SiO4, in which (Mg,Fe)2SiO4 ringwoodite dissociates into (Mg,Fe)SiO3 perovskite plus periclase (Mg,Fe)O. Because these three minerals have Mg-Fe solid solutions, the postspinel transition should have a finite interval, and therefore we need a special explanation to account for the extreme sharpness of the 660-km discontinuity. For this reason, the transition interval of the postspinel transition must be determined. If the pressure interval of the transition is >0.1 GPa, we will have to reconsider the structure and dynamics of the deep mantle. Firstly, it is possible that the chemical compositions are different between the upper and lower mantles, and that mantle convection is at least partially layered. An alternative explanation is that the sluggish kinetics of nucleation prevents initiation of the postspinel transition, and once nucleation occurs, the transition proceeds very rapidly. If it is proved that the interval of the postspinel transition is extremely thin, the presence of vertical mantle flow could be assessed by global variation of the thickness of the 660-km discontinuity. Previous experimental studies have not successfully determined the pressure interval of the postspinel transition because they have lacked sufficient precision in pressure determination and suffered from the effects of sluggish kinetics. The precision of pressure determination in previous studies was no better than 0.3 GPa, which was too large to determine the transition interval, which could be less than 0.1 GPa. In contrast, the applicant has already established experimental techniques to determine sample pressure with a precision of 0.04 GPa, which should be sufficient for the present project. He has also established an experimental technique to obtain the equilibrium compositions of minerals by using a flux. Combining these two techniques, the whole three phase region of ringwoodite+perovskite+periclase will be determined in pressure-composition space at a constant temperature of 2000 K. The pressure interval of the postspinel transition in the real mantle will be estimated based on the geometry of the three phase region by considering the expected Mg-Fe exchange with majorite.
地震观测表明,660公里长的不连续面厚度不到2公里,对应的压力小于0.1 GPa。这种尖锐程度与410公里的不连续性形成对比,后者的厚度估计为7公里。660 km的不连续性通常被解释为(Mg,Fe)2SiO 4的后尖晶石转变,其中(Mg,Fe)2SiO 4环伍德石分解为(Mg,Fe)SiO 3钙钛矿和方镁石(Mg,Fe)O。由于这三种矿物都有Mg-Fe固溶体,所以后尖晶石转变应该有一个有限的时间间隔,因此我们需要一个特殊的解释来解释660 km不连续面的极端尖锐性。因此,必须确定后尖晶石转变的转变间隔。如果转换的压力间隔大于0.1GPa,我们将不得不重新考虑深部地幔的结构和动力学。首先,可能上地幔和下地幔的化学成分不同,地幔对流至少部分是分层的。另一种解释是缓慢的成核动力学阻止了后尖晶石转变的开始,并且一旦成核发生,转变进行得非常迅速。如果证明后尖晶石过渡的间隔非常薄,则可以通过660 km不连续面厚度的全球变化来评估垂直地幔流的存在。以前的实验研究没有成功地确定的压力区间的postpinite转变,因为他们缺乏足够的精度,在压力测定和遭受的影响,缓慢的动力学。以往研究中压力测定的精度不优于0.3 GPa,这太大,无法确定过渡间隔,过渡间隔可以小于0.1 GPa。相比之下,申请人已经建立了实验技术,以0.04 GPa的精度确定样品压力,这对于本项目来说应该足够了。他还建立了一种实验技术,通过使用助熔剂获得矿物的平衡组成。结合这两种技术,在2000 K恒温条件下,在压力-成分空间中确定了林伍德石+钙钛矿+方镁石的整个三相区。根据三相区的几何形状,考虑到镁铁交换,估算了真实的地幔中后尖晶石转变的压力区间。

项目成果

期刊论文数量(0)
专著数量(0)
科研奖励数量(0)
会议论文数量(0)
专利数量(0)

数据更新时间:{{ journalArticles.updateTime }}

{{ item.title }}
{{ item.translation_title }}
  • DOI:
    {{ item.doi }}
  • 发表时间:
    {{ item.publish_year }}
  • 期刊:
  • 影响因子:
    {{ item.factor }}
  • 作者:
    {{ item.authors }}
  • 通讯作者:
    {{ item.author }}

数据更新时间:{{ journalArticles.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ monograph.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ sciAawards.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ conferencePapers.updateTime }}

{{ item.title }}
  • 作者:
    {{ item.author }}

数据更新时间:{{ patent.updateTime }}

Professor Dr. Tomoo Katsura其他文献

Professor Dr. Tomoo Katsura的其他文献

{{ item.title }}
{{ item.translation_title }}
  • DOI:
    {{ item.doi }}
  • 发表时间:
    {{ item.publish_year }}
  • 期刊:
  • 影响因子:
    {{ item.factor }}
  • 作者:
    {{ item.authors }}
  • 通讯作者:
    {{ item.author }}

{{ truncateString('Professor Dr. Tomoo Katsura', 18)}}的其他基金

Evaluation of the aspect ratio of ferropericlase under lower-mantle conditions
下地幔条件下方镁石长径比的评估
  • 批准号:
    449701262
  • 财政年份:
    2020
  • 资助金额:
    --
  • 项目类别:
    Research Grants
Determination of water partition coefficients between upper mantle minerals and melts as a function of pressure, temperature, and CO2 content using a rapid quench cell in multi-anvil experiments
在多砧实验中使用快速淬火室确定上地幔矿物和熔体之间的水分配系数作为压力、温度和 CO2 含量的函数
  • 批准号:
    402695659
  • 财政年份:
    2018
  • 资助金额:
    --
  • 项目类别:
    Research Grants
Determining the water dissociation constant from the relationship between water solubility in ringwoodite and oxygen fugacity
根据尖晶橄榄石的水溶性与氧逸度之间的关系确定水解离常数
  • 批准号:
    392411544
  • 财政年份:
    2018
  • 资助金额:
    --
  • 项目类别:
    Research Grants
Measurement of Si grain-boundary diffusion coefficients of forsterite as a function of water content: Estimation of the degree of creep enhancement with water within different regions of the upper mantle
镁橄榄石硅晶界扩散系数随含水量变化的测量:估计上地幔不同区域内水的蠕变增强程度
  • 批准号:
    247132310
  • 财政年份:
    2014
  • 资助金额:
    --
  • 项目类别:
    Research Grants
Measurement of Si self-diffusion coefficients of wadsleyite as a function of water content
硅锰矿硅自扩散系数随含水量变化的测量
  • 批准号:
    251472533
  • 财政年份:
    2014
  • 资助金额:
    --
  • 项目类别:
    Research Grants
Dislocation recovery experiment of hydrous olivine as a function of water content and crystallographic orientation
水合橄榄石的位错恢复实验作为含水量和晶体取向的函数
  • 批准号:
    229061489
  • 财政年份:
    2012
  • 资助金额:
    --
  • 项目类别:
    Research Grants
Accurate determination of the melting relations of primitive peridotite under lower-mantle conditions up to 35 GPa using advanced multi-anvil techniques
利用先进的多砧技术准确测定高达 35 GPa 的下地幔条件下原始橄榄岩的熔化关系
  • 批准号:
    461495683
  • 财政年份:
  • 资助金额:
    --
  • 项目类别:
    Research Grants
H2O solubilities in Al-free and Al-bearing high-pressure silica polymorphs as a function of pressure and temperature: H2O storage in the lower mantle
无铝和含铝高压二氧化硅多晶型物中的水溶解度与压力和温度的函数关系:下地幔中的水储存
  • 批准号:
    518398967
  • 财政年份:
  • 资助金额:
    --
  • 项目类别:
    Research Grants

相似国自然基金

隧道超前探测的三分量光纤地震加速度检波机理与应用研究
  • 批准号:
    51079080
  • 批准年份:
    2010
  • 资助金额:
    32.0 万元
  • 项目类别:
    面上项目
肝脏管道系统数字化及三维成像的研究
  • 批准号:
    30470493
  • 批准年份:
    2004
  • 资助金额:
    23.0 万元
  • 项目类别:
    面上项目

相似海外基金

Protein structure determination from low-resolution experimental data
从低分辨率实验数据确定蛋白质结构
  • 批准号:
    10224234
  • 财政年份:
    2017
  • 资助金额:
    --
  • 项目类别:
Protein structure determination from low-resolution experimental data
从低分辨率实验数据确定蛋白质结构
  • 批准号:
    9768492
  • 财政年份:
    2017
  • 资助金额:
    --
  • 项目类别:
Protein structure determination from low-resolution experimental data
从低分辨率实验数据确定蛋白质结构
  • 批准号:
    9287589
  • 财政年份:
    2017
  • 资助金额:
    --
  • 项目类别:
Integrated tools for higher order structure determination by cross-link analysis
通过交联分析确定高阶结构的集成工具
  • 批准号:
    9347159
  • 财政年份:
    2017
  • 资助金额:
    --
  • 项目类别:
An Automated RNA 3D Structure Determination System
自动化 RNA 3D 结构测定系统
  • 批准号:
    8931349
  • 财政年份:
    2014
  • 资助金额:
    --
  • 项目类别:
A new approach to solvent determination in QM/MM-based X-ray crystallographic refinement
基于 QM/MM 的 X 射线晶体学精修中溶剂测定的新方法
  • 批准号:
    8834159
  • 财政年份:
    2014
  • 资助金额:
    --
  • 项目类别:
HT structure determination of GPCRs by LCP serial femtosecond nanocrystallography
LCP 系列飞秒纳米晶体学测定 GPCR 的 HT 结构
  • 批准号:
    8612932
  • 财政年份:
    2014
  • 资助金额:
    --
  • 项目类别:
An Automated RNA 3D Structure Determination System
自动化 RNA 3D 结构测定系统
  • 批准号:
    8713143
  • 财政年份:
    2014
  • 资助金额:
    --
  • 项目类别:
Rapid ultra-sensitive three dimensional protein structure determination by mass s
通过质量数快速测定超灵敏三维蛋白质结构
  • 批准号:
    8319335
  • 财政年份:
    2011
  • 资助金额:
    --
  • 项目类别:
Rapid ultra-sensitive three dimensional protein structure determination by mass s
通过质量数快速测定超灵敏三维蛋白质结构
  • 批准号:
    8164717
  • 财政年份:
    2011
  • 资助金额:
    --
  • 项目类别:
{{ showInfoDetail.title }}

作者:{{ showInfoDetail.author }}

知道了