Complete agreement of the post-spinel transition with the 660-km seismic discontinuity.
Complete agreement of the post-spinel transition with the 660-km seismic discontinuity.
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DOI：
10.1038/s41598-018-24832-y
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发表时间：
2018-04-20
影响因子：
4.6
通讯作者：
Katsura T
中科院分区：
文献类型：
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作者：
Ishii T;Huang R;Fei H;Koemets I;Liu Z;Maeda F;Yuan L;Wang L;Druzhbin D;Yamamoto T;Bhat S;Farla R;Kawazoe T;Tsujino N;Kulik E;Higo Y;Tange Y;Katsura T
660公里的地震不连续面，这是一个重要的结构，在地球的地幔，通常被解释为后尖晶石过渡，如所示的分解ringwoodite的bridgmanite +铁方镁石。然而，所有精确的高压和高温实验报告的转变压力比在不连续深度（即23.4 GPa）预期的低0.5-2 GPa。这些结果与后尖晶石过渡假说不一致，因此，不支持广泛接受的地幔组成模型，如软锰矿和CI球粒陨石模型。在这里，我们提出了新的实验数据，显示后尖晶石过渡压力与660公里的不连续深度完全一致，通过高分辨率原位X射线衍射在一个大容量的高压装置与严格控制的样品压力。这些数据证实了流行的地幔模型的适用性。我们推断，以前的研究报告的明显较低的压力是由于加热时的压降实验文物。目前的研究结果表明，有必要重新调查的地幔矿物相边界的位置以前获得的高压-温度装置中的现场X射线衍射。
The 660-km seismic discontinuity, which is a significant structure in the Earth’s mantle, is generally interpreted as the post-spinel transition, as indicated by the decomposition of ringwoodite to bridgmanite + ferropericlase. All precise high-pressure and high-temperature experiments nevertheless report 0.5–2 GPa lower transition pressures than those expected at the discontinuity depth (i.e. 23.4 GPa). These results are inconsistent with the post-spinel transition hypothesis and, therefore, do not support widely accepted models of mantle composition such as the pyrolite and CI chondrite models. Here, we present new experimental data showing post-spinel transition pressures in complete agreement with the 660-km discontinuity depth obtained by high-resolution in situ X-ray diffraction in a large-volume high-pressure apparatus with a tightly controlled sample pressure. These data affirm the applicability of the prevailing mantle models. We infer that the apparently lower pressures reported by previous studies are experimental artefacts due to the pressure drop upon heating. The present results indicate the necessity of reinvestigating the position of mantle mineral phase boundaries previously obtained by in situ X-ray diffraction in high-pressure–temperature apparatuses.
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影响因子：
5.3
作者：
Houser, C.
通讯作者：
Houser, C.
影响因子：
2.8
作者：
Houser, C.;Masters, G.;Shearer, P.
通讯作者：
Shearer, P.
影响因子：
2.3
作者：
Nishiyama, N;Irifune, T;Funakoshi, K
通讯作者：
Funakoshi, K
影响因子：
3.9
作者：
Speziale, S;Zha, CS;Mao, HK
通讯作者：
Mao, HK
DOI：
10.1029/jb094ib11p15671
发表时间：
1989-11-10
期刊：
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH AND PLANETS
影响因子：
--
作者：
AKAOGI, M;ITO, E;NAVROTSKY, A
通讯作者：
NAVROTSKY, A