压力诱导的形态变化引发了岩层地幔的变形
Vahid Samae1, Patrick Cordier2,3, Sylvie Demouchy4
1Electron Microscopy for Materials Science, University of Antwerp, Antwerp, Belgium.
Nature
|March 4, 2021
概括
富含橄素的岩石在压力下通过粒边形变形,使其具有可塑性. 这种机制解释了地球上的塑料流动.
科学领域:
- 地质学
- 材料科学
- 矿物物理
背景情况:
- 富含橄素的岩石的机械性质对于理解石化层与石化层的合至关重要.
- 晶体缺陷运动控制了晶体材料中的塑料流动,但由于有限的滑动系统,橄需要额外的变形机制.
- 谷物边界滑动是橄变形的一个建议机制,但其微观结构基础和理论整合仍然不清楚.
研究的目的:
- 识别和描述橄丰富的岩石中的粒度边界的变形机制.
- 为将粒度边界力学纳入多晶可塑性模型提供理论框架.
- 解释富含橄素的材料中的可塑性和塑料流动.
主要方法:
- 在压力下对石 (一种富含橄素的矿物质) 的实验研究.
- 微观结构分析侧重于谷物边界.
- 多晶性可塑性的理论建模.
主要成果:
- 在压力下,石的粒度边界发生无形化.
- 在谷物边界的无形层的发展激活了谷物边界的移动性,导致了可塑性.
- 这种机制特别适用于石化层与石化层的界限,在那里,橄石接近其玻璃过渡温度.
结论:
- 一种新的压力诱导的无形化机制控制了富含橄素的岩石的可塑性.
- 这一过程促进了深层地球环境中的塑料流动,特别是在易碎塑料过渡和石化层-石化层边界.
- 这些发现为了解大规模地质变形提供了新的理论基础.
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