由 akimotoite-bridgmanite过渡引起的压缩660公里的不连续性
Artem Chanyshev1,2, Takayuki Ishii3,4, Dmitry Bondar5
1Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany. artem.chanyshev@uni-bayreuth.de.
Nature
|January 6, 2022
概括
660公里的地震断裂
科学领域:
- 地质学
- 矿物物理
- 高压地质化学
背景情况:
- 660公里的地震断层标志着地球的下层地幔与过渡区之间的边界.
- 它通常归因于环木石的脊柱后转变为桥石和铁烯酸.
- 这种不连续性在俯冲区下显著下降,目前的模型无法完全解释这一现象.
研究的目的:
- 准确确定后脊柱和 akimotoite-bridgmanite过渡的阶段边界.
- 调查这些过渡的温度依赖性和克拉佩隆斜率.
- 为了重新解释660公里不连续性的原因.
主要方法:
- 使用多个杆实验进行高压合成.
- 在现场使用X射线衍射以准确识别相位和确定边界.
- 专注于严格遵守相位平衡定义的实验.
主要成果:
- 脊柱后的过渡边界表现出最小的温度依赖.
- 在环境地幔地热以下的温度下, akimotoite-bridgmanite过渡显示了的负边界斜率.
- 这些发现挑战了以前对660公里的不连续性深度的解释.
结论:
- 在寒冷的潜伏区下面660公里的不连续性被归因于 akimotoite-bridgmanite过渡.
- 这种转变的急剧负倾斜表明了显著的上升性,导致板块停滞.
- 这项研究完善了我们对地幔动力学和俯冲过程的理解.
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