大陆物质可能潜入超过200公里的深度
1Laboratory of Lithosphere Tectonic Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing. yekai@hotmail.com
Nature
|October 26, 2000
概括
大陆物质可以在200公里深处被沉积,这是石榴石中溶解的证据. 这一发现有助于理解超大陆增长和板块边缘动态.
科学领域:
- 地质地质地质地质地质地
- 地质物理学 地质物理学
- 矿物学是一门学科.
背景情况:
- 大陆石化层的沉降是超大陆周期和板块边缘演变的关键.
- 超高压 (UHP) 变态岩石表明大陆物质可以达到至少120公里的深度.
- 之前对更深的沉积 (150-300公里) 的推断依赖于石榴石石的间接证据.
研究的目的:
- 直接追踪UHP变态地岩中的大陆沉降深度.
- 为了确定深度大陆沉积的可靠矿物学指标.
- 为了测试深度在150公里以上的石榴石中氧溶解的预测.
主要方法:
- 来自苏鲁UHP变态带的生态石的分析,中国.
- 在石榴石中的矿物溶液的微观和化学分析.
- 解释矿物化学 (Na2O,八面体Si) 以推断压力深度条件.
主要成果:
- 观察到高度的clinopyroxene,rutile和apatite在石榴石中的溶解.
- 解释这些溶解为高压氧化物固体溶液形成的证据.
- 确定观察到的Na2O和八面体Si度表明潜水深度超过200公里.
结论:
- 大陆物质可以被沉积到200公里以上的深度.
- 石榴石中的溶解纹理提供了深度大陆沉降的直接指标.
- 这为了解在收边缘的深层地过程提供了关键数据.
相关概念视频
Phase Transitions: Sublimation and Deposition
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
Additional Subnuclear Structures
The eukaryotic nucleus is a double membrane-bound organelle that contains nearly all of the cell’s genetic material in the form of chromosomes. It is rightly called the “brain” of the cell as it shoulders the responsibility of responding to various physiological processes, stress, altered metabolic conditions, and other cellular signals.
The nucleus contains many membrane-less subnuclear organelles or nuclear bodies, such as nucleoli, Cajal bodies, speckles, paraspeckles, etc. These nuclear...
The nucleus contains many membrane-less subnuclear organelles or nuclear bodies, such as nucleoli, Cajal bodies, speckles, paraspeckles, etc. These nuclear...
Additional Subnuclear Structures
The eukaryotic nucleus is a double membrane-bound organelle that contains nearly all of the cell’s genetic material in the form of chromosomes. It is rightly called the “brain” of the cell as it shoulders the responsibility of responding to various physiological processes, stress, altered metabolic conditions, and other cellular signals.
The nucleus contains many membrane-less subnuclear organelles or nuclear bodies, such as nucleoli, Cajal bodies, speckles, paraspeckles, etc. These nuclear...
The nucleus contains many membrane-less subnuclear organelles or nuclear bodies, such as nucleoli, Cajal bodies, speckles, paraspeckles, etc. These nuclear...
Magnetostatic Boundary Conditions
An electric field suffers a discontinuity at a surface charge. Similarly, a magnetic field is discontinuous at a surface current. The perpendicular component of a magnetic field is continuous across the interface of two magnetic mediums. In contrast, its parallel component, perpendicular to the current, is discontinuous by the amount equal to the product of the vacuum permeability and the surface current. Like the scalar potential in electrostatics, the vector potential is also continuous...
Gravimetry: Overview
Gravimetric analysis is a quantitative method where the analyte is isolated and weighed directly or after conversion into a substance of known composition. Gravimetric analysis can be classified as precipitation, electrogravimetry, volatilization, and particulate gravimetry, based on the method used to isolate the analyte.
In precipitation gravimetry, the analyte is converted into a precipitate and weighed. For example, the silver content in a sample can be estimated by precipitating and...
In precipitation gravimetry, the analyte is converted into a precipitate and weighed. For example, the silver content in a sample can be estimated by precipitating and...
Deep Sea Microbial Ecology
The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...


