奥利文的条纹铁区划是由位爬行诱导的,在变形的周周中
1Department of Earth and Planetary Systems Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan. ando@letitbe.geol.sci.hiroshima-u.ac.jp
Nature
|January 10, 2002
概括
研究人员在地球地幔中常见的矿物质橄中发现了条纹铁区分. 这种由位移爬行驱动的化学区分,发生在亚粒边界,可能会影响深度焦点地震.
科学领域:
- 地质化学 地质化学
- 矿物物理 矿物物理
- 固态化学 固态化学
背景情况:
- 固体中的变形过程改变了微观结构和微化学.
- 在扩散爬行过程中记录了化学分离,但从位移爬行中划分区域仍然没有观察到.
- 橄 ((Mg,Fe) 2SiO4) 是地球上层地幔的一个关键矿物.
研究的目的:
- 为了研究由位爬行变形引起的橄石中的化学区分.
- 要了解铁区划背后的机制,在变形的周周石.
- 探索这种区域划分对地幔过程和地震性的影响.
主要方法:
- 分析因位爬行而变形的自然矿样本.
- 微化学分析以确定铁度模式.
- 实验室实验在不同的应变速率观察区分形成.
主要成果:
- 关于从变形的周周岩石中在橄石中划分条纹铁的第一份报告.
- 铁度在亚粒边界上升,与边缘位移有关.
- 在高应变率实验中,区域划分是缺席的,在这些实验中,位移移动太快,无法形成科特雷尔大气层.
结论:
- 由于脱位爬行造成的变形,可以在最初同质的固体中引发化学区分,例如橄.
- 形成机制涉及边缘位移,将铁原子的科特雷尔大气层拖入亚粒边界.
- 这种铁的区分可能会通过影响地幔的相位转换来发挥深度焦点地震发生的作用.
相关概念视频
Actin Treadmilling
7.9K
Actin filaments undergo polymerization and depolymerization from either end. The polymerization and depolymerization rates depend on the cytosolic concentration of free G-actins. The polymerization rate is generally higher at the plus or barbed end, while the depolymerization rate is higher at the minus or pointed end. At a steady state, critical concentration describes the concentration of free G-actin monomers at which the polymerization rate at the plus end is equal to that of the...
7.9K
Area Computation by the Alternative Coordinate Method
860
The alternative coordinate method, also known as the Shoelace Formula, is a technique for determining the area of a traverse using Cartesian coordinates. This method relies on the sequential arrangement of x and y coordinates for each point of the shape, ensuring accuracy and ease of application.In this approach, each corner's x and y coordinates are listed as fractions, with the x-coordinate as the numerator and the y-coordinate as the denominator. These coordinates are arranged sequentially...
860
Piecewise-Defined Functions
509
Piecewise defined functions are mathematical models where different expressions define a function over distinct intervals of the domain. These functions are useful for representing systems with varying behaviors depending on input values.For example, the function: uses a linear rule for inputs less than or equal to –1 and a quadratic rule for values greater than –1. Although it has two formulas, it still defines a single function.Another common type is the absolute value...
509
Transformations of Functions I
286
A function's graph can be modified by changing its position or size without altering its overall shape. These transformations allow the graph to be moved across the coordinate plane while preserving its pattern and structure. One of the most common transformations is shifting, which repositions the graph without distorting it.When the output of a function is adjusted by adding or subtracting a constant, the graph shifts vertically. A positive value moves the graph upward, while a negative value...
286
Orthogonal Trajectories
303
Orthogonal trajectories describe the geometric relationship between two families of curves that intersect each other at right angles. One illustrative case involves a family of parabolas that open sideways along the x-axis. These curves share a common shape but differ by a scaling parameter, resulting in a set of curves that all pass through the origin and widen at different rates.Determining Orthogonal TrajectoriesTo identify the orthogonal trajectories for these parabolas, the first step...
303
Transformations of Functions III
304
Transformations modify the graphical representation of a function without changing its fundamental form. One common transformation is reflection, which flips the graph across a designated axis. When the vertical coordinates of all points are multiplied by the negative one, the entire graph is mirrored over the horizontal axis. This transformation reverses the vertical orientation of peaks and troughs, akin to signal inversion in electrical systems, where a waveform is flipped, but the timing of...
304


