相关实验视频
Updated: Jul 12, 2026

08:14
Atom Probe Tomography Analysis of Exsolved Mineral Phases
Published on: October 25, 2019
下层地的侧面同位素不连续性:来自南极洲的一个例子
概括
研究南极的下层地颗粒物揭示了重要的组成和年龄不连续性. 这一通过和氧同位素识别的地质边界,可能表明跨南极山脉下面有一个古老的.
科学领域:
- 地质化学 地质化学
- 石化学 石化学是一门学科.
- 构造学 构造学 构造学 构造学
背景情况:
- 下大陆地的组成和演变仍然不太清楚.
- 了解地的异质性是破译地球地-地幔动态的关键.
研究的目的:
- 研究南极洲麦克默多湾地区下大陆地的性质和组成异质性.
- 为了分析和氧同位素,主要和微量元素的下层地颗粒物入.
主要方法:
- 分析了来自南极洲火山岩的20多个颗粒岩.
- 斯特和氧同位素的地球化学.
- 主要和微量元素分析.
主要成果:
- 确定了下层地组成和年龄的明显不连续性.
- 这种不连续性与跨南极山脉和罗斯湾之间的边界一致.
- 同位素的差异表明,这个边界可能代表着古代地的接.
结论:
- 麦克默多湾地区的下层地表现出显著的异质性.
- 观察到的边界可能意味着一个长期存在的构造特征,可能是一个古老的线区域.
- 当前的代裂变可能正在重新激活这个古老的地边界.
相关概念视频
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...
Isothermal Processes
A thermodynamic process that occurs at constant temperature is called an isothermal process. Heat slowly flows into the system or out of the system to maintain thermal equilibrium. Processes involving phase changes like water evaporation into steam or freezing water into ice at a constant temperature are examples of Isothermal Processes.
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
An ideal gas can also undergo isothermal expansion or compression.
For example, consider 1 mole of an ideal gas inside an isolated cylinder at initial volume V...
Inductively Coupled Plasma-Mass Spectrometry (ICP-MS): Interferences
Inductively coupled plasma–mass spectrometry (ICP–MS) is a highly selective and sensitive technique for accurate elemental analysis. Though the analysis of ICP–MS mass spectra is comparatively straightforward, it is affected by spectroscopic and non-spectroscopic interferences. Spectroscopic interferences arise when the plasma contains ionic species with an m/z value the same as the analyte ion. Spectroscopic interference can be categorized as isobaric, polyatomic ions, and refractory oxide ion...
Imperfections in Crystal Structure: Point, Line and Plane Defects
A perfect crystal, in theory, has a uniform structure with the same unit cell and lattice points throughout. However, any deviation from this periodic arrangement is known as an imperfection or defect. These defects can be categorized into three types: point, line, and plane defects.Point defects occur when there is a deviation from the ideal due to missing atoms, displaced atoms, or additional atoms. These imperfections might occur due to imperfect packing during crystallization or because of...
Phase Transitions: Melting and Freezing
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
Atomic Nuclei: Nuclear Spin State Population Distribution
Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy spin-down state. As temperatures increase, the energy from thermal collisions distributes the spins more equally between the two states. The Boltzmann distribution equation gives the ratio of the number of spins predicted in the spin −½ (N−) and spin +½ (N+) states.

