哥伦比亚河洪水玄武岩和沃洛瓦山脉在俄勒冈州东北部升起的石质层不稳定的起源
T C Hales1, D L Abt, E D Humphreys
1Department of Geological Sciences, 1272 University of Oregon, Eugene, Oregon 97403, USA. thales@uoregon.edu
Nature
|December 13, 2005
概括
哥伦比亚河基岩 (CRB) 起源于沃洛瓦山脉附近,而不是黄石热点轨道. 地幔下垂和脱离的浮动根解释了CRB的岩和升起.
科学领域:
- 地质物理学 地质物理学
- 火山学 火山学是一门学科.
- 地质化学 地质化学
背景情况:
- 洪水玄武岩与热点启动有关.
- 哥伦比亚河基岩 (CRB) 是与黄石热点相关的最大的洪水基岩.
- CRB源在沃洛瓦山脉附近,距离预计的热点轨道以北500公里.
研究的目的:
- 调查哥伦比亚河岩 (CRB) 的来源和升起机制.
- 确定瓦洛瓦山区下面的地幔结构.
- 与CRB的位置和表面变形相关联地幔特性.
主要方法:
- 对地幔的地震速度结构分析.
- 创建岩流的侵蚀纠正的海拔地图.
- 沃洛瓦山脉地区的地质地图.
主要成果:
- 在沃洛瓦山脉下方确定了一个地幔融含量减少的区域.
- 观察到一个200公里宽的地形上升,以沃洛瓦山脉为中心.
- 记录了瓦洛瓦山脉的爆发前沉降,随后是协同爆发和长期升起.
结论:
- 电流下流和密集的浮动根的脱离解释了CRB的磁性.
- 这种机制解释了观测到的表面升起和融化耗尽的地幔.
- 沃洛瓦山脉地区是了解洪水玄武岩起源的关键区域.
更多相关视频
06:55Kinematic History of a Salient-recess Junction Explored through a Combined Approach of Field Data and Analog Sandbox Modeling
Published on: August 5, 2016
07:58Data Processing Methods for 3D Seismic Imaging of Subsurface Volcanoes: Applications to the Tarim Flood Basalt
Published on: August 7, 2017
相关概念视频
Rab Cascades
Rab GTPases act in a regulated cascade during membrane fusion, helping the lipid bilayers mix. The Rab family of proteins are active when bound to GTP, and inactive when bound to GDP. Hence, they act as guanine nucleotide-dependent molecular switches. Rab-GTP recognizes and binds to long or short-range tethering proteins to capture the target vesicle. These tethers coordinate with SNAREs on the vesicle and the target membrane to assemble the trans SNARE complex that locks the mixing bilayers.
Fault Types
When analyzing a single line-to-ground fault from phase A to ground at a three-phase bus, it is important to consider the fault impedance. This impedance is zero for a bolted fault, equal to the arc impedance for an arcing fault, and represents the total fault impedance for a transmission-line insulator flashover. To derive sequence and phase currents, fault conditions are translated from the phase domain to the sequence domain.
For line-to-line faults occurring between phases B and C, the...
For line-to-line faults occurring between phases B and C, the...
Expansion and Contraction in Masonry Walls
Masonry walls are subject to slight expansion and contraction due to variations in temperature and moisture. Thermal movement in masonry is relatively straightforward to measure and plan for. On the other hand, moisture movement poses more of a challenge. New clay masonry units typically absorb water and expand over time under normal environmental conditions. Conversely, new concrete masonry units tend to shrink as they lose the excess moisture acquired during their production process.
To...
To...
Lumber Defects
Lumber defects, which can affect both the appearance and structural integrity of wood, include a variety of growth and manufacturing flaws. Growth defects such as knots and knotholes occur where branches were once attached to the tree trunk, with knotholes forming when these knots fall out. Other natural defects include decay and insect damage, which compromise the wood's strength and durability.
Shakes are minor fractures that run along or across the wood's annual rings, while wane is...
Shakes are minor fractures that run along or across the wood's annual rings, while wane is...
Portland Cement
Portland cement is the essential binding ingredient in concrete, made from finely ground materials including lime, iron, silica, and alumina. Lime is derived primarily from limestone, marble, marl, seashells, and clays, which also supply iron and alumina, while silica is sourced from sand, chalk, and bauxite. Contemporary manufacturing of Portland cement is a significant source of carbon dioxide emissions, prompting research into reducing its content in concrete through alternative...
Origin of Photosynthesis
Photosynthesis represents a fundamental biological process that transformed Earth's atmosphere and paved the way for complex life. Emerging roughly 3.4–3.8 billion years ago, the earliest photosynthetic organisms harnessed light energy to produce organic compounds. These anoxygenic phototrophs used electron donors like hydrogen sulfide (H₂S) or ferrous iron (Fe²⁺), rather than water, and did not release molecular oxygen (O₂) as a byproduct. Various groups, including green sulfur and purple...
