在东太平洋上升的重叠扩散中心下方连续地幔融供应
R A Dunn1, D R Toomey, R S Detrick
1Department of Geological Sciences, University of Oregon, Eugene, OR 97403-1272, USA. Robert_Allen_Dunn@brown.edu
概括
东太平洋上升的重叠扩散中心显示连续的低P波速度,表明来自单个地幔源的稳定融供应. 构造学细分并不是深度岩细分的直接结果.
科学领域:
- 地质物理学 地质物理学
- 地震学 地震学
- 地幔动力学地幔动力学
背景情况:
- 叠加的扩散中心 (OSC) 是中洋山脊的特征.
- 了解OSC下面的融化供应对于板块构造学至关重要.
- 之前的模型表明,OSCs的融供应中存在不连续性.
研究的目的:
- 为了研究一个OSC下方的上层地幔速度结构.
- 为了确定融化供应给OSCs的性质.
- 评估构造学和岩石细分之间的关系.
主要方法:
- 使用P波速度的地震断层扫描.
- 对上层地幔结构的断层图像进行分析.
- 温度和融化分量的建模.
主要成果:
- 在OSC下方确定了低P波速度的连续区域.
- 解释这是一个高温区域,几百分比化.
- 证明OSC的两个肢体都由一个单一的底层地幔源来供应.
结论:
- OSCs并不一定与不连续的融供应有关.
- 融化供应是连续从一个更深的地幔源.
- 通过OSCs对山脊的构造学细分与深度的岩细分脱.
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