Melt Extraction and Crustal Accretion at Mid-Ocean Ridges: Continued Study of the Mantle and Lower Crust in the Oman Ophiolite

大洋中脊的熔体萃取和地壳增生：阿曼蛇绿岩中地幔和下地壳的继续研究

• 批准号: 9819666
• 负责人: Peter Kelemen
• 金额: $ 35万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2003-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9819666&HistoricalAwards=false
• 关键词: Melt; Extraction; Crustal; Accretion; Mid

This grant will fund a 3 year study of the genesis of the oceanic crust at spreading ridges, based on evidence from the mantle and lower crust of a thrust slice of oceanic crust and upper mantle in Oman. Our main objectives are to constrain (1) porous flow and/or fracture mechanisms of melt extraction from the mantle, and (2) formation of the igneous lower oceanic crust via combinations of two end-member possibilities: (a) crystallization in a single magma chamber plus ductile flow downward and outward to form the lower crust, and (b) crystallization of lower crustal plutonic rocks in many small magma chambers close to their current depth of emplacement. In addition, we seek to address related questions concerning (3) melt extraction mechanisms in the lower crust, (4) deformation mechanisms and strain partitioning in the lower crust, and (5) igneous cooling and crystallization rates beneath the axis of an oceanic spreading ridge.

这笔赠款将资助一项为期3年的研究，根据阿曼洋壳和上地幔冲断层的地幔和下地壳的证据，研究扩张脊洋壳的成因。 我们的主要目标是限制（1）从地幔中提取熔体的多孔流动和/或断裂机制，以及（2）通过两种端元可能性的组合形成火成岩下洋壳：（a）单一岩浆房结晶作用加向下向外的韧性流动形成下地壳，（B）下地壳深成岩在许多小岩浆房中的结晶作用，这些岩浆房接近它们目前的侵位深度。 此外，我们试图解决有关的问题（3）熔体提取机制在下地壳，（4）变形机制和应变分配在下地壳，（5）岩浆冷却和结晶速率下的洋脊扩张的轴。