Localization of Melt Transport at Mid-Ocean Ridges

大洋中脊熔体输送的本地化

• 批准号: 0327588
• 负责人: Laurent Montesi
• 金额: $ 14.77万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-12-01 至 2005-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0327588&HistoricalAwards=false
• 关键词: Localization; Melt; Transport; Mid; Ocean

Seismic experiments and seafloor morphology indicate that the region of crustal accretion, where melts reaches the base of the crust, has a half width of ~ 2 km, whereas the zone of melt production by decompression melting is much broader. Somehow, melt becomes focused by a factor of ~ 50 as it ascends, yet no single mechanism that has been proposed fully explains this focusing. Under this award, the PI will follow several lines of investigation, to: 1) Improve the treatment of crystallization and melt-rock reactions in steady-state one-dimensional columns to better understand the permeability structure at the base of the thermal boundary layer 2) Explore the effects of lateral variations in the crystallization function and the viscosity field, due to the thermal structure at the base of the lithosphere 3) Revisit the large-scale flow models to include non-Newtonian rheology and the effect of porosity variations on viscosity.

地震实验和海底形态表明，熔体到达地壳底部的地壳增生区的半宽约为2公里，而减压熔融产生的熔体区则宽得多。不知何故，熔体在上升过程中变得集中了约50倍，但没有一种单一的机制可以完全解释这种集中。根据该奖项，PI将遵循几条调查路线，以：1）改进稳态一维柱中结晶和熔体-岩石反应的处理，以更好地理解热边界层底部的渗透率结构2）探索结晶函数和粘度场的横向变化的影响，由于岩石圈底部的热结构3）重新审视大尺度流动模型，以包括非牛顿流变学和孔隙度变化对粘度的影响。