Rheology, Attenuation, and Melt Migration in Partially Molten Mantle Rocks

部分熔融地幔岩石的流变、衰减和熔融迁移

• 批准号: 8916438
• 负责人: David Kohlstedt
• 金额: $ 23.2万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-01 至 1993-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8916438&HistoricalAwards=false
• 关键词: Rheology; Attenuation; Melt; Migration; Partially

The PI will investigate hotspots and mid-oceanic ridges to constrain their underlying physical processes, mainly heat and mass transfer. His investigation of hotspots has confirmed that these features are produced by mantle plumes. In particular, the shape of hotspots swells, such as that hear Hawaii, is simply related to the kinematics of flow from plumes. He has constrained the heat and mass fluxes of plumes globally. He will now extend this work to learn more about how plumes work and about the dynamics of heat transfer between the plume and the lithosphere. Some variations in the mantle temperature beneath ridge axes may be related to ambient temperature variations at mid-mantle depths, not plumes. His studies of ridge axes will concentrate on modeling features affected by temperature variations associated with hotspots, such as central rifts. He will continue to study temperature variations associated with hydrothermal circulation with emphasis on the downwelling parts of the circulation nearest to the ridge axis. He will reprocess multichannel seismic data from the back-arc Valu Fa ridge near Tonga to constrain the location of the crustal magma chamber, including one line across an overlapping spreading center.

PI将调查热点和大洋中脊，以限制其潜在的物理过程，主要是热量和质量传输。他对热点的调查证实，这些特征是由地幔热柱产生的。特别是，热点膨胀的形状，如听到夏威夷，只是与羽状流的运动学有关。他在全球范围内限制了羽流的热流和质量流。他现在将扩展这项工作，以了解更多关于羽流如何工作以及羽流和岩石圈之间的热传递动力学的知识。地脊轴线以下地幔温度的某些变化可能与中地幔深处的环境温度变化有关，而不是与羽流有关。他对山脊轴的研究将集中在建模受与热点相关的温度变化影响的特征上，例如中央裂缝。他将继续研究与热液环流有关的温度变化，重点是最接近脊轴的环流下流部分。他将重新处理汤加附近弧后Value Fa山脊的多道地震数据，以限制地壳岩浆室的位置，包括一条横跨重叠扩张中心的线。