High-Pressure Melting of Subducted Oceanic Crust: Characterizing the Major- and Trace-Element Signatures of Slab Melts Using a Modified Diamond-Aggregate Technique

俯冲洋壳的高压熔融：使用改进的金刚石骨料技术表征板状熔体的主要元素和微量元素特征

• 批准号: 9706254
• 负责人: Edward Stolper
• 金额: $ 32.84万
• 依托单位: California Institute of Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-07-15 至 2001-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9706254&HistoricalAwards=false
• 关键词: Pressure; Melting; Subducted; Oceanic; Crust

9706254 Stolper The goals of this project are (1) to develop an experimental data base at 25 and 30 kbar characterizing the major element compositions of vapor-undersaturated liquids produced by near-solidus melting of subducted, hydrated mid-ocean ridge basalt (MORB) beneath island arcs; (2) to determine whether hydrous near-solidus in equilibrium with an eclogite residue are interconnected at low melt fractions, which is important for understanding whether these liquids can be extracted from the slab into the overlying mantle wedge; and (3) to determine the partitioning of high field strength (HFS) and rare earth elements (REE) between clinopyroxene, garnet, and near-solidus melts. The experiments proposed here will expand the ability to model the geochemical signature of near-solidus slab melts and hoe this signature would alter the mantle and be expressed in erupted lavas from convergent margins.

该项目的目标是：（1）建立一个25和30 kbar的实验数据库，以表征岛弧下俯冲的水合洋中脊玄武岩（MORB）近固相线熔融产生的蒸汽-不饱和液体的主要元素组成;（2）确定与榴辉岩残余物平衡的含水近固相线在低熔体分数下是否相互连通，这对于理解这些液体是否可以从板块中提取到上覆地幔楔中是重要的;（3）确定高场强（HFS）和稀土元素（REE）在单斜辉石、石榴石和近固相线熔体之间的分配。 这里提出的实验将扩大模拟近固相线板状熔体的地球化学特征的能力，并且这种特征将改变地幔，并在会聚边缘的喷发熔岩中表达。