Elasticity of Iron-bearing Mantle Minerals

含铁地幔矿物的弹性

• 批准号: 0711591
• 负责人: J Brown
• 金额: $ 40万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0711591&HistoricalAwards=false
• 关键词: Elasticity; Iron; bearing; Mantle; Minerals

The investigators are undertaking velocity measurements on lower mantle constituents in order to better understand the impact of the high-spin to low-spin (HSLS) electronic transition on lower mantle seismic profiles. They will measure velocities using Impulsive Stimulated Light Scattering on samples loaded in diamond anvil cells. The team seeks to characterize derivatives in velocity of ferro-periclase caused by changes in electronic configuration, iron content, temperature and pressure. These results will be interpreted within the context of Earth's deep mantle through further extension and application of the theory for the transition. Ultimately, elastic constants for ferro-periclase should be measured under mantle conditions of temperature in excess of 1000K as well as pressure. However, a reasonable goal in the near term will be to undertake high-pressure studies under modest conditions of heating and cooling. A quantitative validation of predictions under experimentally accessible conditions of temperature would lend confidence in the extrapolation to mantle temperatures. The successful characterization of elastic properties through the HSLS transition in iron-bearing silicate perovskites remains a longer term goal. Challenges include obtaining samples of sufficient quality to undertake the experiments. The project includes training of a graduate student.

研究人员正在对下地幔成分进行速度测量，以便更好地了解高自旋到低自旋（HSLS）电子跃迁对下地幔地震剖面的影响。他们将使用脉冲受激光散射来测量装载在金刚石砧室中的样品的速度。该团队试图表征由电子构型、铁含量、温度和压力变化引起的方镁石铁速度的导数。这些结果将通过进一步扩展和应用转变理论在地球深层地幔的背景下进行解释。最终，方镁石铁的弹性常数应在超过 1000K 的温度和压力的地幔条件下测量。然而，近期的合理目标是在适度的加热和冷却条件下进行高压研究。在实验可达到的温度条件下对预测进行定量验证将为外推地幔温度提供信心。通过含铁硅酸盐钙钛矿的 HSLS 转变成功表征弹性性能仍然是一个长期目标。 挑战包括获取足够质量的样本来进行实验。该项目包括培养一名研究生。