Creep of Pyroxene Single Crystals

辉石单晶的蠕变

• 批准号: 8720976
• 负责人: Stephen Mackwell
• 金额: $ 5.06万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-06-01 至 1991-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8720976&HistoricalAwards=false
• 关键词: Creep; Pyroxene; Single; Crystals

A suite of high-temperature creep experiments will investigate the rheology of single crystals of clinopyroxene (diopside and hedenbergite) and orthopyroxene (bronzite and enstatite) under carefully-controlled thermodynamic conditions at 1 atm. total pressure, to determine intracrystalline flow laws and mechanisms of deformation appropriate to these minerals for extrapolation to upper mantle conditions. In particular, the dependence of creep rate on oxygen partial pressure and on the activity of silica will be measured. Olivine is generally regarded as both the most abundant and weakest mineral in the upper mantle, so that the rheology of the upper mantle is usually modelled using the results of high-temperature deformation experiments on olivine single crystals and polycrystals. However, in a chemically heterogeneous mantle, deformation in regions with a locally high pyroxene content, such as subduction zones, will be controlled by the deformation of pyroxenes.

一套高温蠕变实验将 单斜辉石单晶流变学研究 （透辉石和铁辉石）和斜方辉石（古铜岩和 顽火辉石）在严格控制的热力学条件下， 1大气压总压力，以确定晶内流动规律， 适合这些矿物的变形机制， 外推到上地幔条件。 特别是 蠕变速率对氧分压和 将测量二氧化硅的活性。 橄榄石一般 被认为是最丰富和最弱的矿物在 上地幔，因此上地幔的流变学通常是 使用高温变形的结果建模 橄榄石单晶和多晶的实验。 然而，在这方面， 在化学性质不均匀的地幔中， 局部高辉石含量，如俯冲带， 由辉石的变形控制。