• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Contributions to Mineralogy and Petrology >The temperature dependence of water solubility in enstatite
【24h】

The temperature dependence of water solubility in enstatite

机译：顽辉石中水溶性的温度依赖性

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The solubility of water in pure enstatite was measured on samples synthesized under water-saturated conditions at 15 kbar and temperatures ranging from 700 to 1,100 deg C. Polarized FTIR measurements on millimetre-sized, clear crystals showed that water solubility increases strongly with temperature, from 101 ppm by weight at 700 deg C to 269 ppm by weight at 1,100 deg C. The position and shape of the infrared bands hardly changes with temperature, with one notable exception: a band close to 3,380 cm~(-1) is present in samples synthesized between 700 and 1,000 deg C, while this band is absent from samples synthesized at 1,100 deg C. This effect appears to be very reproducible and points towards a slight change in the crystal structure of enstatite between 1,000 and 1,100 deg C at 15 kbar. The water solubility data of this study as well as those of Rauch and Keppler (Contrib Mineral Petrol 143:525-536, 2002) can be reproduced by the equation. K = A f_(H_2O) exp(-DELAT H~(1 bar)/RT) exp(-DELAT V~(solid) P/RT), where K is water solubility, f_(H_2O) is water fugacity, A is 0.01354 ppm/bar, DELAT V~(solid) = 12.1 cm~3/mol is the volume change of enstatite during incorporation of water, and DELAT H~(1 bar)= -4,563 J/mol is the reaction enthalpy at 1 bar. This equation predicts the following behaviour of water solubility in enstatite as a function of pressure and temperature: (1) water solubility increases with pressure up to a maximum around 80 kbar; (2) water solubility decreases with temperature at 1 bar; and (3) water solubility increases with temperature between 10 and 100 kbar. If the observed temperature dependence for enstatite were representative for other upper mantle minerals as well, it would have the following implications: (1) Lateral temperature gradients in the upper mantle could cause major variations in water contents at the same depth; in particular, hot mantle plumes may scavenge water from the surrounding shallow upper mantle. (2) The scavenging of water by hot plumes could be a major factor in increasing the mobility of plumes. (3) The predicted temperature dependence of water solubility at the base of the upper mantle may allow plumes to bypass the transition zone water filter postulated by Bercovici and Karato (Nature 425:39-44, 2003).
机译：在15kbar的水饱和条件和700至1,100℃的温度下，在水饱和条件下合成的样品上测量了水在纯顽辉石中的溶解度。在毫米级透明晶体上进行的FTIR极化测量表明，从在700摄氏度下为101重量ppm至在1100摄氏度下为269 ppm重量。红外波段的位置和形状几乎不会随温度变化，唯一值得注意的例外是：在其中存在接近3,380 cm〜（-1）的波段在700到1,000摄氏度之间合成的样品，而在1,100摄氏度下合成的样品中不存在该谱带。这种效果似乎非常可重现，并指出在15 kbar下在1,000到1,100摄氏度之间顽辉石的晶体结构略有变化。该研究以及Rauch和Kepppler的水溶性数据（Contrib Mineral Petrol 143：525-536，2002）可以由等式再现。 K = A f_（H_2O）exp（-DELAT H〜（1 bar）/ RT）exp（-DELAT V〜（固体）P / RT），其中K为水溶性，f_（H_2O）为水逸度，A为0.01354 ppm / bar，DELAT V〜（固体）= 12.1 cm〜3 / mol是掺入水期间顽辉石的体积变化，而DELAT H〜（1 bar）= -4,563 J / mol是1 bar时的反应焓。该方程式预测了在顽辉石中水溶性随压力和温度变化的以下行为：（1）水溶性随着压力的增加而增加，最高可达到80 kbar。 （2）1 bar时，水溶性随温度降低而降低; （3）水溶性随着温度在10至100 kbar之间而增加。如果观察到的顽辉石对温度的依赖性也可以代表其他上地幔矿物，则将具有以下含义：（1）上地幔的侧向温度梯度可能导致相同深度处的含水量发生重大变化;特别是热的地幔柱可能会清除周围浅层上地幔中的水。 （2）热羽流对水的清除可能是增加羽流活动性的主要因素。 （3）上地幔底部水溶性的预测温度依赖性可能使羽流绕过Bercovici和Karato假定的过渡带滤水器（自然425：39-44，2003）。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号