水对圣卡洛斯橄榄石中α-β转变动力学的影响。

Effects of water on the alpha-beta transformation kinetics in san carlos olivine.

作者信息

Kubo T, Ohtani E, Kato T, Shinmei T, Fujino K

机构信息

T. Kubo and E. Ohtani, Institute of Mineralogy, Petrology, and Economic Geology, Faculty of Science, Tohoku University, Sendai 980-8578, Japan. T. Kato, Institute of Geoscience, University of Tsukuba, Tsukuba 305-0006, Japan. T. Shinmei a.

出版信息

Science. 1998 Jul 3;281(5373):85-7. doi: 10.1126/science.281.5373.85.

DOI:10.1126/science.281.5373.85

PMID:9651250

Abstract

In experiments at 13.5 gigapascals and 1030 degreesC, the growth rate of wadsleyite, which forms from transformation of olivine, was substantially enhanced by the presence of water. Wadsleyite had a low dislocation density and subgrain boundaries in wet runs. Water enhanced the dislocation recovery in wadsleyite and therefore caused inelastic relaxation of the localized pressure drop associated with the transformation, resulting in an increase of the growth rate in wet runs. These results imply that even a small amount of water of 0. 05 weight percent can weaken wadsleyite in the mantle.

摘要

在13.5吉帕斯卡压力和1030摄氏度的实验中，由橄榄石转变形成的瓦兹利石的生长速率因水的存在而大幅提高。在有水参与的实验中，瓦兹利石的位错密度较低且存在亚晶粒边界。水促进了瓦兹利石中的位错恢复，因此导致了与转变相关的局部压降的非弹性松弛，从而使有水参与的实验中的生长速率增加。这些结果表明，即使是0.05重量百分比的少量水也会削弱地幔中的瓦兹利石。