The Electrical Resistivity of the Main Minerals in Ultramafic Rock, Eclogite and Gabbro under High Pressures
-
摘要: 为了研究3~20 GPa压力范围内地幔物质的电阻率随压力变化的情况，选择了辉长岩、榴辉岩和二辉橄榄岩中的主要矿物：单斜辉石、拉长石、绿辉石、石榴石和顽辉石作研究对象，在DAC装置中测定其在不同压力下的电阻率。结果表明，在3~8 GPa压力区间，矿物的电阻率随压力增高而明显增大。超过8 GPa，电阻率受压力的影响减小，而辉石的电阻率随压力增高而不同程度地减小，在14~20 GPa压力范围内，顽辉石的电阻率再次随压力增高而明显增大，对其它矿物的影响不明显。在约400 km深处的地幔中出现的电导率突然上升，恰好发生在辉石电阻率与压力成负相关的压力范围内（12 GPa左右），这是否是一种巧合，将在以后研究。Abstract: Clinopyroxene, Labrador, omphacite, garnet and enstatite as the main minerals in ultramafic rock, eclogite and gabbro are selected as the samples to study the variations of resistivity of the mantl materials with pressures between 3 GPa and 20 GPa using a DAC device. The results indicated that the resistivities of these minerals increase obviously with pressures between 3 and 8 GPa, the effect of the pressure is reduced, and the resistivities of pyroxenes decrease with the pressure in variety of degrees. In the range of 14 to 20 GPa, the resistivity of enstatite increases obviously again with pressure, but the other minerals do not increase so clearly. In the mantle, in the depth of about 400 km, sudden increase of the conductivity was presented (McDonald, 1975), and the negative correlation between the resistivity of pyroxene and the pressure occurs just under this pressure (about 12 GPa). Is that a coincidence? It is a problem we shall study later.
-
Key words:
- Mantle mineral /
- high pressure resistivity /
- DAC device
-
Parkhomenko E I. Reviews of Geophysics and Space Physics, 1982, 20(2): 193. Mao H K. Carnegie Institution of Washington Year Book, 1973, 72: 552. 胥怀济, 郭金弟. 地震地质, 1985, 7(4): 41. Parkhomenko E L. Physical Properties of Rocks and Minerals under Extreme P.T-Conditions. Ed by Stiller H, Volarovich M P, 1979: 107. Ringwood A E. 地幔的成分与岩石学. 地震出版社, 1981: 197-198. -
点击查看大图
计量
- 文章访问数: 8093
- HTML全文浏览量: 1854
- PDF下载量: 729
下载:
