Obsidian‐H2O viscosities at 1000 and 2000 bars in the temperature range 700° to 900°C
Obsidian‐H2O viscosities at 1000 and 2000 bars in the temperature range 700° to 900°C
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700° 至 900°C 温度范围内 1000 和 2000 bar 下的黑曜石-H2O 粘度
DOI：
10.1029/jz068i023p06337
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发表时间：
1963
影响因子：
--
通讯作者：
H. R. Shaw
中科院分区：
文献类型：
--
作者：
H. R. Shaw
合成水合黑曜石的粘度已通过落球技术在两个 H2O 含量值下测量。按重量计，水含量为 4.3% 时，粘度的常用对数泊范围为 800°C 时的 6.51 至 900°C 时的 5.88，水含量为 6.2% 时，粘度的常用对数泊范围为 700°C 时的 6.54 至 850°C 时的 5.25。实验表明，在这些温度下压力对粘度的影响很小。这些数据与 Friedman、Long 和 Smith 在 H2O 含量为 1.25% 时对流纹岩玻璃测定的粘度等温线一致。活化能和指前常数由这项工作和弗里德曼等人的工作确定。显示出与二元碱金属氧化物-二氧化硅系统的数据惊人的相似性。这表明Bockris及其同事提出的硅酸盐熔体离散离子理论适用于硅酸盐-H2O体系。在此模型的基础上，给出了一个通用图表，该图表允许近似预测骨架硅酸盐-H2O系统的粘度，其中H2O含量按重量计高达约10%，温度在500°C至1200°C范围内。
Viscosities of synthetically hydrated obsidians have been measured by the falling-sphere technique at two values of the H2O content. At 4.3 per cent H2O, by weight, the common logarithm of the viscosity in poises ranges from 6.51 at 800°C to 5.88 at 900°C, and at 6.2 per cent H2O from 6.54 at 700°C to 5.25 at 850°C. The effect of pressure on the viscosity is shown experimentally to be slight at these temperatures. The data are consistent with viscosity isotherms determined by Friedman, Long, and Smith on rhyolite glass at H2O contents to 1.25 per cent. Activation energies and pre-exponential constants determined from this work and that of Friedman et al. show striking similarities to data for binary alkali oxide-silica systems. This suggests that the discrete ion theory of silicate melts proposed by Bockris and co-workers is applicable to silicate-H2O systems. On the basis of this model a generalized graph is presented which permits approximate predictions of viscosities of framework silicate-H2O systems for H2O contents up to about 10 per cent by weight and temperatures in the range 500° to 1200°C.