Rheological properties of composite serpentine-brucite suspensions: Implications for mudflow behavior on forearc seamounts
Rheological properties of composite serpentine-brucite suspensions: Implications for mudflow behavior on forearc seamounts
复制标题
DOI：
10.1016/j.margeo.2018.06.004
复制
发表时间：
2018-09-01
期刊：
影响因子：
2.9
通讯作者：
Hirauchi, Ken-ichi
中科院分区：
文献类型：
--
作者：
Kameda, Jun;Hirauchi, Ken-ichi
为了更好地了解影响海底蛇纹岩泥流的因素，例如最近在马里亚纳海山记录的因素，我们在7摄氏度和0.6 M盐浓度下对复合蛇纹岩-水镁石悬浮液进行了流变学测量。通过宾汉流体模型拟合得到的流动曲线，由此确定每种悬浮液的宾汉屈服应力和塑性粘度。随着悬浮液含水量的降低，屈服应力和塑性粘度均增大。增加固体混合物中的水镁石分数导致屈服应力的增加和相同的水/固体比的悬浮液的粘度的降低。物理化学参数，如pH值，温度和电解质浓度也适度影响悬浮液的流变学，但影响不像以前观察到的含有蒙脱石的悬浮液。结果表明，蛇纹岩泥的矿物组成，特别是丰富的水镁石，有尽可能多的影响，如在马里亚纳海山观察到的可变泥流行为的含水量。
To better understand the factors that influence seafloor serpentinite mudflows, such as those recently documented on the Marianas seamounts, we have conducted rheological measurements on composite serpentine-brucite suspensions at 7 degrees C and a salt concentration of 0.6 M. The resulting flow curves were fitted by the Bingham fluid model, from which the Bingham yield stress and plastic viscosity of each suspension was determined. Both the yield stress and plastic viscosity increase as the water content of the suspension decreases. Increasing the brucite fraction in the solid mixture results in an increase in yield stress and a decrease in viscosity of the suspension for the same water/solid ratio. Physicochemical parameters such as pH, temperature and electrolyte concentration also moderately affect the rheology of the suspension, but the influence is not as significant as has been previously observed for suspensions containing smectite. The results suggest that mineral composition of the serpentinite mud, especially the abundance of brucite, has as much of an impact as water content on variable mudflow behaviors such as those observed at the Mariana seamounts.