Formation of ultrafine particles from impact-generated supercritical water
Formation of ultrafine particles from impact-generated supercritical water
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DOI：
10.1016/j.epsl.2007.04.014
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发表时间：
2007-06
影响因子：
5.3
通讯作者：
Y. Furukawa;H. Nakazawa;T. Sekine;T. Kakegawa
中科院分区：
文献类型：
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作者：
Y. Furukawa;H. Nakazawa;T. Sekine;T. Kakegawa
针对橄榄石、铁和水的混合物进行了冲击回收实验，以模拟低速海洋撞击事件。在实验过程中，样品容器中的最大压力达到20 GPa。橄榄石和金属氧化物的超细颗粒（UPs）是新形成的，即使在压力小于其汽化压力（150-200 GPa）。阻抗匹配和热力学计算表明，超临界水形成的冲击波穿越。这种超临界水溶解受冲击的材料并沉淀UP。我们的实验结果进一步表明，许多撞击海洋的外星物体可能已经转化为大量的UPs，并可能影响气候和紫外线屏蔽，特别是在Hadean晚期和太古代早期。
Shock-recovery experiments were performed targeting an olivine, iron, and water mixture to simulate a low-velocity ocean impact event. The maximum pressure in the sample container reached 20 GPa during the experiments. Ultrafine particles (UPs) of olivine and metal oxides were newly formed, even at pressures less than their vaporization pressure (150–200 GPa). Impedance-match and thermodynamic calculations suggest that supercritical water formed during the shock wave traversal. Such supercritical water dissolves impacted materials and precipitates UPs. Results of our experiments further suggest that many extraterrestrial objects that have impacted on oceans might have been converted to large masses of UPs and probably influenced the climate and UV shielding, especially during the late Hadean and early Archean eras.