17:15 〜 18:30
[PPS05-P06] 月の溶岩の粘度
キーワード：粘度、回転粘度計、チタン、組成依存性
Viscosity is a parameter related to magma flow and mechanism of eruption, which is considered to be affected by SiO2 and TiO2. Lunar basalt contains more titanium and iron than Earth's volcanic rock. This is because ilmenite-rich layer was also melted together when basaltic layer beneath the crust re-melted (Shearer and Papike, 1999). Therefore, the viscosity of lunar basaltic magma is thought to be greatly influenced by TiO2.
In this study, we measured the viscosity of three lunar volcanic glasses, Apollo 14 black glass, Apollo 15 green glass-C, and Apollo 17 orange glass (74220), and discussed the effect of composition on viscosity. Viscosity measurements were performed using a rotational viscometer in the range of 1500℃ to 1270℃ in argon.
It has been found that the viscosity of the magma decreases with increasing TiO2 content (Zhang and Jahanshahi, 2004). However the lowest viscosity in this measurement was not Apollo 14 black glass with the highest TiO2 content (16.4 wt%), but Apollo 17 orange glass with an intermediate TiO2 content (9.12 wt%). TiO2 works to reduce viscosity, but if its content exceeds a certain amount (perhaps about 10 wt%), its ability to reduce viscosity decreases, and other compositions may be more effective at reducing viscosity.
In this study, we measured the viscosity of three lunar volcanic glasses, Apollo 14 black glass, Apollo 15 green glass-C, and Apollo 17 orange glass (74220), and discussed the effect of composition on viscosity. Viscosity measurements were performed using a rotational viscometer in the range of 1500℃ to 1270℃ in argon.
It has been found that the viscosity of the magma decreases with increasing TiO2 content (Zhang and Jahanshahi, 2004). However the lowest viscosity in this measurement was not Apollo 14 black glass with the highest TiO2 content (16.4 wt%), but Apollo 17 orange glass with an intermediate TiO2 content (9.12 wt%). TiO2 works to reduce viscosity, but if its content exceeds a certain amount (perhaps about 10 wt%), its ability to reduce viscosity decreases, and other compositions may be more effective at reducing viscosity.