[S-SS14] 地震発生の物理・断層のレオロジー

[SSS14-P02] 石英ガウジの摩擦特性に対する滑石含有量の影響

白鬚 里彩子¹、多々良 祈里¹、*平内 健一¹、竹村 貴人² (1.静岡大学理学部地球科学科、2.日本大学文理学部地球科学科)

キーワード：摩擦、スティック・スリップ、断層弱化、層状珪酸塩

Phyllosilicates have low coefficients of friction and an effect of weakening fault strength. To understand effects of talc content on frictional strength and sliding stability, we conducted frictional sliding experiments on dry gouge mixtures of quartz and talc at room humidity, room temperature, a normal stress of 10 MPa and sliding velocities of 0.66–2 µm/s, using a single direct-shear apparatus. The coefficient of friction for the mixture ranged from 0.18 to 0.69 and fell between pure quartz and talc values. The overall trend was a decrease in the coefficient of friction with increasing talc content. The velocity dependence of friction, (a−b), ranged from −0.0018 to 0.0039 and increased with increasing talc content. The (a−b) values are highest in the mixture with a talc content of 80 wt.%. For the mixture with talc contents below 10 wt.%, the (a−b) values become negative, with the occurrence of slow to fast stick-slip behavior.