Experimental grain growth of quartz aggregates under wet conditions and its application to deformation in nature

Junichi Fukuda (1, 2, 3) , Hugues Raimbourg (1, 2) , Ichiko Shimizu (3) , Kai Neufeld (4) , Holger Stünitz (1, 4)

1 ISTO - Institut des Sciences de la Terre d'Orléans - UMR7327
2 Géodynamique - UMR7327
3 Department of Earth and Planetary Science [Tokyo]
4 UiT - The Arctic University of Norway [Tromsø, Norway]

Grain growth of quartz was investigated using two quartz samples (powder and novaculite) with water under pressure and temperature conditions of 1.0-2.5 GPa and 800-1100 • C. The compacted powder preserved a substantial porosity, which caused a slower grain growth than in the novaculite. We assumed a grain growth law of d n − d n 0 = k 0 f r H 2 O exp(−Q/RT)t with grain size d (µm) at time t (sec-onds), initial grain size d 0 (µm), growth exponent n, a constant k 0 (µm n MPa −r s −1), water fugacity f H 2 O (MPa) with the exponent r, activation energy Q (kJ mol −1), gas constant R, and temperature T in Kelvin. The parameters we obtained were n = 2.5 ± 0.4, k 0 = 10 −8.8±1.4 , r = 2.3 ± 0.3, and Q = 48 ± 34 for the powder and n = 2.9 ± 0.4, k 0 = 10 −5.8±2.0 , r = 1.9 ± 0.3, and Q = 60 ± 49 for the novaculite.

Domaines: Planète et Univers [physics]

Junichi Fukuda, Hugues Raimbourg, Ichiko Shimizu, Kai Neufeld, Holger Stünitz. Experimental grain growth of quartz aggregates under wet conditions and its application to deformation in nature. Solid Earth, 2019, 10 (3), pp.621-636. ⟨10.5194/se-10-621-2019⟩. ⟨insu-02143142⟩