JpGU-AGU Joint Meeting 2017

Presentation information

[EE] Poster

S (Solid Earth Sciences) » S-IT Science of the Earth's Interior & Tectonophysics

[S-IT22] [EE] Interaction and Coevolution of the Core and Mantle in the Earth and Planets

Sun. May 21, 2017 1:45 PM - 3:15 PM Poster Hall (International Exhibition Hall HALL7)

convener:Taku Tsuchiya(Geodynamics Research Center, Ehime University), Hidenori Terasaki(Graduate School of Science, Osaka University), Madhusoodhan Satish-Kumar(Department of Geology, Faculty of Science, Niigata University), Tetsuo Irifune(Geodynamics Research Center, Ehime University), John Hernlund(Earth-Life Science Institute, Tokyo Institute of Technology), Eiji Ohtani(Department of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University)

[SIT22-P17] Viscosity and atomic-local-structures of basaltic melt under high pressure

*Satoshi Ohmura1, Taku Tsuchiya2 (1.Hiroshima Inst. of Tech., 2.Ehime Univ.)

Keywords:Ab initio molecular dynamics simulation, Basaltic melt, Viscosity , Microscopic structures

High pressure properties of basaltic melt are of importance in deep Earth science related to such as early magma ocean and subsequent differentiation processes (Agee 1998; Ohtani and Maeda 2001; Suzuki, et al. 2005)
Recently, experimental studies reported that the viscosity of basaltic melt decreases with increasing pressure (Allwardt, et al. 2007; Sakamaki, et al. 2013). They suggested based on the results of classical molecular dynamics simulation (Nevins and Spera 1998) and 27Al magic-angle spinning nuclear magnetic resonance (Allwardt, et al. 2007) that this anomalous behavior is related to the coordination change of Al. However, other silicate melts which contain none of Al also show a common behavior of viscosity (McMillan et al., 2009 ). It means that the microscopic origin of the anomalous pressure response of viscosity of the basaltic melt is still unclear. For this reason, in this study, we perform ab initio molecular dynamics simulations and analyze atomic–local-structures in basaltic aluminosilicate melt under pressure. At the last meeting, we reported the structural changes around Al atom. This time, we discuss relationship between the viscosity and structural changes not only around Al but other elements.

C. B. Agee, Phys, Earth Planet. Inter. 107, 63 (1998)
E Ohtani and M. Maeda, Earth Planet. Sci. Lett. 193, 69 (2001)
A. Suzuki, et al. Phys. Chem. Miner. 32, 140 (2005)
D. Nevins and F. Spera, Am. Mineral. 83 1220 (1998)
J. R. Allwardt, et al. Am. Mineral. 92, 1093 (2007)
P. E. McMillan and M. C. Wilding. J. Non-Cryst. Solids. 355 722 (2009)
T. Sakamaki, et al. Nature Geoscience 6, 1041 (2013)