Japan Geoscience Union Meeting 2015

Presentation information


Symbol S (Solid Earth Sciences) » S-CG Complex & General

[S-CG57] Structure, evolution and dynamics of mobile belts

Wed. May 27, 2015 6:15 PM - 7:30 PM Convention Hall (2F)

Convener:*Toru Takeshita(Department of Natural History Sciences, Graduate School of Science, Hokkaido University), Hiroshi Sato(Earthquake Prediction Research Center, Earthquake Research Institute, The University of Tokyo), Koichiro Obana(Research and Development Center for Earthquake and Tsunami, Japan Agency for Marine-Earth Science and Technology), Takuya NISHIMURA(Disaster Prevention Research Institute, Kyoto University), Yukitoshi Fukahata(Disaster Prevention Research Institute, Kyoto University), Aitaro Kato(Graduate School of Environmental Studies, Nagoya University), Jun Muto(Department of Earth Sciences, Tohoku University), Katsushi Sato(Division of Earth and Planetary Sciences, Graduate School of Science, Kyoto University), Shuichi Kodaira(Institute for Research on Earth Evolution Japan Agency for Marine-Earth Science and Technology), Takeshi Sagiya(Disaster Mitigation Research Center, Nagoya University), Tatsuya Ishiyama(Earthquake Research Institute, University of Tokyo), Makoto MATSUBARA(National Research Institute for Earth Science and Disaster Prevention), Yasutaka Ikeda(Department of Earth and Planetary Science, Graduate School of Science, University of Tokyo)

6:15 PM - 7:30 PM

[SCG57-P11] Grain growth of nanocrystalline labradorite

*Satoko HONDA1, Masahiro ISHIKAWA1 (1.Yokohama National University)

Plagioclase is a solid solution series that ranges from albite to anorthite endmembers (with respective compositions NaAlSi3O8 to CaAl2Si2O8). Plagioclase is a major constituent mineral in the Earth's crust. Its physical and chemical properties are important for establishing the overall rheology of Earth's crust. Previous experimental studies on sintering on plagioclase were mostly concentrated on the endmembers under the high-pressure conditions, thus there are few reports on sintering of plagioclase with intermediate composition.
In this study, sintering of labradorite polycrystalline were performed by using nanoscale powders of natural labradorite, and grain growth kinetics was studied in sintered polycrystalline labradorite. We prepared nanoscale mineral powders from natural crystals of labradorite (Ab38An62) by milling. Sintering experiments were carried out at a temperature of 1100-1210 ℃ with controlling time after milling and formed mineral powders. Starting materials were characterized by electron probe micro analysis (EPMA). The resultant materials were characterized by X-ray powder diffraction (XRD), secondary electron microscope (SEM) and Xray fluorescence (XRF) analysis.
Grain growth occurred with increasing sintering temperature or sintering time. The experimental data can be fit the following relation, Dfn-D0n = kt where n is a constant, Df and D0 are the grain size at time t = t and t = 0 respectively, and k is a rate constant. For sintering, a temperature of 1100-1210 ℃ with controlled time can provide high dense aggregates of labradorite with an average grain size of 0.5micro m, porosity of 3vol% and volume reduction of 60%. In this study, we found that high dense and fine grain polycrystalline Labradorite can be made from nano-sized powders (<100nm) by atmospheric pressure sintering.