2000 Fiscal Year Final Research Report Summary
Structural and Chemical study on magma crystallization and mineral melting processes.
Grant-in-Aid for Scientific Research (B).
|Allocation Type||Single-year Grants|
Petrology/Mineralogy/Science of ore deposit
|Research Institution||KANAZAWA UNIVERSITY|
OKUNO Masayuki Kanazawa Unversity, Faculty of Science, Associate professor, 理学部, 助教授 (40183032)
TORAMARU Atsushi Kanazawa Unversity, Graduate School of Natural Science and Technology, Associate professor, 自然科学研究科, 助教授 (50202205)
ISHIWATARI Akira Kanazawa Unversity, Faculty of Science, Associate professor, 理学部, 助教授 (90184572)
KIHARA Kuniaki Kanazawa Unversity, Faculty of Science, Professor, 理学部, 教授 (70019503)
|Project Period (FY)
1998 – 2000
|Keywords||magma / glass / crystallization / melting / structural analysis / IR spectroscopy / Raman spectroscopy / X-ray diffraction method|
Principle results on the study on magma crystallization and mineral melting processes were followed.
a) Structural studies of glasses
Firstly, The glass structures of Al_2O_3-SiO_2 system that is one of the principle components of magma were analyzed. Many Al atoms in these glasses have tetrahedra and the number of octahedral Al may be small. This result is consistent with the model structure derived from Monte Carlo Simulation. The structures of feldspar (NaAlSi_3O_8-CaAl_2Si_2O_8) glasses were also analyzed. From the observations, it was evident that the density increase and molar volume decrease with increases of Ca and Al atoms could be explained by decrease of T-O-T angle (T=Si, AL) in the glass structure.
b) Study on crystallization of silicate melt
Sb rich μ size crystals in cathode ray tube glass were investigated by X-ray diffraction and Raman spectra measurements and revealed that this crystal had romeite type structure. The structure Sb rich glass phase surrounding romeite crystal was also analyzed. It was evident that the network structure of this glass was rather distorted and this distortion may relate to crystallization of romeite. The structure of natural volcanic glass (onsidian) which had liquid and small crystalline phases was also analyzed. Obtained results show that this obsidian has sub-μ size phase which is not included normal liquid phase. This phase may be related in crystallite phase in obsidian. Numerical experiments on crystallization for binary silicate system were adopted for study on formation process of textures of volcanic rocks. The texture differences between volcanic and plutonic rocks may be caused by their different cooling rate.
c) These results were discussed by all project members and we prepared some scientific papers.
Research Products (26results)