Toshio Mizuta - Academia.edu (original) (raw)

Papers by Toshio Mizuta

Mining geology, Oct 30, 1986

The trace elements, such as Ba, Sr, and Rb, were systematically used to decipher the differentiat... more The trace elements, such as Ba, Sr, and Rb, were systematically used to decipher the differentiation pro cess of the Jurassic and Cretaceous granitic rocks of South Korea. From Ba, Sr, and Rb relationships of the Cretaceous granitic rocks in both Kyongsang basin and Ogcheon zone, it is suggested that the Cretaceous granitic rocks were mainly formed by fractional crystallization of parental magmas. Quartz diorite (Jindong granite) in the Kyongsang basin has the chemistry of crystallized melts, as opposed to cumulate-like chemistry. While, granodiorite, adamellite, and granite (Bulgugsa granite, masanite, hypersolvus granite, and Cretaceous granitic rocks in the Ogcheon zone) have the chemistry between crystallized melts and cumulus crystals. This fact suggests that perfect separation of cumulus crystals from intermediate and felsic melts is unlikely, and some trapped intercumulus melt may be anticipated.

Shigen-Chishitsu, Apr 28, 1994

Journal of the Geothermal Research Society of Japan, Apr 25, 1995

Shigen-Chishitsu, May 20, 2002

Mining geology, Apr 28, 1994

Journal of the Clay Science Society of Japan, Sep 13, 1996

Mining geology, Dec 31, 1990

Moderate amounts of data on the Jurassic granitoids in the Hida belt and South Korea have been ac... more Moderate amounts of data on the Jurassic granitoids in the Hida belt and South Korea have been accumulated. From the data presented, it will be seen that similarities and disssimilarities of the Jurassic granitoids between two regions. 1) Modal compositions of Jurassic granitoids are somewhat similar between the two regions; 2) radiometric ages, series, such as magnetite-and ilmenite series, initial strontium ratios, and REE patterns of the Jurassic granitoids between the two regions are different. The facts mean that source materials and genesis of the Jurassic granitoids between the two regions were different. The REE patterns suggest that the Jurassic granitoids of South Korea were derived by partial melting of lower crust or by fractional crystallization of hornblende from quartz dioritic magmas, whereas Jurassic granitoids in the Hida belt were mainly differentiated by the insitu fractional crystallization. From the difference in the initial strontium ratios between the two regions, it is suggested that the Jurassic granitoids in South Korea may have been situated in the continental side compared with the Jurassic granitoids in the Hida belt.

International Journal of PIXE, 1999

Chemical composition of the fluids in the fluid inclusions of quartz from the pegmatite veins of ... more Chemical composition of the fluids in the fluid inclusions of quartz from the pegmatite veins of the Yamaguchi W - Cu skarn deposit was measured by a combination of the crush-leach method in deionized water and chemical analysis using PIXE. Chemical composition of the fluids is characterized by a low molar ratio of Na/K and a high Cu concentration. The molar ratio of Cu /( Cu + Fe + Zn ) of the fluid inclusions is higher than that of massive sulfide deposits on the seafloor. The molar ratio of Cu /( Cu + Fe + Zn ) of the fluid inclusions is similar to the ratios of the vapor-rich fluid inclusions from the quartz-cassiterite veins hosted within the Mole Granite in New South Wales, Australia. The high Cu concentration in fluid inclusions of quartz associated with the pegmatite veins from the Yamaguchi deposit suggests that the fluid emanating from the Miyako granitic melt at the later stage of crystallization had a high Cu content.

Mining geology, Dec 28, 1988

To understand the mode of differentiation of granitic magmas of Southwest Japan, neutron activati... more To understand the mode of differentiation of granitic magmas of Southwest Japan, neutron activation analyses have been made to measure the trace element abundance of the granitic rocks. During plagioclase-quartz biotite fractionation, Ba and Rb enrich in successive solids and melt, while Sr is depleted. The incoming of K feldspar as a solid phase causes Ba to be depleted along with Sr in successively formed solids, while Rb continues to be enriched. As suggested by MCCARTHY and ROBB (1978), a change in liquidus mineralogy from plagioclase-quartz biotite to plagioclase-quartz-K-feldspar-biotite during the in situ fractional crystallization of a granitic magma has a marked effect on the abundance of and interrelationships between Ba, Rb and Sr. In general, trace element data from the granitic rocks of Southwest Japan fit the model well, although the observed scatter of the data is somewhat greater than predicted by simple variation in cumulus-intercumulus proportions-possibly due to a diffeence in Ba, Rb and Sr contents of original melts, to the effect of assimilation, and to the change in the Sr partition coefficients for plagioclase during cooling.

Mining geology, Aug 15, 1987

To understand the mode of differentiation of the granitic magmas of Southwest Japan, neutron acti... more To understand the mode of differentiation of the granitic magmas of Southwest Japan, neutron activation analyses have been made to measure the REE abundance of the granitic rocks. We employed the Rayleigh fractionation model to simulate the crystallization of the granitic melts. Since the model calculations fit the observed REE data for the granitic rocks well, it is suggested that the granitic rocks of Southwest Japan were mainly differentiated by fractional crystallization. On the basis of the model calculations, it is also suggested that the granitic rocks with a large negative Eu anomaly found near some tungsten deposits are residues of an extremely differentiated magma.

Journal of the Society of Materials Engineering for Resources of Japan, 2002

GSA Annual Meeting in Denver, Colorado, USA - 2016, 2016

Journal of Geochemical Exploration, Sep 1, 2008

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