中部モンゴルツアガンツアイルウルの深成岩の地質学的岩石学的研究

Geological, petrographical and geochemical characteristics of the Baidrag granite pluton from the Tsagaan Tsahir Uul area can be summarized as following; The granitic complex is composed of two types of granites, distinguished by its biotite content. The modal abundance of biotite varies gradually between the two rock types. Major and trace element geochemical characteristics of the granitic rocks are similar, but they differ by SiO_2 content. FeO, CaO, Sr, and Ba contents of the biotite granite are slightly higher than those of the two mica granite. Both granites are medium to high potassium calc alkaline, and have peraluminous chemical features. Studied mineralogical composition and major and trace element geochemistry show that the granitic rock of Tsagaan Tsahir Uul area has volcanic arc granite (VAG) characteristics.論文Articl

A new route for the synthesis of methacrylic acid from 2-methyl-1,3-propanediol by integrating biotransformation and catalytic dehydration

Methacrylic acid was produced in high yield by an integrated process involving bioconversion of 2-methyl-1,3-propanediol (2M1,3PD) to 3-hydroxy-2-methylpropionic acid (3H2MPA) via 3-hydroxy-2-methylpropanal (3H2MPAL), and catalytic dehydration of the resulting acid. Whole cells of Gluconobacter oxydans grown on glycerol-based culture medium were used as the catalyst for oxidative biotransformation that involved alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) enzymes in the organism. The effect of several reaction parameters on bioconversion in a batch system was investigated to obtain 95–100% conversion of 2M1,3PD with over 95% selectivity to 3H2MPA. The optimum conditions for bioconversion were pH 6–7.5, 25–30 °C, 5–10 g substrate and 2.6 g cell (dry weight) per liter. Higher substrate concentrations led to enzyme inhibition and incomplete conversion. Loss of catalytic activity was noted during recycling of the cells. The cells were active for a longer period when used for biotransformation of 20 g per L of substrate in a continuous reactor with cell retention. The product of the bio-oxidation, 3H2MPA, was converted using titanium dioxide at 210 °C to give methacrylic acid (MA) with a yield of over 85%. The integrated process provides a new environmentally benign route for production of methacrylic acid from 2-methyl-1,3-propanediol, an industrial by-product, compared with the conventional acetone-cyanohydrin (ACH) process

Geology, Mineralization and Magma Evolution of the Zuun Mod Mo-Cu Deposit in Southwest Mongolia

Zuun Mod is a Porphyry-Type Mo-Cu Deposit Located in the Edren Terrane in Southwest Mongolia. the Deposit Has Estimated Resources of 218 Mt with an Average Mo Grade of 0.057% and Cu Grade of 0.069%, and Significant Amounts of Re. the Deposit is Characterized by Multiple Pulses of Magmatism and Exsolution of Magmatic Ore Fluids and Associated Alteration and Mineralization. the Timing of These Events and the Tectonic Environment Were Unconstrained, and the Deposit\u27s Origin Remains Controversial. based on Drill Core and Field Examinations, Four Lithological Units of the Bayanbulag Intrusive Complex Are Identified in the Deposit Area Including Quartz Syenite, Quartz Monzonite, Granodiorite, and Granite. the Majority of Mo Mineralization at Zuun Mod Occurs in Sheeted and Stockwork Quartz Veins that Crosscut Units of the Bayanbulag Complex as Well as Disseminations within Altered Granitoids Wherein the Mineralized Quartz Veins Occur with Potassic and Phyllic Alteration Selvages. Zircon U-Pb Age Dating for Quartz Monzonite and Granodiorite Defined the Timing of Magmatic Events at 305.3 ± 3.6 Ma and 301.8 ± 2.7 Ma, Respectively. Molybdenite Re-Os Geochronology on Grains from a Quartz Vein with Potassic Alteration Selvage Determined the Age of Mo Mineralization at 297 ± 4.8 Ma. Lithogeochemical Data of Intrusive Units Suggest the Granitoid Rocks Show Calc-Alkaline to High-K Calc-Alkaline, I-Type, and Metaluminous to Slightly Peraluminous Affinities that Formed in a Post-Collisional Setting and Were Likely Sourced from Subduction-Modified Lithosphere. Lithogeochemical Signatures and the Tectonic Environment Classify Zuun Mod into Neither Climax Nor Endako-Types, But as a Mo-Rich Porphyry Cu Deposit

Oxidation States of Fe in Constituent Minerals of a Spinel Lherzolite Xenolith from the Tariat Depression, Mongolia: The Significance of Fe3+ in Olivine

The oxidation states of Fe within olivine, orthopyroxene, clinopyroxene, and spinel in a spinel lherzolite xenolith from the Tariat Depression, Mongolia were investigated using 57Fe Mössbauer spectroscopy to evaluate the redox condition of the upper mantle from which the Tariat spinel lherzolite xenolith was derived. The purity of separated minerals for the Mössbauer spectroscopic analysis was examined using X-ray powder diffraction, Raman spectroscopy, and transmission electron microscopy. Average Fo and Fe contents of olivine at the core part of the xenolith are 89.9(4) mol % and 0.195(3) atoms per formula unit, respectively. The Fe3+/ΣFe values of the olivine, orthopyroxene, clinopyroxene, and spinel, determined by Mössbauer spectroscopic analysis, are 0.027(2), 0.15(1), 0.26(3), and 0.34(5), respectively. The Mössbauer spectrum of olivine consists of two doublets assigned to Fe2+ at the octahedral sites and one doublet, with I.S. of 0.40(2) mm/s and Q.S. of 0.69(3) mm/s assigned to Fe3+ at the octahedral site. Since the Tariat spinel lherzolite xenolith in this study shows no evidence of metasomatism or thermal alteration, the existence of a small amount of Fe3+ in olivine and the fairly high Fe3+ contents of clinopyroxene, orthopyroxene, and spinel imply that the upper mantle under the Tariat area was in a rather oxidized condition