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K-Ar ages of .. Ma (Kamihara Tonalite), . . Ma (Mitsuhashi Granodiorite), .. Ma (Inagawa Granite, massive facies), .. Ma (Inagawa Granite, gneissose porphyritic facies) and .. Ma (Busetsu Granite) were determined from the Ryoke plutonic rocks in the Asuke area, central Japan. All of these ages are interpreted to be cooling ages related to the blocking temperature of biotite. The coincident -Ma cooling ages of the Kamihara Tonalite, Mitsuhashi Granodiorite, massive facies of Inagawa Granite and Busetsu Granite in -Ma suggests that these plutonic rocks followed a common cooling path in this area after solidification of the Busetsu Granite (ca. -Ma). On the other hand, solidification age of the gneissose porphyritic facies of Inagwa Granite is ca. -Ma, and K-Ar age of .. Ma from the gneissose porphyritic facies of Inagawa Granite was younger than other plutonic rocks in the Asuke area. thus, the K-Ar age is concordantly interpreted as cooling age of the granite.

( 2015 ) Multiple trace element analyses for silicate minerals and glasses by laser ablation-inductively coupled plasma-mass spectrometry ( LA-ICP-MS ) . Bull. Geol. Surv. Japan, vol. 66 ( 9/10 ) , 6 figures, 6 tables.Abstract: Programs were established in the shared research facilities of the Geological Survey of Japan ( GSJ-Lab ) for trace element analysis of silicate minerals and glasses in microspots using laser ablationinductively coupled plasma-mass spectrometry ( LA-ICP-MS ) . National Institute of Standards and Technology ( NIST ) synthetic glasses reference materials ( NIST 613 and NIST 611 ) were used as external calibration standards, and suitable instrumental operation settings were set as follows; 0.5 L min -1 He carrier gas flow rate, 100 μm laser spot diameter, 5 Hz repetition rate, and 40 % laser energy ( fluence ca. 2.0 J cm -2 ) . NIST 615 and NIST 613 were analyzed as unknown samples to evaluate precision and accuracy. Precision was mostly less than 30 % for 45 elements from 45 Sc to 238 U for laser spot diameters ranging from 100 to 10 μm. Accuracy was evaluated according to the difference ( DIF ) between the analytical results and reference values in the literature. Accuracy for the analysis of NIST 613 was DIF < 30 %, except for Sc, Mn, Ni, and Ge. For NIST 615, DIF was less than 30 %, except for Tl with laser spot diameters of 20 and 10 μm, and for Cd with a laser spot diameter of 20 μm. The depths of laser pits for generic conditions for the analysis of clinopyroxene, amphiboles and plagioclase were estimated as extents without penetration of the thin section samples. Two suites of analytical programs ( 34 and 27 elements ) were additionally prepared for general purpose petrological and geochemical discussion and the accuracy of both was evaluated. The DIFs for the suite of 34 elements were mostly less than 30 %, although some for Cr, Mn, Ni, and Cs with laser spot diameters < 40 μm exceeded 30 %. In the suite of 27 elements, the DIFs were < 30 %, except for Sc.

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The nanocrystalline Ni W alloy fabricated by an electrodeposition method has a high strength and high bending ductility. However, its fatigue properties are not known yet. Therefore, fatigue tests were carried out to clarify the fatigue properties. Nanocrystalline Ni W alloy specimens containing 16.9 at W with about 20 mm in thickness, 200 mm in parallel part length, and 100 mm in width were produced by both UV photolithography and electrodeposition methods. The average grain size was about 6 nm in diameter and the tensile strength was about 2.8 GPa. The fatigue test was conducted at a stress ratio of 0.1 and a frequency of 10 Hz. The fatigue limit and fatigue ratio showed 2.1 GPa and 0.74, respectively. Macroscopic fractured morphology showed no necking and perpendicular fracture for the loading axis. However, microscopic fracture surface showed flat and featureless morphology at near the crack initiation region and it showed striations from the region where the striation spacing became more than about 10 nm. The final unstable fracture surface showed dimples with a diameter of 100～200 nm.