Pressure and temperature (P-T) conditions of syn- and post-mélange formations of the Inui Melange in the Shimanto Belt, Akaishi Mountains, were estimated by fluid inclusion analysis. The Inui mélange is mainly of tectonic origin and was formed along a decollement in a subduction zone in the Late Cretaceous to the earliest Paleogene time. Several stages of vein development during the syn- and post-mélange formations were recognized. Fluid inclusion analyses were carried out on syn-mélange quartz veins and a post-mélange quartz vein, classified based on the cross-cutting relationships with mélange fabrics such as pressure-solution cleavages. The P-T conditions of the syn-mélange veins were in the range of 200 MPa to 320 MPa and 140°C to 240°C, whereas those of the post-mélange vein were in the range of 290 MPa to 350 MPa and 210°C to 290°C. Assuming the water depth between 0 to 6,000 m and total fluid pressure was equal to lithostatic pressure, the geothermal gradient of the syn- and post-mélange formations were estimated to be between 15°C/km and 30°C/km. This geothermal gradient is characteristic of sediment-dominated subduction zones.

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The Hida metamorphic belt is divided into three tectonic units, called western, central and eastern massif, respectively. The Furukawa area is located at the southern part of the western massif and the Miyakawa-Kamioka shear zone develops in the area. The area consists of geissose rocks, trondhjemites and mylonitized trondhjemites, both partly including Inishi syenite, ultra mylonites, mylonites, protomylonites and younger granite. We present the obliquities of 108 K-fedspars from these rocks, which are classified into 8 types from type I of monoclinic to type VIII of triclinic ones.
The K-feldspar obliquities of mylonitized trondhjemites, ultra mylonites and mylonites are characterized by the abundance of type VI to VIII, suggesting that they were formed by mylonitization. Those from protomylonites, located at the western and central northern parts of protomylonite zone, are also characterized by that of type VI to VIII and those from the western body of younger granite by type VIII. The zone of triclinic K-feldspars-rich region might indicate the effect of stronger mylonitization, and is a little narrower than the Miyakawa-Kamioka shear zone. The gneissose rocks also have type VI to VIII, indicating the effect of mylonitization. Therefore, the Furukawa area might be considered to have affected significantly by mylonitization. The K-feldspar obliquities from the younger granite, located at eastern part of the area, consist of types I and VI. The presence of type VI might indicate retrogressive metamorphism after the mylonitization. The K-feldspar obliquities from the shear zone in the area are compared with those from the shear zone in the central and eastern massifs of the Hida metamorphic belt and discussed.

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Two types of taenite lamellae were observed, i.e. the clear and the heterogeneous taenite, in the Widmanstätten structure in Toluca iron meteorite. Cooling rate for Toluca meteorite was determined using the central Ni content method, for both types of taenite. The Ni concentration within heterogeneous region (plessite) in taenite was approximated to fit the M-shaped distribution shown by the rim and parts of the central portions. The clear taenite lamellae and the heterogeneous taenite yield similar cooling rates of 100–200°C/Ma. Based on this result, it is supposed that the heterogeneous taenite has been originally homogeneous in composition. As the temperature drops below 400°C (kamacite nucleation closure temperature), the interior of wider taenite transform into plessite. Textural observations indicate that the harp-like taenite structure is always associated with schreibersite (phosphide). The presence of P in Fe-Ni alloy has a pronounced effect on Ni diffusion and the formation of the Widmanstätten structure. The harp-like taenite may have been formed in high-P concentration regions in Fe-Ni alloy.

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In order to investigate the mechanism of the Asian Monsoon system and to improve the accuracy for the prediction of the global climate, it is important to study water vapor change in the atmosphere of the Monsoon region. We can estimate precipitable water vapor (PWV) from GPS data with higher time resolution than that obtained by other instruments.
We performed GPS measurements at 4 stations in Thailand during the period between 1998 and 2001 and investigated their PWV changes. GPS observation at Khon Kaen in the northeastern Thailand started in 2001. The new data at Khon Kaen were processed to obtain the PWV in order to understand the characteristics of its seasonal and diurnal changes.
The results show that the obtained PWV periodically changes widely in the range of 20 mm to 60 mm, with 1 or 2 weeks duration in the dry season, and we can note that the PWV increases before rainfall and decreases after rainfall. On the other hand, it is almost constant at about 60 mm or 70 mm without any changes even when it rains in the wet season. In the monsoon break of the middle of July 2002, the PWV obtained decreased by about 10 mm.
We compared the PWV obtained with that of NCEP/NCAR reanalysis data, and the results show that our data are usually larger by about 10 mm than NCEP/NCAR data.
The PWV diurnal changes for pre-monsoon and monsoon periods were also discussed. The difference of diurnal changes of the two periods was small and they showed that PWV had the minimum value at 4–7 o’clock in the morning, it increased in the afternoon and it had the maximum value in the evening or the midnight irrespective of the season.

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Sampling records of threatened marine mollusks in Suruga Bay, central Japan were compiled based on the private collection of Tohru Terada, who had collected molluscan shells by beachcombing and caught along with fisheries during November 1975 to March 2000. In this study, a total of 109 species were selected from the red-data marine shells in Sagami Bay, a similar gulf adjacent to Suruga Bay, in order to trace their sampling records. Most of the red-data species living in intertidal or subtidal to 10 m in bathymetrical depth have rarely been recorded in Suruga Bay after 1980’s as is the case with Sagami Bay, whereas many species living in deeper zones (-20 m or 50 m) were often found as alive individuals in 1990’s. These facts suggest that pollution, reclamation and shoreline protection works have deteriorated the intertidal and subtidal environments of Suruga Bay so that the marine benthic fauna have been severely damaged around there. The environmental changes in Suruga Bay may be critical for the species living in embaymental and tidal land habitats in branch bays, however the severity of the threat of these species cannot be assessed because of data deficiency. Monitoring these species is required for complementing the red data on Suruga Bay.

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A three-dimensional digitizing system for measurements of organic forms was installed in the Institute of Geosciences, Shizuoka University. It is based on a triangulation method using an image-capture device that enables multiple viewing of the object fixed on the stage. The device consists of a standing arm and an attached CCD camera that can be tilted so as to capture images from a known angle of offset. The CCD camera and its controller can be connected with a personal computer via USB. Measurements of x and y coordinates of points of interest are made on the captured image using a computer program developed in this study. The x and y coordinate data collected from the images of normal and offset views determine the z heights of the points. An original add-in program for Microsoft Excel is used to calculate the z values of the points. The program corrects the warp caused by aberrations of the lens simultaneously with calculation of z. It also includes the option for calculating three-dimensional Bookstein shape coordinates based on the calibrated data. The result obtained from 20 repeated measurements of a sample indicates that the standard deviation of the measurements is less than 1% of the mean in the x-y plane and no more than 2% in z dimension. The system is most useful for capturing landmark-point and line-tracing coordinate data from a small- to medium-sized specimen.

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This study describes the optimum experimental conditions required for the conversion of oxygen to carbon dioxide produced in the laser ablation oxygen extraction system (Matsui et al., 2003). Purity of carbon used in the converter, duration of preheating between sample conversions (1 hour at ~630°C) and careful temperature control during conversion (600°C) can yield high reproducibility. Experimental runs with oxygen gas from cylinder gave a reproducibility for δ¹⁸O values of ± 0.1‰ (n = 4).

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