The inner wall of the Tsukioka hot spring well was covered with green microbial mats which contained black crude oil. The hot spring is located in Tsukioka, Niigata, Japan. The hot spring water (pH 7.3, Eh -184 mV and 49.2℃) that was produced from a 280m in depth originated from fossil seawater. The aim of this study was to investigate of covellite biomineralization in the green microbial mats with crude oil from the Tsukioka hot spring water. Observations by optical and electron microscopy, phospholipid analysis and bacterial cultivation showed that the biomineralization of covellite (CuS) was found on the surface of crude oil droplets. ED-XRF analysis showed that the crude oil contained SO3 (67.6wt%), CaO (24.8wt%) and Cu2O (2.6wt%). Observations by optical and epifluorescence microscopy as well as scanning electron microscopy (SEM) showed that two morphological types of bacteria (i.e., filamentous and coccus typed bacteria) were found on crude oil droplets. Transmission electron microscopic (TEM) observations further revealed that the cell wall of the filamentous bacteria had a double membrane and was surrounded by Extracellular Polymeric Substance (EPS), which might provide the favorable nucleation sites for CuS. X-ray diffraction and electron diffraction analyses of the microbial mats showed that the materials precipitated on the surface of the oil droplets were highly crystallized covellite (CuS). FT-IR spectra of the microbial mats that contained covellite showed the appearance of C-N-H, P=O, P-O-C and N-H bands, indicating the presence of phospholipids (lecithin and phosphoric ester) in the microbial mats. Cultivation experiments, furthermore, demonstrated that the cultivated bacteria were identified as sulfate reducing bacteria (for coccus typed bacteria) and oil decomposing bacteria (for filamentous bacteria). A schematic formation model is here suggested to better understand the interaction between bacterial cells and oil droplets under anaerobic conditions in the Tsukioka hot spring water. The biomineralization of covellite described in this study might have profound implications for bioremediation of oilcontaminated site.

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Curt Adolph Netto (German: 1847-1909) came to Japan in 1873 and stayed until 1886 as "Toreign Employee". He worked at the Kosaka Mine as the chief mining geologist and metallurgist for the first four years and then appointed to the first professor of the Mining and Metallurgy of the University of Tokyo. The author found from the application record written in January 1873 by Takato Oshima which submitted to Tomomi Iwakura ambassador plenipotentiary that Oshima invited Netto. Azuma (1974) estimated that Netto went to the Kosaka Mine in November 1873 from Yokohama through Hakodate, Noshiro, and Yoneshiro River by boat. The author thinks Netto went from Yokohama to Kamaishi by boat and then on foot along Morioka through the Tsugaru Road to the Kosaka Mine, based on Netto's fine sketches and geography. One of Netto's "Japanische Kuste Dat. 7. Nov. 73 "was drawn the Kamaishi Bay from the boat. The mining data including the sketches of Netto should be kept systematically as the historical science data in the Early Meiji stages without photograph record, and should be investigated in detail by specialists.

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The SK110 Tephra Bed is prominent subaqueous volcaniclastic gravity flow deposit in the Niigata region and was correlated to the on-land Omine welded Tuff Bed in the Nagano region. The Omine-SK110 tephra flowed down as a pyroclastic flow, and entered into water in the Niigata region, differentiated into bipartite subaqueous gravity flows (division A and division B). In the division A of the SK110 in the Niigata region, which represents a high-density gravity flow, the grading is very weak and the thickness (about 60cm) and grain size (Mdφ=2.0〜2.8φ) is almost constant along the supposed flow axis. In the division B, which represents a low-density gravity flow, the thickness is almost constant (about 30cm), while the grain-size changes slightly finer (Mdφ=3.45〜4.65φ) to the downflow. Farther, the SK110 Tephra Bed was correlated to the Km3 Tephra Bed in the Oga Peninsula, Akita Prefecture, about 450km apart from the source volcanic area. The tephra sequences of the SK110 and Km3 are very similar, implying the possibility of the identical of the subaqueous bipartite gravity flow deposit. The lateral changes of the thickness and grain size are concordant through the Niigata to Akita regions. Moreover, it is also possible to assume the downslope (trough depression) from the Niigata region toward the Akita region, along the eastern margin of the Japan Sea at about 1.6Ma.

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The origin of jetted sand caused by liquefaction due to two earthquakes in Miyagi Prefecture in 2003 was studied by grain size and sand fraction analysis. Core sediment samples were obtained by drilling and Geoslicer in the Ushiami and Hamaichi areas of Naruse, Miyagi Prefecture, where were seriously affected by liquefaction. The core samples consisted of four sediments: (1) surface jetted sand, (2) the original surface soil, (3) coarse artificial back-filled sand, known locally as "Yamazuna" sand, and (4) ancient beach-sand, in descending order. Grain-size analysis showed that, grain-size parameters of jetted sand in the Ushiami area were similar to those of the uppermost part of the ancient beach sand layer. In the Hamaichi area, grain-size characteristics of the jetted sand was similar to both the "Yamazuna sand" layer and the beach sand layer, but sand fraction modal compositions of the jetted sand corresponded to those of the beach sands. These results indicate that the Naruse jetted sands originated from the ancient beach-sand layer, which had previously been considered to be resistant to liquefaction arising from earthquakes.

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Fission track dating was carried out on tuffaceous samples collected probably from the lower part of Miocene sequence in the northern part of the Chichibu sedimentary basin, northeast Kanto Mountains. The aim of the dating was to determine the age of the beginning of the Miocene transgression which caused the deposition of voluminous clastic sediments in the Chichibu basin. Zircon FT ages were obtained from the Nenokami Formation and the Shirasu Sandatone Member of the Ushikubi Formation. The ages were 16.0±0.7Ma and 16.7±1.1Ma, respectively. These ages were determined using a standard statistical approach to eliminate old detrital zircon crystals from the age population. The FT results are consistent with stratigraphic order, and suggest that the depositional system probably was developed at the end of the lower Miocene at least.

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