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広島県東広島市の七ツ池では，排水時の池底で赤色風化した堆積物を観察できる。この池底堆積物の柱状試料を4 本採取し，各柱状試料について層相，pH，酸化還元電位測定，色彩測定，及び赤色部の詳細観察を行った。その結果，（1）風化層の多くは，砂層の上位に位置し，地下水面の変動帯に位置していること，（2）赤色化メカニズムのモデルについては，砂層の間隙水中での拡散供給のプロセスが適用できたが，無機的な酸化還元反応だけではなく，硫酸還元菌や鉄酸化細菌などの微生物の関与を考慮する必要があること，（3）色彩データのうち，彩度が化学的風化（鉄酸化物生成）の進行状況の指標として有用性があることが明らかとなった。また，これらの結果に基づいて七ツ池の堆積物の地学の学習素材としての可能性を考察した。, During drainage, reddish weathered sediments can be observed at the bottom of Nanatsu-ike Pond in Higashihiroshima City, Hiroshima Prefecture. Four columnar samples of this reservoir-bottom sediment were collected. Each columnar sample was subjected to facies, pH, redox potential measurement, color measurement, and detailed observation of the red part. The results showed the following: (1) most weathered layers were located above the sand layer and in the zone of groundwater-surface fluctuation; (2) for the model of the reddening mechanism, the process of diffusion-supply in the pore water of the sand layer could be applied, but it was necessary to consider the involvement of microorganisms such as sulfate-reducing bacteria and iron-oxidizing bacteria in addition to the inorganic redox reaction; and (3) among the color data, chroma was found to be a useful indicator of the progress of chemical weathering (iron oxide formation). Based on these results, the potential of the Nanatsu-ike Pond sediments for geoscience educational materials is discussed.

A shallow submarine hydrothermal system at 22 m depth in Tachibana Bay, Nagasaki, Japan was studied. Submarine hot springwaters and sediments of the vent sites were collected for analyses of chemical composition. Temperature of the submarine hot springwater at the vents was measured at 70～80oC, and clear decreases in pH and salinity were observed in relation to surrounding seawater. Si(OH)4, NH4+ and Mn were enriched in the submarine hot springwater, but Fe was relatively low compared with the onshore hot springwater near the coast. Black-color sediments with high concentrations of Fe, S, Sb and As indicate the preferential removal of Fe relative to Mn during transportation of the hot springwater under the seafloor. Supply of inorganic nutrients such as NH4+ from the vents may stimulate phytoplankton production near the shallow submarine hydrothermal system during the stratified summer.

Distribution of hydrothermal activities and chemical composition of surrounding sediments wereinvestigated for shallow submarine hydrothermal systems in Tachibana Bay, Nagasaki, Japan as a firststep to elucidate its possible influences to the coastal ecosystem. Based on the observations of fumarolicgas emissions using quantitative echosounder, existence of hydrothermal activities was confirmed at 33-34 m depth near the coast of Obama hot springs. These were many small (2-6 mm in diameter) holes onthe surface of the bottom sediment, and the area of the fumarolic gas emissions had a horizontal scaleof 6-63 m. Hot (78℃) and dark subsurface-sediment at the hydrothermal activity region showed unusualelemental composition characterized by higher contents of Al, S and As, and lower amounts of Ca, Cl andBr compared with that of the typical coastal sediment.

鹿児島湾水深218mの海底堆積物から分離された放線菌のケラチナーゼ生産の培養条件を検討し、さらに培養液から本酵素を単離・精製して諸性状を明らかにした。高い酵素活性は1/4強度(25%,v/v)の人工海水濃度で見られた。培養液上清からイオン交換及びゲル濾過クロマトグラフィーによりケラチナーゼを精製して分子量が約3万で、熱及びpH安定性の高いことを確認した。また,本粗酵素はカイメン,マダイのウロコ,羽毛および羊毛などの難分解性ケラチンを原型を留めないほど分解したが、アオウミガメの甲羅およびミンククジラのヒゲなどの難分解性ケラチンはほとんど分解しなかった。, Cultivation conditions for keratinase production by an actinomycete strain isolated from deep-sea sediments of Kagoshima Bay at a depth of 218 m were investigated and character ized. Maximum production of the enzyme was obtained in a quarter strength artificial seawater. Purified enzyme obtained from the culture supernatant of the strain using cation exchange chromatography and gel filtration showed an approximate molecular weight of 30,000D with thermostable and pH stable characteristics.Various native keratins such as sea sponge, scales of red seabream, feather and sheep wool were completely decomposed by the partially purified enzyme, whereas shell of green turtle and barbell of minke whale were hardly decomposed.

2006年5月から2008年11月にかけて風蓮湖とその流入河川の水質および堆積物の性状を調査した.風蓮湖における河川水と海水の混合形態は潮汐によって変化し,下げ潮時にはエスチュアリー循環の弱混合型であり,上げ潮時は強混合型である.酪農の影響をうけた高濃度の栄養塩は風蓮湖に流れ込み,河口域でほぼ植物プランクトンにより消費されることが示された.2007年4月〜2008年3月までのデータを一年として,平均流量を用いた主要3河川による,風蓮湖への年間負荷量はDINで529t, DIPで58tと計算された.さらに,負荷された栄養塩を利用した植物プランクトンの推定基礎生産量は2,533〜4,550t Cとなり,負荷された栄養塩のうち,DINで54〜98%,DIPは河川のものだけで考えるとほぼ100%消費されていることが分かった.湖内に分布するPOCは,河川由来のものよりも湖内で生産されたものの方が,割合が大きかった.また,湖内で生産された粒子は,容易に湖外に流出しない傾向にあった。また,堆積物表層のシルト含有率は,湖奥部中央〜最奥部にかけて高くなっていることから,水柱の粒子が湖奥部に選択的に堆積している可能性が示された., We investigated the quality of water of the inflow river in Lake Furen from May, 2006 through November, 2008. The mixed form of river water and the seawater in Lake Furen changed by ebb and flood tides and was weak mixed type of the estuary circulation at the time of the ebb tide and was strong mixed type at the time of the high tide. Highly concentrated nutrients from dairy farming drainage flowed into Lake Furen, and we examined the amount of nutrients used by phytoplankton in the estuary. We calculated the data from April, 2007 to March, 2008, which was 529 ton in DIN and 58 ton in DIP when we estimated load quantity in the year to Lake Furen by 3 main rivers, using the mean flow quantity as a minute for one year. Furthermore, this value became 2,533〜4,550 ton C when the amount of phytoplankton primary production using inputted nutrients was assumed to be 54-98% in DIN case, and approximately 100% in DIP case when we assumed only inputted nutrients from the river. In addition, the particles produced in the lake tended to not flow easily outside the lake. In addition, we estimated the silt content of, the sediment outer layer at various depths, and we revealed that the particles of the water column were selectively deposited as the silt became higher at inner part of the lake.

海水中の懸濁物と，海藻の葉上堆積物は，ともに藻体表面に到達する光を質的かつ量的に変化させ，海藻の生産力に多大な影響を及ぼす。本研究では内湾域である広島湾における大型褐藻クロメの葉上堆積物とクロメ群落直近の海水中の懸濁物について，両者の光吸収係数を統一的手法（QFT法）に基づいて把握し，その特性を比較した。懸濁物と堆積物の全体の光吸収特性に明瞭な差は認められず，葉上堆積物の多くが沈降した懸濁物によって構成されていたことが推察された。懸濁物・堆積物ともに，デトリタスや微細藻類など多様な要素により構成されており，光合成有効波長域（400-700nm）のうち，短波長側の光は微細藻類の色素以外のデトリタスなどが，長波長側の光は微細藻類の光合成色素が吸収し，それぞれクロメの光吸収に大きく影響すると考えられた。, Light is the primary limiting factor for macroalgal production. Understanding not only the quantity but also the quality of light reaching algal thalli is important to the success of algal recovery and sustainability. This study explores the optical properties of accumulated matter on the thalli of Ecklonia kurome and suspended matter in the water surrounding an Ecklonia bed in Hiroshima Bay, based on spectral absorption coefficient estimated by the quantitative filter technique (QFT) method. According to the experiments, minimal difference of optical properties between suspended matter and accumulated matter was recognized. It is assumed that suspended matter in the water formed the accumulated matter on the thalli of E. kurome. Both suspended matter and accumulated matter were composed of multiple components, various kinds of microalgae, detritus and inorganic matter. In the wavelength-specific photosynthetically active radiation (400-700nm), detritus and inorganic matter formed the primary absorber of blue light, while microalgal pigments was the primary absorber of red light. Each absorber in suspended and accumulated matter might attenuate specific wavelength and change the quality of light reaching the thalli of E. kurome.

ひと生活圏内にある小規模な池で採取した水及び堆積物試料を環境教育に活用するための基礎資料を得るため, 上越教育大学構内の弁天池を対象として, 水温, pH, 導電率, 溶存酸素濃度, 硬度, アルカリ度及び化学的酸素要求量を測定した｡溶存酸素濃度, 化学的酸素要求量, アルカリ度と水温は明確な季節変動を示した｡これらの項目で弁天池の基本的な水質変動挙動を概ね理解することができた｡弁天池においては外部からの有機物の流入の影響は大きくなく, 化学的酸素要求量の季節変動は水中の生物活動と関連すると考えられた｡また底質分析も行い, マンガン, 秩, 鉛, 鍋, 亜鉛について含有率を測定した｡, To utilize the reservoir in education, water and sediment samples of a reservoir were chemically analyzed. In Benten pond of Joetsu university of education yard, temperature, pH, conductivity, dissolved oxygen, hardness, alkalinity and chemical oxygen demand (COD), were measured. The seasonal variations of water have been clarified.DO, COD and alkalinity and the water temperature showed clear seasonal variation. The sediment analysis provided concentrations of manganese, iron, lead, copper and zinc.

The infrared stimulated luminescence (IRSL) dating was performed for the sedimentary samples from the Neolithic sites, Zaisanovka 1 site, Posiet 1 site and Ustinovka 3 site, in the Russian Far East (the Maritime Region). The IRSL samples were collected from the 3 and 4 layers at the Zaisanovka 1 site, the upper and lower layers of the cultural horizon at the Posiet l site and the III and IV layers at the Ustinovka 3 site. The paleodose of each sample was estimated by the multiple aliquot additive dose (MAAD) protocol with poly-mineral fine grain samples prepared from the collected sedimentary samples. The IRSL measurement conditions (detection wave lengths, measurement temperatures and preheat conditions) were determined according to the results of preliminary experiments using four types of standard feldspar specimen. Annual doses (dose rates) were estimated from the concentrations of U, Th and K-40 using a high-purity Ge gamma-ray spectrometer. The IRSL ages obtained are 1.9±0.8ka and 3.4±0.7ka for the Zaisanovka 1 site, 8.7±2.1ka, 14.9±2.5ka for the Posiet 1 site and 8.3±1.3ka, 11.0±0.8ka for the Ustinovka 3 site. The comparison of the IRSL ages with known C-14 data are also discussed.

学位記番号：工博甲480

Although the author conducts investigations and research of deposits during the geological age, in parallel he continues the survey on magnetic susceptibility of deposits of the Recent epoch. The report shows the results of measurements of magnetic susceptibility of deposits on the coast around Tateyama Bay. We found that the composition and again size of the coastal deposits of the Recent epoch distri- buted in the South of the Tateyama Bay area of the Boso Peninsula show signs of magnetic susceptibility. But the magnetic susceptibility of the sandy beach and that of the rocky beach differ. It was also confirmed that the portable Magnetic Susceptibility Meter with it's simple operation enables us not only to identify rocks and alluvial rocks, but also to examine accumulation conditions of the coastal deposits of the Recent epoch.

Spherules isolated from deep sea sediments were analyzed for chemical compositions. Three types of internal texture are observed in Ni-bearing I-type spherules: Ni free Fe oxide mantle with Fe-Ni metallic core, Fe-Ni oxide mantle with Fe-Ni metallic core and Fe-Ni oxide spherules without metallic core. Numerical simulation was performed in order to estimate variation of temperatures and radii of I-type spherules, and the force of inertia exerted on them entering the atmosphere. From the result of the simulation, it is figured out that spherules lose more than 90 percent of their original mass by ablation over 1,900 C and that the force of inertia is maximum at last stage of evaporation. Based on the observations of I-type spherules and the numerical simulation of their formation, we propose a model of the formation process of I-type spherules: during ablation, metallic core is off-centered, then surface of the core is exposed to the air due to the strong force of inertia and oxidation reaction might proceed from the exposed core surface., 資料番号: AA0063352045

研究科: 千葉大学大学院理学研究科, 修了年:2011年, 学位:千大院理博甲第理37号

東北大学による東日本大震災3ヶ月後緊急報告会 (2011/06/10@仙台国際センター)セッション1「津波による被災の実態とメカニズム」