This paper is concerned with the distribution of manganese and the growth process of the manganese micro-particle in the Suruga Bay. The results obtained are as follows; (1) The manganese contents in the sea water are 2-4μg Mn/l, 4-17μg Mn/l and 1-4μg Mn/l in the surface, intermediate and deep layer respectively. (2) Three major classifications of the microparticle seem to be possible, namely, needle like micro-particle (10-30μ), sea urchin like microparticle (20-400μ) and granular micro-particle (10-1000μ). (3) The intimate relation seems to be exist between the dissolved oxygen and the content of manganese. The former decreases sharply in the intermediate layer where the latter increases evidently. This fact indicates the geochemical condition necessary for the genesis of manganese micro-particle.

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The geology and micro-paleontology of the Tsukayama District in Santo-gun, Niigata Prefecture, known as the " Hachikoku oil-field," have been studied by the present writer. The geological map and stratigraphical classification of the Tertiary and the Pleistocene rock along Tsukanoyama〜Suganuma route in this district are shown in table 1 and figure 1. The columnar section, composition of the diatom assemblage of each horizon, change of sedimentary environments assumed from the former is shown in figure 2. From these works, The followings are concluded: 1) On the basis of the present stratigraphical survey the B Formation (≒Nishiyama Formation) composed of silt〜mudstone seems to be the deposit in the sublittoral zone, influenced by the fresh water. This formation is also distinguished from the underlying ones by the presence of some extinct species (Denticula hustedtii, Fragllariopsis pliocena, Thalassiosira cfr. nativa and T. zabelinae etc.). 2) The C Formation (≒Haizume Formation), divided into C1 and C2, is supposed to be the brackish water deposits of the inner bay, although the diatom valves are so rich. The lower part (C1) consists of sandy siltstone, and the upper part (C2) of fine〜medium sandstone. 3) The D Formation mainly composed of wellsorted fine sandstone bluish gray in colour may correspond to the lowest part of the Uonuma group of Pleistocene. The diatom assemblage is represented by the dominance of fresh water species, slightly accompanied by the brackish water ones. 4) The E Formation corresponding to the lower part of the Uonuma group is composed of the irregular alternation of sandstone, conglomerate and siltstone deposited in fresh water basin. In this route the middle and the upper parts of the E Formation are not recognized.

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The object of this study is to present that in what way concentration and constituent of amino acids in sediments are influenced by sedimentary environment and duration of diagenesis. 50 samples were collected from the Cenozoic sediments distributed in the Osaka area, Boso Peninsula, the Niigata area and the Jyoban area. The analytical results on these samples are summarized as follows. 1. The concentrations of amino acids in 50 samples of the Cenozoic sediments show a decreasing trend with increasing duration of burial. The values ranged 900-1800μg/g in the Holocene sediments, 20-520μg/g in the Pleistocene sediments, 3-35μg/g in the Pliocene sediments and 4-15μg/g in the Miocene sediments. From two samples of the Oligocene sediments, no amino acids were detected (Table 1, Fig. 5). Furthermore, analytical results of the core samples from the borings at Osaka show that the amino acid concentrations at the Holocene and the Pleistocene sediments decrease exponentially with increasing depth of burial (520-20μg/g), but below the depth at the Pliocene-Pleistocene boundary the sediments have a uniform concentration level of amino acids (10-20μg/g). 2. Clayey sediments have high concentration level of amino acids compared with silty and sandy sediments. This fact may be caused by low microbial activity in reducing environment. 3. 19 kinds of amino acids are identified from 40 samples of the Cenozoic sediments (Table 2). 17 kinds of amino acids among them are a-amino acids, and the other two are γ-amino butyric acid and β-alanine. 16 kinds of amino acids-leucine, valine, γ-amino butyric acid, glycine, alanine, threonine, serine. proline, tyrosine, β-alanine, glutamic acid, aspartic acid, arginine, histidine, lysine, and ornithine-are detected from the almost all of the samples examined. Proline and hydroxyproline are detected from about half of the samples. Cystine is detected from a few of the samples. 4. Throughout all of the samples, there are no significant changes on the amino acids spectra (Table 2). This fact shows that the above mentioned 19 kinds of amino acids decrease at the definite rate independent of each own decomposition rate in a free state. This phenomenon suggests that amino acids in sediments are incorporated in nonproteinaceus polymers so called humin or kerogen. 5. γ-amino butyric acid and β-alanine are not diagenetic products from α-amino acids, but may be biogenetic matter produced by micro-organisms in the early stage of cliagenesis. 6. It is suggested that amino sugars may also be widely disseminated in the Cenozoic sediments of Japan.

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北海道の中央高地にある十勝岳(海抜2,077 m)は,安政4年(1857年),明治20年(1887年)ごろ,大正15〜昭和3年(1926〜1928年)および昭和37年(1962年)の4回の噴火記録がある.北海道中央部の歴史は僅か1世紀余を遡るにすぎないが,十勝岳では,これ以前の比較的新しい時代に溶岩やスコリア流などの流出が知られている.(渡瀬, 1962;勝井ら. 1963; TAKAHASHI, 1965)一方,十勝岳東南方には,層厚変化からみて恐らく十勝岳に起源をもつ降下火山灰が分布している.山田(1958)は火山灰層の上位に発達する泥炭層の厚さから,これらをTo-b層:200年前,およびTo-c層:700〜800年前と推定している(1955年を基準とした年代).我々は,十勝岳の最近における活動史を知るため,同火山北西斜面のスコリア流堆積物中および溶岩流の直下から炭化木片を採集し,その^<14>C年代決定を学習院大学木越邦彦教授にお願いした.

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1971年11月11日,川崎市生田緑地内で行なわれたローム丘陵地崩壊実験では,予期しない15人の犠牲者をだす事故となった.これについては一般ジャーナリズムは別としても,"そくほう"234号,"国土と教育"11号で詳細に紹介・報告された.これらに対して若干屋上屋を架する感じはするが,地質の面について多少の資料と観点を補う意味でのべておきたい.本稿は主として事故直後の観察によるもので,観察・資料の面で制約があり,細部の点で正確を期しがたかった面はあるが,現在,総理府委嘱の調査委員会によって調査が進められているので,それが公表された段階においてより明らかにされるであろう.

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