巻号一覧
32 巻 (1978)
- 6 号 p. 267-
- 5 号 p. 225-
- 4 号 p. 175-
- 3 号 p. 113-
- 2 号 p. 51-
- 1 号 p. 1-
32 巻, 2 号
選択された号の論文の12件中1～12を表示しています
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鈴木 郁夫原稿種別: 本文
1978 年 32 巻 2 号 p. ii-iia
発行日: 1978/03/25
公開日: 2017/07/26
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岩田 圭示原稿種別: 本文
1978 年 32 巻 2 号 p. 51-57
発行日: 1978/03/25
公開日: 2017/07/26
ジャーナル オープンアクセスThe author studied calcification process and architectural shell structure of the protoconch of an archaeogastropod, Haliotis discus hannai INO, which is commonly cultivated in our country. By means of optical and electron microscope, following results were obtained. During early veliger stage, "organic covering membrane" and "organic spherules" (new terms) are secreted by shell gland. The former is a thin membrane covering soft body, and the latter is small round organic material deposited innerside of the covering membrane. Crystal nuclei of lessÅ than 100Å in size heterogeneously appear within "organic spherules". The electron diffraction study of these particles within organic spherules does not show to be crystals with certainty until they grow into 200Å in size. These particles grow into flaky or granular aragonite crystallites of less than 0.1μ in size. As calcification proceeds, horizontal view of crystallite aggregations depositing within organic spherules show clearly spherulitic pattern. Adjoining crystallite aggregations make fully calcified thin layer. Electron and X-ray diffraction studies show that all of these crystallites are aragonite, and electron probe microanalysis does not reveal existence of phosphate. Accumulation of granular aragonite crystallites does not show preferred orientation and ordered blocks. For such type of structure, a new term "homogeneously granular protoconch architectural structure" is proposed. Under this layer, which is secreted by shell gland, another shell layer is formed by mantle epithelial cells. This shell layer is constructed by intersecting blocks of aragonite lamellae with opposing direction, which run obliquely against the shell surface. Another new term "crossed block architectural structure" is proposed for convenience. Micro-twin pattern found within these aragonite crystals is very similar to those of crossed-lamellae.抄録全体を表示PDF形式でダウンロード (5758K) -
田崎 和江原稿種別: 本文
1978 年 32 巻 2 号 p. 58-62d
発行日: 1978/03/25
公開日: 2017/07/26
ジャーナル オープンアクセスThe surface of fresh plagioclase usually shows smooth plane and has a weaving texture which suggests cryptic unmixing at vertical section (plate I-1). At the incipient stage of weathering, various features caused by chemical erosion appear on the plagioclase such as etch pits (plate II-5), conical hollows and square holes (plate I-4). Amorphous thin layer of which thickness is less than 0.5μm occurs successively or simultaneously on the surface (plate I-3). Occurrence of the thin layer suggests transitional state from frame work sillicate to clay minerals. The knobby substance, aggregate of fine and rounded spherules which is morphologically identified as spheroidal allophane occurs subsequently in the thin layer (plate II-7, 8). In the next stage of weathering, the following changes are observed; 1) Formation of imogolite (plate III-9) and gibbsite (plate III-10). 2) Formation of halloysite (plate III-11, 12). Imogolite occurs first as tiny bumps from the edges of the amorphous thin layer. Coexistence of gibbsite and imogolite is common in the same grain of weathered plagioclase. Gibbsite crystal shows short prismatic or tabular form (plate III-10 right upper). Observation of glassy matrix in the volcanic ash indicates that weathering should advance more easily in glassy material than in coexisting plagioclase (plate IV)抄録全体を表示PDF形式でダウンロード (4731K) -
鎌田 耕太郎原稿種別: 本文
1978 年 32 巻 2 号 p. 63-67
発行日: 1978/03/25
公開日: 2017/07/26
ジャーナル オープンアクセスMutual relationship between the intensity of radioactivity (γ ray) and rocks belonging to the Mesozoic and Upper Permian formations developed in the Karakuwa Peninsula, Kitakami Mountains was studied in detail. As a result, it became evident that the higher the intensity in general the higher the stratigraphic level of the sequence of Mesozoic and the Upper Permian formations. Furthermore, within the same formation, rocks of slaty facies show almost always high intensity than sandy and conglomeratic facies. Especially, there is a horizon showing the highest intensity in the upper Kogoshio formation (Upper Jurassic), which is a good key horizon since it is widely traceable in the surveyed area. Dykes, mostly of porphyrite, and sometimes of granodioritic rock, intruded into the Palaeozoic and Mesozoic formations, are definitely low in intensity, compared with the above mentioned country rocks.抄録全体を表示PDF形式でダウンロード (549K) -
小室 裕明原稿種別: 本文
1978 年 32 巻 2 号 p. 68-82a
発行日: 1978/03/25
公開日: 2017/07/26
ジャーナル オープンアクセスThe middle to the upper Miocene series in the Yanaizu region is divided into five formations, namaly the Ogino, the Urushikubo, the Shiotsubo, the Sunagohara, and the Fujitoge formations in ascending order, all of which are in conformable relation except that the unconformities at the base of the Sunagohara formation and partly at that of the Fujitoge formation. The Urushikubo formation may unconformably overlie the Ogino formation in part. The Ogino formation and the lower part of the Urushikubo formation consist of pyroclastic rocks. The upper part of the Urushikubo formation, the Shiotsubo formation, and the lower part of the Fujitoge formation consist of shale, sandstone, and siltstone respectively. The Sunagohara formation and the upper part of the Fujitoge formation consist of pyroclastic rocks. Basaltic, dacitic, and rhyolitic dykes intrude into the Urushikubo and the Shiotsubo formations. The fundamental geologic structure is nearly flat, except for some flexure, synclines and anticlines which have N-S trending axes. The horizontally bedded Sunagohara formation is distributed in a restricted area, about 5 km in diameter, and abuts on the steedly dipping surface of the unconformity at the margin of the basin. Basal conglomerate, which is very poorly sorted and angular talus-like breccia including boulder gravel with 3m in maximum diameter, is distributed along the margin. It would be deposited just in front of the abrupt cliff which has been preserved as the present steep surface of the unconformity. Normal faults striking parallel to the surface of the unconformity are found in the basement and by them such a cliff would formed. It is concluded that the collapse basin with 5 km in diameter was formed by the faulting which had thrown down the basin side abut 400 m before deposition of the Sunagohara formation. Before the formation of this collapse basin, the domal uplift which is 25 km in diameter and 500 m in height took place. Judging from that the collapse basin was filled with pyroclastic rocks which was deposited soon after the collapse, the domal uplift is ascribed to the magmatic activity. The other uplift with the axis of NW-SE trend, which was no relation to volcanism had took place in this region before the domal uplift.抄録全体を表示PDF形式でダウンロード (3245K) -
日本橋ナウマンゾウ研究グループ原稿種別: 本文
1978 年 32 巻 2 号 p. 83-85
発行日: 1978/03/25
公開日: 2017/07/26
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隆起海蝕洞からミラビライトの産出寒河江 登志朗, 町田 明夫, 昼間 明, 堀口 万吉原稿種別: 本文
1978 年 32 巻 2 号 p. 86-87
発行日: 1978/03/25
公開日: 2017/07/26
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平岩 五十鈴, 与語 節生原稿種別: 本文
1978 年 32 巻 2 号 p. 88-98
発行日: 1978/03/25
公開日: 2017/07/26
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清水 大吉郎原稿種別: 本文
1978 年 32 巻 2 号 p. 99-106
発行日: 1978/03/25
公開日: 2017/07/26
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日本の第四紀層の14C年代(122)遠藤 邦彦, 村井 公一原稿種別: 本文
1978 年 32 巻 2 号 p. 107-108
発行日: 1978/03/25
公開日: 2017/07/26
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日本の第四紀層の14C年代(123)大池 昭二原稿種別: 本文
1978 年 32 巻 2 号 p. 109-110
発行日: 1978/03/25
公開日: 2017/07/26
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ミラシン A.P., 青木 斌, 石田 光男原稿種別: 本文
1978 年 32 巻 2 号 p. 111-iii
発行日: 1978/03/25
公開日: 2017/07/26
ジャーナル オープンアクセスPDF形式でダウンロード (406K)
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