巻号一覧
60 巻, 707 号
選択された号の論文の9件中1～9を表示しています
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小西 健二1954 年 60 巻 707 号 p. 325-332
発行日: 1954/08/25
公開日: 2008/04/11
ジャーナル フリーAn Early Jurassic strata recently discovered near Yamaoku, Kamiosakabe-mura, Atetsu-gun, Okayama Prefecture, in the Chugoku Mountainland (Maps 1-3) are described., The strata, composed mainly of coarse sandstone, and partly of conglomeratic sandstone and sandy shale, were named the Yamaoku formation., The formation does not show any fine cyclic sedimentation., On the basis of successive changes in lithology and some other facts, the strata are classified into three units as shown in Tables 1-2 and Maps 3-3'., Rock facies and fossil contents of the formation suggest that it was deposited rather rapidly on the metamorphosed Palaeozoic basement., Granitic and volcanic (andesitic to basaltic) detritus were received from the surrounding areas and were deposited in a littoral to brackish (paralic) zone, which was in a somewhat labile condition., Though fossils are scarce (Table 3), the Yamaoku formation may be correlated with a part of the Liassic "Kuruma group" in Nagano, Niigata, and Toyama Prefectures.,抄録全体を表示PDF形式でダウンロード (1117K) -
佐藤 良昭1954 年 60 巻 707 号 p. 333-336
発行日: 1954/08/25
公開日: 2008/04/11
ジャーナル フリーHeavy minerals have been collected from the coarse sandstones of the Jurassic Yamaoku formation., These minerals are allanite, anatase, augite, biotite, clinozoisite, epidote, garnet, hornblende, muscovite, rutile, titanite, tourmaline, zircon, zoisite, and opaque minerals such as hematite, ilmenite, magnetite, and pyrite., Three zones of heavy mineral associations are recognized in the formation., These zones transect the lithologic boundaries of the formation., The cause of this transection is not clear., The source materials of the sediments may be granitic, andesitic, and basaltic rocks as well as pre-Jurassic sedimentary rocks.,抄録全体を表示PDF形式でダウンロード (487K) -
木村 春彦1954 年 60 巻 707 号 p. 337-348
発行日: 1954/08/25
公開日: 2008/04/11
ジャーナル フリーExperimental studies on the mode of movement, stability, and transportation of sedimentary particles are described, and the following points are clarified:(1) In the deposition of saltant particles, they come to a stop after the process of traction, while suspended particles do so without perceptible traction., When settled particles are set in motion again, the processes are reverse., (2) The critical condition required for saltation is given as follows: d/V4≒1., 5×l0<-9> (c·g·s) at 7., 5°C., The letter d is the diameter of a particle and V is the current velocity near the bottom., However, in case d less than about 0., 1mm., the particle stays in suspension., (3) If V is a little greater than the critical current velocity required for the traction of sorted aggregate particles, the traction of the individual particle is repeated intermittently, but after a little while this traction comes to a stop and the sedimentary particles, on the whole, become stable., In this case, the smaller the size or the fewer the quantity of the sedimentary particles, the longer the time required to attain stable conditions., (4) The V required to remove the stabilized particles may be regarded as a critical current velocity required for erosion (cf., part 3)., If d is less than about 0., 1mm., this velocity becomes large with the elapsed time after the deposition., (5) The above stabilization is due to compaction by settling of the sediment, and this causal action increases abruptly when d becomes about 0., 1mm., or less., (6) On the unstabilized bed the transported (or eroded) quantity 'Tw ' of bed material varies not only with V but also with d of bed particles, namely Tw is expressed as follows: Tw∽V-(4log10d+1)(c·g·s) at 10°C., As stated above, it must be noticed that d≒0., 1mm., is a kind of critical point of abrupt changes in the phenomena related to the sedimentation process and that this d also corresponds to one of the critical points of 'settling velocity' or 'proper critical velocity of current' (cf., part 2).,抄録全体を表示PDF形式でダウンロード (1385K) -
鈴木 淑夫1954 年 60 巻 707 号 p. 349-356
発行日: 1954/08/25
公開日: 2008/04/11
ジャーナル フリーThe results of field and laboratory investigations, with special reference to the modal analysis of the rocks from the plutonic mass in the vicinity of Tono, are discussed., The mass is composed generally of quartz, potash feldspar, plagioclase, biotite and hornblende showing a granodioritic nature, although parts of the mass show gabbroic facies consisting essentially of pyroxene and more basic plagioclase., It is remarkable that the direction of distribution of the rock facies bears a close resemblance to the general tectonic structure in the district, indicating the possibility of correlating the tectonic movements with the igneous injection., The tectonic movements and the igneous injection are believed to have occurred in late Cretaceous time., The heterogeneity of the igneous mass probably implies that the mass was intruded as a mixture of semi-consolidated basic rocks and more fluid granitic materials., The mixing may have occurred prior to intrusion, at a time when the materials were at considerable depth.,抄録全体を表示PDF形式でダウンロード (991K) -
山際 延夫1954 年 60 巻 707 号 p. 356
発行日: 1954/08/25
公開日: 2008/04/11
ジャーナル フリーPDF形式でダウンロード (279K) -
富澤 恒雄1954 年 60 巻 707 号 p. 357
発行日: 1954/08/25
公開日: 2008/04/11
ジャーナル フリーPDF形式でダウンロード (304K) -
立岩 巖, 生越 忠, 加藤 昭1954 年 60 巻 707 号 p. 358-359
発行日: 1954/08/25
公開日: 2008/04/11
ジャーナル フリーPDF形式でダウンロード (429K) -
松本 達郎1954 年 60 巻 707 号 p. 359
発行日: 1954/08/25
公開日: 2008/04/11
ジャーナル フリーPDF形式でダウンロード (297K) -
小貫 義男, 工藤 一1954 年 60 巻 707 号 p. 360-362
発行日: 1954/08/25
公開日: 2008/04/11
ジャーナル フリーPDF形式でダウンロード (508K)
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