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Volume 44 (1979)
- Issue 6 Pages 367-
- Issue 5 Pages 233-
- Issue 4 Pages 175-
- Issue 3 Pages 115-
- Issue 2 Pages 53-
- Issue 1 Pages 1-
Volume 44, Issue 5
Displaying 1-15 of 15 articles from this issue
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[in Japanese]1979 Volume 44 Issue 5 Pages 233-236
Published: 1979
Released on J-STAGE: March 27, 2008
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[in Japanese]1979 Volume 44 Issue 5 Pages 237-243
Published: 1979
Released on J-STAGE: March 27, 2008
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[in Japanese]1979 Volume 44 Issue 5 Pages 244-251
Published: 1979
Released on J-STAGE: March 27, 2008
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Kiyoshi MASATANI1979 Volume 44 Issue 5 Pages 254-259
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSBoth the "Ishikari-Kitakami Belt" and "Tomakomai Ridge" are traced from the Kitakami province in northeastern Honshu to the Rebun island off northwestern Hokkaido passing through the Ishikari depression. The former consists of early Cretaceous porphyrites and andesitic volcanic rocks. The basement complex penetrated by Shintotsugawa-1", "Sorachi (MITI)" and "Namporo (MITI)" wells, belongs to the "Ishikari-Kitakami Belt". Both of these tectonic belts correspond to the front of the Northeast Japan Arc, and formed western marginal uplift zone in a geosyncline during the Cretaceous and Palaeogene.
From the Umaoi hill to the Yufutsu offshore area (from north to south), in a narrow belt thick volcanic rocks of the Takinoue stage (early Miocene) unconformably covers the Palaeogene sediments pinching out westward.
Though during which are roughly grouped the Kawabata age (middle Miocene), many isolated subbasins grew in two large basins, which were separated by an uplift zone running through the Rebun island-Kabato-Namporo-Tomakomai into the Tempoku-Hidaka basin in the east and the Ishikari basin in the west. The Hidaka orogenesis influenced only on the development of the Tempoku-Hidaka basin and the uplift zone were not affected any more by the orogenesis.View full abstractDownload PDF (732K) -
Hirohiko YAMAMOTO1979 Volume 44 Issue 5 Pages 260-267
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSIn the Sea of Okhotsk off the northern Hokkaido island, two sedimentary basins and two basement plateaus are present. The former are the Esashi-Monbetsu Oki basin and the Abashiri-Kitami Yamato-tai basin, and the latter are the Monbetsu Oki basement plateau and the Okhotsk basement plateau.
The Tenpoku sedimentary basin extends over the northwestern Hokkaido nearly to the Rebun island. The author concludes that foldings on the eastern flank of the basin is controled by several lines of thrust fault system almost parallel to the eastern mountainous terrains and also ascribed to diapirism or flow of the middle Miocene shale (Masuporo formation). These faulting system is estimated to be derived from upheaval of the eastern margin of the basin during Neogene time.View full abstractDownload PDF (1629K) -
Naomoto KOMATSU1979 Volume 44 Issue 5 Pages 268-271
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSThe offshore sedimentary basin of northeastern Honshu is occupied by the sedimentary rocks of Cretaceous, Paleogene and Neogene age.
The Cretaceous sedimentary basin is inferred to develop beyond the continental margin.
The Paleogene and early Miocene sediments distribute in nearshore and continental shelf area.
Late Miocene sediments uncoformably cover the pre-late Mioocene sequences. The sediments of presumed Pliocene age onlap late Miocene sediments.View full abstractDownload PDF (505K) -
Akitoshi INOMA, Eiichi SASAKI1979 Volume 44 Issue 5 Pages 272-278
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSThis paper represents the toctonic framework of the shelf off Tokai region based on the seismic, gravity and magnetic data. The stable shelf at the northwestern part, the central uplift which may be the extention of the "Akaishi Ressen (rift)", and the outer marginal uplift at the southeastern part are prominent structures in this area. In addition to the eustatic subsidence after the middle Miocene and after Pleistocene and eustatic rising before the Pleistocene, relative upheaval of the outer marginal uplift has successively occurred. The structural movement in this area may be explained with a model that the southern oceanic crust has thrust down under the continental crust.View full abstractDownload PDF (997K) -
Yoshihisa OKUDA, Makoto KUMAGAI, Kiyuh TAMAKI1979 Volume 44 Issue 5 Pages 279-290
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSSeveral deep sea terraces are present on the continental slope off southwest Japan, extending parallel to the Nankai Trough. A thick sequence of Neogene and Quaternary age beneath the terrace rests uncomformably upon Oligocene to lower Miocene strata (M Formation). Most of the sequence is trapped by an outer structural ridge. The sequence is divided into the T, K1, K2, K3 and P Formations.
The T Formation of early to middle Miocene age is mainly composed of flysh-like sediments. Plutonic rocks such as Kumano acidic rocks were intruded during the middle Miocene.
The K1 Formation of late Miocene to early Pliocene age unconformably overlies the T Formation, and its distribution is roughly concordant with that of sedimentary basins beneath the deep sea terraces. The formation of these basins probably has a close relation to the block movement of the area accompanied by igneous events and regression during the middle Miocene.
The K2 Formation of middle to late Pliocene age shows the sedimentary structure of rapid transgressive overlapping. The early-Pliocene turbidites in the Nankai trough incline toward the continental slope. So the terraces might have subsided more than 2, 000 meters by downwarping in relation to the Shikoku basin and the southwest Japan islands.
The depocenter of the K3 Formation of early Pleistocene moved northward in relation to that of the K2 Formation.
The P Formation of middle Pleistocene to Holocene occurring in ponded subbasins in each terrace, has flat surface. Probably, another block-faulting stage began during this time.View full abstractDownload PDF (1993K) -
Uko SUZUKI1979 Volume 44 Issue 5 Pages 291-307
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSThe gelogical development of the sedimentary basins in the Sea of Japan, Northern Honshu and the petroleum geology of the area are studied.
Through this study, 16, 000km seismic data were interpreted and 25 offshore wells were analyzed. The seismic data were used for the studies of trap types and timing of their formation and the delineation of sedimentary basin. The well data were analyzed to establish the stratigraphy including time-genetic
units and the stratigraphy was applyed to the adjacent land area to reconstruct the regional paleogeography. Also, well data were used to estimate average deposition rates and to provide Neogen basin models for the area.
According to these study works, it was found that each basin of this area seem to be developed under the influence of following factors.
A. The regional north-westward shifting of depocenter with time.
B.The local structural movements such as the differentiation of basins in upper middle Miocene and the modification of them during upper Miocene to Recent.
C. The global transgression and regression.
The petroleum geology of the area are summarized as follows. Almost all of mudstones from Miocene to Pliocene are the source rocks for petroleum. The required burial depth for the petroleum generation may range from 2, 000 to 3, 300 meters. The turbidite sands are considered to be the most important reservoir rocks. Trap types seen in the area seem to be controled by the presen structural belts and their trends. Traps were formed mainly in middle Pliocene, with time lag from Late Miocene to Quaternary from place to place.View full abstractDownload PDF (1953K) -
Takashi TANAKA1979 Volume 44 Issue 5 Pages 308-320
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSOnshore and offshore Hokuriku-Sanin basin is a part of green tuff basin. According to the results of recent offshore seismic prospectings, the major part of Hokuriku-Sanin basin is located in the offshore area, and it is divided into three geological provinces from their structural features and thicknesses
of sediments. They are as follows;
Hokuriku province......Noto plateau, offshore Hakui subbasin, offshore Kanazawa subbasin and offshore Fukui subbasin.
Tango province......offshore Tango basin
Sanin province......Oki-Shimane plateau, offshore Tottori basin and Oki trough.
In general, these basins are associated with thick clastic and pyroclastic sediments of middle to late Miocene and Pliocene age. And there are many types of anticlinal structures formed by folding and block movement of basement complex during late Miocene to Pliocene age.
The stratigraphic and tectonic history of this basin is very similar to those of other green tuff basins such as Akita and Niigata, where there were twice removals of depositional center toward Sea of Japan. And the basins were divided into three geological zones (I, II, III) with peculiar geological and structural features.
The offshore basins such as Tottori and Kanazawa corresponding to zone II could be very important for hydrocarbon exploration, because the distribution of most oil and gas fields in Akita and Niigata is limited to a few, particular series of anticlinal structures in the zone II.View full abstractDownload PDF (1667K) -
Akira MINAMI1979 Volume 44 Issue 5 Pages 321-328
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSThis article discusses stratigraphy and geological history of the continental shelf area covering offshore San-in to Tsushima Island, the southwest part of the Sea of Japan.
Geological data from 5 wells and detailed seismic surveys indicate that sediments in the studied area are devided into 4 stratigraphic groups ranging from Oligocene to Recent in age, namely X, N, K and D groups in ascending order.
The oldest X group of Oligocene time comprises paralic sediments including volcanics which deposited in the initial stage of basin-formation. "N" group of mainly lower Miocene time consists of deep marine sediments, representing the highest stage of transgression. Sediments of the K group of middle Miocene
time shows distinct off-lapping depositional pattern during the basin-filling stage. The youngest D group covers these older groups unconformably.
Strong deformation of sediments prior to the deposition of the D group formed many anticlinal structures.
Five exploratory wells were drilled at the selected structures, where only minor gas shows were encountered.
The area provides the enough palaeotemperature to mature the source rocks at moderate depth.View full abstractDownload PDF (1094K) -
Jun-ichi AIBA, Eiichi SEKIYA1979 Volume 44 Issue 5 Pages 329-340
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSThe Nansei-Shoto (Ryukyu Islands) is one of the island arcs along the West Pacific continental margins and has typical topographic features as an island arc, where marginal seas, volcanic fronts, island arcs and trenches are regularly and zonally arranged toward the Pacific Ocean.
Geology and structures of the Ryukyu Islands are partly discortant with the zonal arrangements, and the northern and southern parts of the Ryukyu Islands were under different tectonic conditions before the latest Neogene time. But finally both of them were combined into a present status by the Quarternary
tectonism.
Around the Ryukyu island arc, there are several sedimentary basins mainly consisting of the Neogene sediments.
The Shimajiri basin, a fore arc basin along the outer side of the island arc, is about 1100km long and contains up to 6000m of sediments deposited during the late Miocene to Pleistocene time, and is forming abyssal plain between the island arc and trench.
The Yaeyama basin is also situated in the outer side of the southern Ryukyu arc, but a trend of this fore arc basin is different from that of the himajiri basin. Plio-Pleistocene deposits are unconformably resting on possible early to middle Miocene layers and a total thickness of these sediments attain to 4000 m. Small basins within the older uplift zone such as the Amami trough are collapse basins formed by normal faults and tiltings due to pull-apart. They are filled mostly with Quarternary deposits.
The Okinawa trough is a typical back arc basin, which is formed by extensional tectonic forces and supplied with deltaic or submarine fan deposits from the continent to the west. Sediments in this trough will exceed 5000m at maximum. Many step faults and roll-over anticlines caused by them are commonly
observed on seismic profiles. Characteristically high heat flows are reported in the trough.
The Tokai basin is an older back arc basin compared with the Okinawa trough, and formed between Fukien-Ryeongnam and Goto-Senkaku belts. Presumably, this basin contains early to midde Miocene sand-shale sequences deposited in lagoonal shallow water environments. The presence of large anticlinal structures with gentle dips suggests significant hydrocarbon accumulations in the basin.View full abstractDownload PDF (1391K) -
David Francis NASH1979 Volume 44 Issue 5 Pages 341-351
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSAn interpretation is presented of the Neogene to Recent geological development of an offshore area, located at the northeast end of the Okinawa Trough. The interpretation is based on geophysical and well data obtained by Nishi Nihon and Shin Nishi Nihon Sekiyu Kaihatsu K.K. during exploration in their Tokara/Amami concession area.
Basin development, accompanied by widespread volcanism and strongly influenced by Pre-Tertiary basement structures, commenced in Late Neogene Times with the formation of the Okinawa Basin. Toward the end of the Neogene a further phase of basin formation and volcanism occurred which led to the development of the present day physiography.View full abstractDownload PDF (1944K) -
Eiichi HONZA1979 Volume 44 Issue 5 Pages 352-361
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSSedimentary basins in the arcs of the NW Pacific Rim have many characteristic features which are ranged in the zones parallel to the arc extension. Two domimant basins are recognized in the arc area. They are outer trench belt and inner sedimentary and volcanic belt intercalated by the intermediate uplifted belt between them. Thick sedimentary basins in the outer belt tend to develope in a few particular areas of the arc. The one is in the contact zone of the arc as is suggested along the contact zone of the Tohoku Arc and the remnant Hidaka Arc. The next is in and around the joint zone of the arcs, as is suggested in that of the Tohoku Arc and the Izu-Ogasawara Arc.
Sedimentary basins in the inner belt is thicker than that in the outer belt. Horizontal tentional stress is suggested during the earlier stage of the basin development in the inner belt, which had changed to the horizontal compressional stress in the later stage except in and around the volcanic chain. The horizontal tensional stress which formed thick sedimentary basin in the inner belt might have acted important roll to have dense hydrocarbneferous sediments during the earlier stage.View full abstractDownload PDF (1242K) -
1979 Volume 44 Issue 5 Pages 362-365
Published: 1979
Released on J-STAGE: March 27, 2008
JOURNAL FREE ACCESSDownload PDF (553K)
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