Report on DELP 1985 Cruises in the Japan Sea : Part III : Seismic Reflection Studies in the Yamato Basin and the Yamato Rise Area

スポンサーリンク

概要

• 論文の詳細を見る

• A stratigraphic sequence in the Yamato Basin is acoustically distinguished between the central and northeastern portions. In the central portion we can identify at least six acoustic units. Units except acoustic basement and volcanic apron sediments distributed around the Yamato Seamounts Chain are correlated with four detrital turbidites from middle Miocene to Recent. The Toyama Deep Sea Fan, uppermost unit, has been formed since 0.5 Ma based on the drilling result of DSDP Site 299. The huge sediments supply to the Yamato Basin through the Toyama Deep Sea Channel was presumably caused by the uplift of the Hida Mountains. The acoustic basement of the Yamato Basin is characterized by smooth morphology associated with low frequency stratified reflectors when compared to normal oceanic layer II. We propose that the acoustic basement is composed of an alternation of sediments and sill. The Yamato Seamounts Chain aligning in NE-SW direction in the central portion of the Yamato Basin was built by the same volcanism responsible for the basalt sill. Northeast of 39°40'N, an acoustic basement shows morphologically high relief and the stratigraphic sequence differs from that in the central portion. The high relief is identified with the eastern extension of the Yamato Rise. It is thought that the high relief of the acoustic basement and the Yamato Rise structurally separate the Yamato Basin from the Japan Basin.大和海盆の音響層序は中央部と北東部で区別される.中央部では少なくとも6層が音響的に識別される.基盤および大和海山列周辺に見らるvolcanic apron sedimentsをのぞいた各層はMiddleMioceneからHoloceneの4層の砕屑性乱泥流堆積物に対比される.富山深海扇状地は最上位層に相当し,その形成は約50万年前から始まったと考えられ,これは飛騨山脈の隆起により大量の堆積物がもたらされた結果であろう.音響的基盤はその上面が平坦であること,また内部に反射面を持つことで特徴づけられ,堆積物とそれに貫入したシルから構成されていると推測される.海盆中央に北東-南西方向に配列している大和海山列はシルをもたらしたと同じ火成活動により形成されたものと思われる.この火成活動の年代は,背弧拡大により海盆が形成されたと考えられる15Ma前と同時かあるいはわずかに後と思われる.大和海盆の北緯39°4'より北東では層序が異なり,しかも音響的基盤は地形的にせり上がっている.この基盤の高まりの西延長が大和堆に当たる.つまり大和堆を含めた基盤の高まりが大和海盆と日本海盆を構造的に区分している.

• 東京大学地震研究所,Earthquake Research Institute, University of Tokyo,東京大学海洋研究所,千葉大学理学部の論文
• 1988-03-31

著者

• SUYEHIRO Kiyoshi

  IFREE, Japan Agency for Marine-Earth Science and Technology

• Taira Asahiko

  Ocean Research Institute University Of Tokyo

• Tamaki K

  Univ. Tokyo Tokyo Jpn

• Tokuyama Hidetoshi

  Faculty Of Pharmaceutical Sciences The University Of Tokyo

• TOKUYAMA HIDEKAZU

  Ocean Research Institute, University of Tokyo

• Suyehiro Kiyoshi

  Ifree Japan Agency For Marine-earth Science And Technology

• Shimamura Kiyoshi

  Ifree Japan Agency For Marine-earth Science And Technology

関連論文

• Report on DELP 1985 Cruises in the Japan Sea : Part VII : Topography and Geology of the Yamato Basin and Its Vicinity
• Aftershock observation of the 2003 Tokachi-oki earthquake by using dense ocean bottom seismometer network
• Photocytotoxicity of Water-soluble Fullerene Derivatives
• Aftershock distribution of the 26 December 2004 Sumatra-Andaman earthquake from ocean bottom seismographic observation
• Report on DELP 1988 Cruises in the Okinawa Trough : Part 2. Seismic Reflection Studies in the Southwestern Part of the Okinawa Trough
• Report on DELP 1987 Cruises in the Ogasawara Area : Part III : Seismic Refraction Experiment Using Airgun-OBSH for Fine Crustal Structure across the Ogasawara Trough along East-West Track Line
• Report on DELP 1987 Cruises in the Ogasawara : Part II : Seismic Reflection Studies in the Ogasawara Trough
• Report on DELP 1986 Cruises in the Northwestern Pacific : Part II: Oceanic Crust of the Basin
• Report on DELP 1987 Cruises in the Ogasawara Area : Part IV : Explosion Seismic Refraction Studies
• New Self-Contained Deep-Towed Proton Magnetometer System
• A Universal Marine Geophysical Data Processing System
• Seasonal Response of Planktonic Foraminifera to Surface Ocean Condition:Sediment Trap Results from the Central North Pacific Ocean
• Hypocenter distribution of plate boundary zone off Fukushima, Japan, derived from ocean bottom seismometer data
• Report on DELP 1985 Cruises in the Japan Sea : Part II : Seismic Refraction Experiment Conducted in the Yamato Basin, Southeast Japan Sea
• Nature and growth rate of the Northern Izu-Bonin (Ogasawara) arc crust and their implications for continental crust formation
• MARINE GEOLOGY AND SUBCRUSTAL STRUCTURE OF THE SHIKOKU BASIN AND THE DAITO RIDGES REGION IN THE NORTHERN PHILIPPINE SEA
• SUBBOTTOM GEOLOGICAL STRUCTURES OF SAGAMI BAY
• Ocean Downhol Seismic Project
• Origin of the Magnetic Anomalies in the Southern Okinawa Trough
• Oceanic crust and Moho of the Pacific Plate in the eastern Ogasawara Plateau region
• Implications from the seismic crustal structure of the northern Izu-Bonin arc
• Aftershocks and Faults of the Hyogo-ken Nanbu Earthquake beneath Akashi Strait (The 1995 Hyogo-ken Nanbu Earthquake(Part 1))
• Biological Activity of Water-Soluble Fullerenes. Structural Dependence of DNA Cleavage, Cytotoxicity, and Enzyme Inhibitory Activities Including HIV-Protease Inhibition
• Evolution of an accretionary complex along the north arm of the Island of Sulawesi, Indonesia
• Report on DELP 1985 Cruises in the Japan Sea : Part III : Seismic Reflection Studies in the Yamato Basin and the Yamato Rise Area
• Subbottom structure in the eastern Japan Basin:Preliminary reports of the Japan-USSR Joint Japan Sea Geophysical Research
• Aftershock distribution of the 26 December 2004 Sumatra-Andaman earthquake from ocean bottom seismographic observation

もっと見る 閉じる

スポンサーリンク