@misc{oai:niigata-u.repo.nii.ac.jp:00004422,
 author = {卜部, 厚志},
 month = {Mar},
 note = {A Pleistocene forearc basin fill of the Toyofusa Group is represented by slope to shelf sediments in the southern part of the Boso Peninsula, NE Japan. The Toyofusa Group is subdivided into the Kanamaribata Formation, Ohi Formation, Higashinagata Formation, Takigawa Formation, Sagashi Formation and Ikenouchi Formation in ascending orders, and correlated with the middle to upper part of the Kazusa Group. The slope to shelf sediments are a northeasterly onlapped clastic wedge and include many volcanic ash layers. Mapping of volcanic ash layers, together with the interpretation of depositional facies, permits identification of stratal terminations, and spatial and temporal variations of depositional environments. This allows sequence-stratigraphic analysis of the slope to shelf sediments of the Toyofusa Group.\nSeven depositional sequences were identified in the Toyofusa Group. Each depositional sequence is identified on the basis of lateral terminations of depositional facies and volcanic ash layers, and facies discontinuities at sequence boundaries. These depositional sequences consist of complete or incomplete assemblages of fundamental building components of lowstand, transgressive, and highstand systems tracts deposits. By correlating each depositional sequence with the stable oxygen isotope sea level index, integrated with the volcanic ash age and paleo-magnetic analysis framework for the Toyofusa Group, periodicity of the depositional sequences of the depositional sequences of the Toyofusa Group can be estimated about 50,000 to 80,000 years of glacio-eustatic sea level changes.\nTurbidite successions of the southwest area of the Toyofusa Group indicate the trough-fill type turbidite basin in the slope environments. Turbidite successions of the Toyofusa Group can be interpreted to consist not only lowstand sea level stage but also transgressive sea level stage. Distinct associations of lowstand, transgressive and highstand systems tracts in the turbidite depositional sequences have sensitively been controlled by relative sea-level changes in a shallow-water environment., 学位の種類: 博士（理学）. 報告番号: 甲第1011号. 学位記番号: 新大院博（理）甲第29号. 学位授与年月日: 平成6年3月22日, 新大院博（理）甲第29号},
 title = {房総半島南端・豊房層群にみられる高周波堆積シークェンス},
 year = {1994}
}