| JaLCDOI | 10.18926/ESR/13885 |
|---|---|
| Title Alternative | Miocene Ukan Formation, Ukan Area, Okayama Prefecture, Southwest Japan |
| FullText URL | ESR_8_1_1.pdf |
| Author | Fujiwara, Takao| Taguchi, Eiji| Suzuki, shigeyuki| |
| Abstract | In this paper, we deal with the Miocene Ukan Formation, sporadically distributed in Ukan-cho, Okayama prefecture, from a viewpoint of analysis of lithology and molluscan assemblages. The Ukan Formation is lithostratigraphically divided into the Suzuoka Conglomerate, Yamagata Muddy Sandstone, Shimoyokomi Sandstone and Conglomerate, Azechi Sandstone and Conglomerate, Tsuneyama Siltstone Members in ascending order. The following 6 molluscan assemblages are recognized. The lower four members and the last member is correlative to the Lower Sandstone and Upper Shale Formation of the Bihoku Group, respectively judging from lithology and fauna. The temporal chages of the above mentioned molluscan assemblages represents that gradual deeping of sea during the depositional period from the Suzuoka Conglomerate and Yamagata Muddy Sandstone Members to the Azechi Sandstone and Conglomerate Member via the Shimoyokomi Sandstone and Conglomerate Member, and abrupt deeping of sea seems to have happened between the Azechi Sandstone and Conglomerate Member and the Tsuneyame Siltstone Member. |
| Keywords | Lithology Molluscan assemblage Paleoenvironmental change Ukan Miocene |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2001-09-20 |
| Volume | volume8 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 12 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310604 |
| Author | Fujiwara, Takao| Suzuki, Shigeyuki| |
|---|---|
| Published Date | 2002-09-20 |
| Publication Title | Okayama University Earth Science Report |
| Volume | volume9 |
| Issue | issue1 |
| Content Type | Departmental Bulletin Paper |
| JaLCDOI | 10.18926/ESR/13880 |
|---|---|
| Title Alternative | Pyrite spots formed along slaty cleavage texture of pelitic rocks of the Tamba Belt, Ujitawara Town, Kyoto Prefecture, Southwest Japan. |
| FullText URL | ESR_9_19.pdf |
| Author | Mikami, Teiji| Musashino, Makoto| Suzuki, shigeyuki| |
| Abstract | Pyrite spots were identified in pelitic rocks from the Ujitawara area, southernmost part of Tamba belt. XMA analysis shows that the spots are composed of pyrite. The spots occur along slaty cleavage plane and form spotted shape of diameter of about 5mm. |
| Keywords | The Tamba Group Ujitawata pelitic rocks pyrite spots slaty cleavage |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2002-09-20 |
| Volume | volume9 |
| Issue | issue1 |
| Start Page | 19 |
| End Page | 24 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310485 |
| JaLCDOI | 10.18926/ESR/13875 |
|---|---|
| Title Alternative | Depositional environments of the Katsuta Group, eastern Tsuyama Basin, Southwest Japan |
| FullText URL | earth_science_reports_010_1_23.pdf |
| Author | Yamasaki, Ryo| Suzuki, Shigeyuki| |
| Abstract | The Miocene Katauta Group of the Syohoku-cho area is subdivides into 6 members ; The Uetsuki Conglomerate Member, Nara Sandy Mudstone Member, Tai Gravelly Sandstone Member, Takatori Conglomerate Member, Ayabe Mudstone Member and Maruyama Mutstone Member from bottom to top. The unconformity between Miocene deposits and basement rocks in this area was traced to obtain geometry of the Miocene basin. Contour maps of the bases of the Miocene Yoshino Formation and Takakura Formation indicate paleo-topography. The obtained topography demonstrates a valley, which flowed to north-west, and a few islands and bays. It indicates that these Miocene successuions were deposited in the topography which resemble to the present Seto Inland. |
| Keywords | Katsuta Group Tsuyama Basin Miocene geometry of basin paleoenvironmental chage |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2003-12-20 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 23 |
| End Page | 31 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310475 |
| JaLCDOI | 10.18926/ESR/13874 |
|---|---|
| Title Alternative | Distributions and ages of the Paleogene deposits in the Kibi Plateau Area, and Paleogene paleogeography |
| FullText URL | earth_science_reports_010_1_15.pdf |
| Author | Tanaka, Hajime| Suzuki, Shigeyuki| Hotani, Shu| Yamamoto, Yasuo| Danhara, Tohru| |
| Abstract | The "Kibi Plateau" forms a unique geomorphic province with the gently-sloping and stable continental feature. Gravel deposites called the "Mountain Gravels", are distributed sporadically in the Kibi Plateau, and have been considered Pliocene deposits. However, recent fission-track ages of the tuff beds intercalated in the deposits have indicated that the ago of deposits are Paleogen in the age. So far, fission-track ages (using zircon) of 61 to 65, 55, 37, 34 to 35 and 27 Ma are obtained. Remaining the belt-like distributions of the Paleogene gravelly valley-full deposits suggest that the Kibe Plateau has been keeping as a stable block, and repeated periods of incision followed by sedimentation of valley-fill deposits are occurred in the area during Paleogene period. |
| Keywords | Kibi Plateau gravelly valley-fill deposites fission-track ages Paleogene palaeogeography |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2003-12-20 |
| Volume | volume10 |
| Issue | issue1 |
| Start Page | 15 |
| End Page | 22 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310517 |
| JaLCDOI | 10.18926/ESR/13870 |
|---|---|
| Title Alternative | Paleoenvironmental Analyses of the Buried Peat Deposit during the mid-Holocene at the Desaki Coast in Tamano City, Okayama Prefecture, Weatern Japan |
| FullText URL | earth_science_reports_011_1_39.pdf |
| Author | Matsushita, Mariko| Sato, Hiroshi| Suzuki, Shigeyuki| Yukumoto, Koichi| Momohara, Arata| Ueda, Yayoi| Katoh, Shigehiro| Maeda, Yasuo| |
| Abstract | The buried peat deposit was foud in the sand beach on the Desaki coast (Tamano City, Okayama Prefecture), the northeastern coast of Seto Inland Sea. In this study, we performed sulfur and diatom analyses of the deposit. The results were used along with 14C dates and the eruption age (7300 cal BP) of Kikai-Akahoya tephra (K-Ab) to derive sedimentary environments of the deposit. K-Ah was detected just below the peat deposit. At the culmination of the Jomon transgression, the peat deposit had been formed in brackish environments of salt marsh for about 300 years. In order to reconstruct local paleovegetation, we analyzed pollen, wood and plant fossils in the deposit. The results show vegetational transition from a deciduous broadleaved forest mainly of Ouercus subgen. Lepidobalanus to Pinus forest. In spite of the Holocene thermal optimum, the vegetation dominated by Ouercus subgen. Cyclobanopsis was not recognized at the Desaki site, as has been shown in many other regions of regions of western Japan. Ouercus sect. Prinus was replaced by Ouercus sect. Aegilops as the dominant section of Ouercus subgen. Lepidobalanus, suggesting early establishment of traditional rural vegetation of 'Satoyama' in Japan. However, no evidence for human agency has been obtained from the mid-Holocene archaeological sites around the Desaki site. Thus it is more likely that this vegetational transition resulted from the succession caused by natural forces such as ecological disturbance and climatic and/or endemic situations rather than by cultural deforestation. |
| Keywords | Desaki coast diatom remains Jomon transgression Kikai-Akahoya tephra mid-Holocene Paleoenvironment peat deposit plant fossils |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2004-12-31 |
| Volume | volume11 |
| Issue | issue1 |
| Start Page | 39 |
| End Page | 47 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310603 |
| JaLCDOI | 10.18926/ESR/13869 |
|---|---|
| Title Alternative | Relative sea-level changes of the Okayama Plain Area during the Holocene, Southwest Japan |
| FullText URL | earth_science_reports_011_1_33.pdf |
| Author | Suzuki, Shigeyuki| |
| Abstract | Postglacial relative sea-level change of the Okayama Plain Area has been analyzed. Former sea-levels were recognized by using peat beds and marine organisms which are also available for 14C dating. Peat beds were rhought to be formed under a stable sea-level condition. 14C ages of the analyzed peat beds were seprated by 4 groups ; 30～18 ka BP, 11～8 ka BP, 6～4 ka BP and 3～2.5 ka BP, indicate 4 stable sea-level periods. 2 transgressive events (18～11 ka BP and 8～6 ka BP) and one regressive event (3.5?～3 ka BP) were also inferred. |
| Keywords | sea-level change peat bed Holocene Okayama Plain |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2004-12-31 |
| Volume | volume11 |
| Issue | issue1 |
| Start Page | 33 |
| End Page | 37 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310268 |
| JaLCDOI | 10.18926/ESR/13847 |
|---|---|
| Title Alternative | Geology of Holocene deposits in Mizushima Area, Okayama Prefecture, Japan |
| FullText URL | EAR_13_1_15.pdf |
| Author | Suzuki, Shigeyuki| |
| Abstract | The study srea, Mizushima is occupied by polder and reclaimed land. The ground of this area is composed of the Holocene deposits below the surface. The deposits are mostly 10 to 20m in thickness and composed of 2 units, the B Unit and C&D Unit. The B Unit is composed of muddy sand with 2 to 3m in thickness. This unit is thought to be deposited in the mouth of paleoriver. The C&D Unit is composed of marine mud and sand with 10 to 15m in thickness. This unit is especially soft and will expand ground oscillations during an earthquake. |
| Keywords | Holocene deposits Mizushima Area Ground oscillation |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2006-03-31 |
| Volume | volume13 |
| Issue | issue1 |
| Start Page | 15 |
| End Page | 18 |
| ISSN | 1340-7414 |
| language | Japanese |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310562 |
| JaLCDOI | 10.18926/ESR/13844 |
|---|---|
| Title Alternative | バングラディシュの更新世台地の地形と地質 |
| FullText URL | EAR_13_1_1.pdf |
| Author | Towhida Rashid| Md. hossain Monsur| Suzuki, Shigeyuki| |
| Abstract | With regards to the origin and evolution of the Pleistocene tracts (Lalmai, Madhupur and Barind tracts) of Bangladesh, two trends of thoughts are common. Most of the authors believed that the Madhupur, Barind and Lalmai tracts represent tectonically uplifted surface. Some researchers have different opinion and they believed that the Lalmai hills and the Madhupur locality represent tectonically uplifted blocks but the whole Barind tract and the major portion of the Madhuput tracts are not tectonically uplifted, rather these are originated by erossional-depositional processes. In order to solve the problems associated with origin and evolution of Pleistocene tracts of Bangladesh, further study is needed. Borehole data may be collected and fusion images can be prepared from aerial photographs and setellite images to detect netectonic imprins and geomorphological signatures of the areas. Elaborate laboratory analysis of sediment deposits, radiocarbon dating my indicate a new dimension about the origin and evolution of these tracts. |
| Keywords | Bangladesh Lalmai Hill Barind Tract Madhupur Tract Neotectonices Aerial photographs Satellite Image Fusion Image |
| Publication Title | Okayama University Earth Science Report |
| Published Date | 2006-03-31 |
| Volume | volume13 |
| Issue | issue1 |
| Start Page | 1 |
| End Page | 13 |
| ISSN | 1340-7414 |
| language | English |
| Copyright Holders | 岡山大学地球科学研究報告編集委員会 |
| File Version | publisher |
| NAID | 120002310445 |
