start-ver=1.4
cd-journal=joma
no-vol=32
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2026
dt-pub=20260331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=裏表紙・目次
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=32
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2026
dt-pub=20260331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=岡山大学地球科学研究報告 投稿規定（約款）
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=32
cd-vols=
no-issue=1
article-no=
start-page=33
end-page=44
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2026
dt-pub=20260331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=Large-scale rainfall characteristics at the heavy rainfall event around the western Japan during 5?7 July 2018
kn-title=2018年7月5日?7日の西日本豪雨における広域降水特性
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=　Large-scale rainfall characteristics at the heavy rainfall event around the western Japan for 5?7 July 2018 were analyzed with use of the 10-mimute precipitation data at the surface meteorological observation stations of the Japan Meteorological Agency, and so on. In this case, the area with 3 days total precipitation of near or more than 300 mm was distributed widely from northern Kyushu to Shiga and Fukui Prefectures. As in the many heavy rainfall events around Kyushu District in the mature stage of the Baiu season, contribution of the intense rainfall with more than 4 mm/10-minute (24 mm/h) attained about one third of the areal mean total precipitation. However, it is noted that the "not so intense rain" with less than 2 mm/10-minute (12 mm/h) also contributed to about one third of the huge total precipitation in the wide area. In short, this case could be characterized by the mixture of the western Japan type heavy rainfall event and the eastern Japan type one.
en-copyright=
kn-copyright=

en-aut-name=KATOKuranoshin
en-aut-sei=KATO
en-aut-mei=Kuranoshin
kn-aut-name=加藤内藏進
kn-aut-sei=加藤
kn-aut-mei=内藏進
aut-affil-num=1
ORCID=

en-aut-name=MATSUMOTOKengo
en-aut-sei=MATSUMOTO
en-aut-mei=Kengo
kn-aut-name=松本健吾
kn-aut-sei=松本
kn-aut-mei=健吾
aut-affil-num=2
ORCID=

en-aut-name=OTANIKazuo
en-aut-sei=OTANI
en-aut-mei=Kazuo
kn-aut-name=大谷和男
kn-aut-sei=大谷
kn-aut-mei=和男
aut-affil-num=3
ORCID=

affil-num=1
en-affil=Faculty of Education, Okayama University
kn-affil=岡山大学学術研究院教育学域（理科）

affil-num=2
en-affil=Okayama Gakugeikan High School
kn-affil=岡山学芸館高等学校

affil-num=3
en-affil=TV Setouchi Broadcasting Co., LTD.
kn-affil=テレビせとうち(株)
en-keyword=western Japan heavy rainfall in July 2018
kn-keyword=western Japan heavy rainfall in July 2018
en-keyword=10-minute precipitation data
kn-keyword=10-minute precipitation data
en-keyword=east-west difference of the Baiu precipitation
kn-keyword=east-west difference of the Baiu precipitation
END

start-ver=1.4
cd-journal=joma
no-vol=32
cd-vols=
no-issue=1
article-no=
start-page=21
end-page=31
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2026
dt-pub=20260331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=A trial of lesson practice at the university on the variety of heavy rainfall characteristics based on the 10-minute precipitation data toward promoting the meteorological disaster prevention literacy
kn-title=10分間降水量から大雨の特徴の多様性を捉える大学での授業の試み（防災気象リテラシー育成へ向けて）
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=　In the disaster prevention education on the heavy rainfall around Japan, it is also important to promote the meteorological literacy on the seasonal and regional differences of their rainfall characteristics such as the convective rain or stratiform rain, together with their total amount of precipitation and their occurrence frequency. As the first step toward the above purpose, the present study made a lesson practice for the university students by utilizing the 10-minute precipitation data for the four heavy rainfall events, in which the types of the heavy rainfall (although all the cases examined in the lesson are relating to the deep convective clouds) are rather different from each other, such as the differences of the rainfall intensity at the peak time, short-period variation of the rainfall intensity and the persistency of the rainfall including the "not so intense rainfall". The reports by the students seem to perceive the different features among these events briefly, but the students' attention to how long the intense rainfall with short-period variation or "not so intense rainfall" lasted was not so sufficient.
en-copyright=
kn-copyright=

en-aut-name=KATOKuranoshin
en-aut-sei=KATO
en-aut-mei=Kuranoshin
kn-aut-name=加藤内藏進
kn-aut-sei=加藤
kn-aut-mei=内藏進
aut-affil-num=1
ORCID=

affil-num=1
en-affil=Faculty of Education, Okayama University
kn-affil=岡山大学学術研究院教育学域（理科）
en-keyword=disaster prevention education
kn-keyword=disaster prevention education
en-keyword=variety of the heavy rainfall characteristics
kn-keyword=variety of the heavy rainfall characteristics
en-keyword=meteorological disaster prevention literacy
kn-keyword=meteorological disaster prevention literacy
en-keyword=use of the 10-minute precipitation data
kn-keyword=use of the 10-minute precipitation data
END

start-ver=1.4
cd-journal=joma
no-vol=32
cd-vols=
no-issue=1
article-no=
start-page=9
end-page=19
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2026
dt-pub=20260331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=Petrological study of Sue ware from the Sabukaze kiln site, Okayama Prefecture
kn-title=寒風古窯跡群須恵器の岩石学的研究
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=　The Sabukaze kiln site, a representative ancient tunnel-kiln site in the Kibi region, worked during the Asuka period (from early 7th century to early 8th century) to produce Sue ware including jars, cups, coffins, and ornamental tiles. To determine the provenance of the materials used for the Sue ware, we carried out petrological analyses of 13 Sue sherds, including optical microscopy, X-ray diffractometry, X-ray fluorescence spectroscopy, Raman spectroscopy, and electron-probe analysis. In spite of the difference of production time, all the Sue sherds show close similarities in modal proportion of mineral inclusions with dominant quartz and feldspar, and minor volcanic glass, in chemical compositions of feldspar and interstitial matrix, and in whole-sherd chemical composition. These similarities suggest that the paste materials of the Sabukaze Sue ware were commonly derived from weathered rhyolitic rocks and obtained from the same or neighboring mining site(s) located near the kiln site.
en-copyright=
kn-copyright=

en-aut-name=ANAMITaiji
en-aut-sei=ANAMI
en-aut-mei=Taiji
kn-aut-name=阿南太士
kn-aut-sei=阿南
kn-aut-mei=太士
aut-affil-num=1
ORCID=

en-aut-name=NOZAKAToshio
en-aut-sei=NOZAKA
en-aut-mei=Toshio
kn-aut-name=野坂俊夫
kn-aut-sei=野坂
kn-aut-mei=俊夫
aut-affil-num=2
ORCID=

en-aut-name=KIMURAOsamu
en-aut-sei=KIMURA
en-aut-mei=Osamu
kn-aut-name=木村理
kn-aut-sei=木村
kn-aut-mei=理
aut-affil-num=3
ORCID=

affil-num=1
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学大学院環境生命自然科学研究科

affil-num=2
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学学術研究院環境生命自然科学学域

affil-num=3
en-affil=Department of Archaeology, Osaka University
kn-affil=大阪大学考古学研究室
en-keyword=Sabukaze kiln site
kn-keyword=Sabukaze kiln site
en-keyword=Sue ware
kn-keyword=Sue ware
en-keyword=provenance
kn-keyword=provenance
en-keyword=petrology
kn-keyword=petrology
END

start-ver=1.4
cd-journal=joma
no-vol=32
cd-vols=
no-issue=1
article-no=
start-page=1
end-page=7
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2026
dt-pub=20260331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=Microtremor exploration in Kojima Bay area, Okayama Plain
kn-title=岡山平野児島湾岸部での微動アレイ探査
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=　This report describes microtremor array observations conducted at two sites for deep exploration and three sites for shallow exploration around Kojima Bay area in the southern Okayama Plain. Based on these records, the ground velocity structures were estimated. The results yielded solutions indicating the depth of the top of the seismic base layer (equivalent to 3 km/s layer) ranges from 140 to 300 m, while the depth of the top of the engineering basement layer (equivalent to 0.6 km/s layer) is approximately about 13?14 m. The shallow exploration results also suggested the possible presence of an inversion layer. These estimated velocity structure models provided a reasonable explanation for the observed phase velocities.
en-copyright=
kn-copyright=

en-aut-name=YAMADANobuyuki
en-aut-sei=YAMADA
en-aut-mei=Nobuyuki
kn-aut-name=山田伸之
kn-aut-sei=山田
kn-aut-mei=伸之
aut-affil-num=1
ORCID=

en-aut-name=TAKENAKAHiroshi
en-aut-sei=TAKENAKA
en-aut-mei=Hiroshi
kn-aut-name=竹中博士
kn-aut-sei=竹中
kn-aut-mei=博士
aut-affil-num=2
ORCID=

affil-num=1
en-affil=Faculty of Science and Technology, Kochi University
kn-affil=高知大学理工学部地球環境防災学科

affil-num=2
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学学術研究院環境生命自然科学学域
en-keyword=Okayama Plain
kn-keyword=Okayama Plain
en-keyword=Kojima Bay
kn-keyword=Kojima Bay
en-keyword=Microtremor array exploration
kn-keyword=Microtremor array exploration
en-keyword=S-wave velocity structure model
kn-keyword=S-wave velocity structure model
END

start-ver=1.4
cd-journal=joma
no-vol=32
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2026
dt-pub=20260331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Title Page
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=32
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2026
dt-pub=20260331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=表紙・英文目次
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=31
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2025
dt-pub=20250331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=裏表紙・目次
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=31
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2025
dt-pub=20250331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=岡山大学地球科学研究報告 投稿規定（約款）
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=31
cd-vols=
no-issue=1
article-no=
start-page=1
end-page=15
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2025
dt-pub=20250331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=Improved sedimentary layer model including the accretionary prism in the fore-arc region of the Ryukyu arc, Japan
kn-title=南西諸島の前弧域における付加体を含む堆積層のモデル化
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=　We combine the recent seismic reflection profiles to construct a new seismic velocity model of the sedimentary layer incorporating the accretionary prism along the Ryukyu trench. In constructing the new model, we refer to the zoning (ZONE1 to ZONE4) identified by Okamura et al. (2017, Tectonophys.). The construction process consists of the following steps: First, we digitize either unconformities or VP=4 to 5 km/s lines as the seismic basement, whichever is more clearly identifiable. Second, the digitized thickness data of the sedimentary layer from the reflection profiles are geometrically modeled and interpolated to make the three-dimensional structure model. Finally, we supplement the external region of the constructed 3-D sedimentary model using the J-SHIS model provided by the NIED to complete the velocity structure model in the entire Ryukyu arc. The main features of our model are as follows: In ZONE1, off Ishigaki-jima island, the thick sedimentary layer extends about 50 km wide from the Ryukyu trench. In ZONE2, off Miyako-jima island, the thinner layer compared to the other zones is found near the trench, with a thin sedimentary terrace covering the area behind it. In ZONE3, off Okinawa-jima island, the sedimentary layer deepens as it approaches the trench. In ZONE4, off Tokara islands, the deepest layer among all zones is identified. We then conduct 3-D finite-difference simulations of seismic wave propagation using the new and the previous models to confirm the improvement of the new model. In the simulations, the effects of the accretionary prism along the Ryukyu trench on the seismic wave propagation are clearly identified.
en-copyright=
kn-copyright=

en-aut-name=KOMATSUMasanao
en-aut-sei=KOMATSU
en-aut-mei=Masanao
kn-aut-name=小松正直
kn-aut-sei=小松
kn-aut-mei=正直
aut-affil-num=1
ORCID=

en-aut-name=URAKAMISohei
en-aut-sei=URAKAMI
en-aut-mei=Sohei
kn-aut-name=浦上想平
kn-aut-sei=浦上
kn-aut-mei=想平
aut-affil-num=2
ORCID=

en-aut-name=OKAMOTOTaro
en-aut-sei=OKAMOTO
en-aut-mei=Taro
kn-aut-name=岡元太郎
kn-aut-sei=岡元
kn-aut-mei=太郎
aut-affil-num=3
ORCID=

en-aut-name=TAKENAKAHiroshi
en-aut-sei=TAKENAKA
en-aut-mei=Hiroshi
kn-aut-name=竹中博士
kn-aut-sei=竹中
kn-aut-mei=博士
aut-affil-num=4
ORCID=

affil-num=1
en-affil=Okayama Gakuin University
kn-affil=岡山学院大学

affil-num=2
en-affil=Formerly Department of Earth Sciences, Okayama University
kn-affil=元・岡山大学大学院自然科学研究科

affil-num=3
en-affil=Department of Earth and Planetary Sciences, School of Science, Institute of Science Tokyo
kn-affil=東京科学大学理学院地球惑星科学系

affil-num=4
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学学術研究院環境生命自然科学学域
en-keyword=Sedimentary layer model
kn-keyword=Sedimentary layer model
en-keyword=Accretionary prism
kn-keyword=Accretionary prism
en-keyword=Ryukyu arc
kn-keyword=Ryukyu arc
END

start-ver=1.4
cd-journal=joma
no-vol=31
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2025
dt-pub=20250331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Title Page
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=31
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2025
dt-pub=20250331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=表紙・英文目次
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=30
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2024
dt-pub=20240331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=裏表紙・目次
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=30
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2024
dt-pub=20240331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=岡山大学地球科学研究報告 投稿規定（約款）
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=30
cd-vols=
no-issue=1
article-no=
start-page=21
end-page=35
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2024
dt-pub=20240331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=A new insight into the driving mechanism for plate tectonics?the relationship between tectonic processes and the circumferential tensile forces associated with a rotating planet?
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=　Mantle convection currents are the currently accepted driving force for plate tectonics that have ripped apart the continents and created oceans. Because of these actions, continental collisions and ocean closures have resulted. Our paper challenges the conventional concept and provides an alternate, mathematically justified drive mechanism. The pull-push motions of such convection currents in the upper mantle are here concluded to be too weak to be the driving mechanism.<br>
　Our proposal for such global scale forces concerns the effect of an offset centre of mass of the Earth that results in rotational wobbling. Kepler’s laws of planetary motion demonstrate the rotational behavior of the Earth to be aligned with the Sun on the outward and inward motions of the elliptical orbit. The unbalanced rotation on a fixed gravitational axis results in circumferential stresses on the outer Earth’s rim that is more than strong enough to pull the continental plates apart. The proposed unbalanced rotational stress force equation is shown to be sufficient to drive the cyclic breakup and reassembly of the continental plates, as well as the generation of new oceanic crust and subduction zones. Mantle convection currents are here demonstrated to have a passive rather than active role in the plate movements.
en-copyright=
kn-copyright=

en-aut-name=MAURERRobert
en-aut-sei=MAURER
en-aut-mei=Robert
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=1
ORCID=

en-aut-name=HARKERStuart
en-aut-sei=HARKER
en-aut-mei=Stuart
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=2
ORCID=

en-aut-name=SUZUKIShigeyuki
en-aut-sei=SUZUKI
en-aut-mei=Shigeyuki
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=3
ORCID=

en-aut-name=WHEELERAllan
en-aut-sei=WHEELER
en-aut-mei=Allan
kn-aut-name=
kn-aut-sei=
kn-aut-mei=
aut-affil-num=4
ORCID=

affil-num=1
en-affil=
kn-affil=Maurer Associates C/o Wellhead Metering Systems

affil-num=2
en-affil=
kn-affil=Morningside Petroleum Geology Consultancy Ltd.

affil-num=3
en-affil=
kn-affil=Department of Earth Sciences, Okayama University

affil-num=4
en-affil=
kn-affil=Professional editor of publications
en-keyword=Differential circumferential tensile force
kn-keyword=Differential circumferential tensile force
en-keyword=Rotating Earth
kn-keyword=Rotating Earth
en-keyword=Offset centre of mass
kn-keyword=Offset centre of mass
en-keyword=radius of eccentricity
kn-keyword=radius of eccentricity
END

start-ver=1.4
cd-journal=joma
no-vol=30
cd-vols=
no-issue=1
article-no=
start-page=13
end-page=20
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2024
dt-pub=20240331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=Microtremor exploration in Tsushima Campus, Okayama University
kn-title=岡山大学津島キャンパスおける微動探査
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=　In this report, microtremor array observations were conducted in the Tsushima Campus of Okayama University, and the subsurface velocity structure was estimated from the analysis of the records. The results indicate that a five-layer S-wave velocity structure from the surface to the seismic basement equivalent layer with thicknesses of 8, 24, 80 and 180 m and velocities of 150, 450, 1100, 1700 and 3200 m/s, respectively, is reasonable. This model explains to some extent the observed phase velocity and H/V spectral ratios. It is also consistent with the surface borehole results. Furthermore, the areal characteristics of the H/V spectral ratios were also presented, allowing us to estimate the trend of the ground structure in shallow areas.
en-copyright=
kn-copyright=

en-aut-name=YAMADANobuyuki
en-aut-sei=YAMADA
en-aut-mei=Nobuyuki
kn-aut-name=山田伸之
kn-aut-sei=山田
kn-aut-mei=伸之
aut-affil-num=1
ORCID=

en-aut-name=TAKENAKAHiroshi
en-aut-sei=TAKENAKA
en-aut-mei=Hiroshi
kn-aut-name=竹中博士
kn-aut-sei=竹中
kn-aut-mei=博士
aut-affil-num=2
ORCID=

affil-num=1
en-affil=Faculty of Science and Technology, Kochi University
kn-affil=高知大学理工学部地球環境防災学科

affil-num=2
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学学術研究院環境生命自然科学学域
en-keyword=Okayama
kn-keyword=Okayama
en-keyword=Microtremor array exploration
kn-keyword=Microtremor array exploration
en-keyword=S-wave velocity
kn-keyword=S-wave velocity
en-keyword=H/V spectral ratio
kn-keyword=H/V spectral ratio
END

start-ver=1.4
cd-journal=joma
no-vol=30
cd-vols=
no-issue=1
article-no=
start-page=1
end-page=12
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2024
dt-pub=20240331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=Petrological characteristics of the stone chamber of Tobiotsuka Kofun, Okayama Prefecture
kn-title=鳶尾塚古墳の石室石材の岩石学的特徴
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=　Tobiotsuka Kofun, a tumulus built on the Misu Hills in the Kofun period, has a horizontal stone chamber made of huge stone blocks with a width up to 2 meters or more. To specify the source of the stone blocks, we carried out the measurement of magnetic susceptibility, petrographic observation, and chemical analysis of minerals. The stones are amphibole-biotite granite with phenocrystic large grains of K-feldspar. The back-wall stone of the chamber has higher magnetic susceptibility than ceiling and side-wall stones, which probably results from a higher amount of magnetite formed by the alteration of biotite in the back-wall stone. Furthermore, the back-wall stone is different from ceiling stone in that it has lower XMg [Mg/(Mg + Fe) mole ratio], lower Al, Ti, and Na + K contents and higher Si contents of amphibole, higher XMg of biotite, and shows a tendency to have higher Na (albite component) contents at rims of plagioclase crystals and lower Ti contents of zircon. These characteristics of the back-wall stone are similar to those of granite exposed in the Koshinzan area about 2 km northeast of Tobiotsuka Kofun, whereas the ceiling and side-wall stones are similar to granite outcrops in the vicinity of Tobiotsuka Kofun, e.g., in the Midoriyama area. It is concluded that the quarry for the back-wall was located at a different place from that for the ceiling and side-wall stones.
en-copyright=
kn-copyright=

en-aut-name=KANEKOTakahiro
en-aut-sei=KANEKO
en-aut-mei=Takahiro
kn-aut-name=金子峻大
kn-aut-sei=金子
kn-aut-mei=峻大
aut-affil-num=1
ORCID=

en-aut-name=NOZAKAToshio
en-aut-sei=NOZAKA
en-aut-mei=Toshio
kn-aut-name=野坂俊夫
kn-aut-sei=野坂
kn-aut-mei=俊夫
aut-affil-num=2
ORCID=

en-aut-name=SEIKEAkira
en-aut-sei=SEIKE
en-aut-mei=Akira
kn-aut-name=清家章
kn-aut-sei=清家
kn-aut-mei=章
aut-affil-num=3
ORCID=

affil-num=1
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学大学院自然科学研究科

affil-num=2
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学学術研究院環境生命自然科学学域

affil-num=3
en-affil=Department of Archaeology, Okayama University
kn-affil=岡山大学学術研究院社会文化科学学域
en-keyword=Tobiotsuka Kofun
kn-keyword=Tobiotsuka Kofun
en-keyword=stone chamber
kn-keyword=stone chamber
en-keyword=granite
kn-keyword=granite
END

start-ver=1.4
cd-journal=joma
no-vol=30
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2024
dt-pub=20240331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Title Page
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=30
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2024
dt-pub=20240331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=表紙・英文目次
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=29
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=20230331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=裏表紙・目次
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=29
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=20230331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=岡山大学地球科学研究報告 投稿規定（約款）
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=29
cd-vols=
no-issue=1
article-no=
start-page=65
end-page=66
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=20230331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=ERRATA: FDM simulation of long-period ground motions around Oita Prefecture, Japan, using a land-ocean unified 3D structure model
kn-title=訂正：地形を考慮した陸海統合3次元地震波速度構造モデルを用いた大分県周辺の長周期地震動シミュレーション
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=

en-aut-name=OKUNAKATatsuya
en-aut-sei=OKUNAKA
en-aut-mei=Tatsuya
kn-aut-name=奥仲達也
kn-aut-sei=奥仲
kn-aut-mei=達也
aut-affil-num=1
ORCID=

en-aut-name=KOMATSUMasanao
en-aut-sei=KOMATSU
en-aut-mei=Masanao
kn-aut-name=小松正直
kn-aut-sei=小松
kn-aut-mei=正直
aut-affil-num=2
ORCID=

en-aut-name=TAKENAKAHiroshi
en-aut-sei=TAKENAKA
en-aut-mei=Hiroshi
kn-aut-name=竹中博士
kn-aut-sei=竹中
kn-aut-mei=博士
aut-affil-num=3
ORCID=

en-aut-name=YOSHIMIMasayuki
en-aut-sei=YOSHIMI
en-aut-mei=Masayuki
kn-aut-name=吉見雅行
kn-aut-sei=吉見
kn-aut-mei=雅行
aut-affil-num=4
ORCID=

en-aut-name=NAKAMURATakeshi
en-aut-sei=NAKAMURA
en-aut-mei=Takeshi
kn-aut-name=中村武史
kn-aut-sei=中村
kn-aut-mei=武史
aut-affil-num=5
ORCID=

en-aut-name=OKAMOTOTaro
en-aut-sei=OKAMOTO
en-aut-mei=Taro
kn-aut-name=岡元太郎
kn-aut-sei=岡元
kn-aut-mei=太郎
aut-affil-num=6
ORCID=

affil-num=1
en-affil=Formerly Department of Earth Sciences, Okayama University
kn-affil=元・岡山大学理学部地球科学科

affil-num=2
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学大学院自然科学研究科

affil-num=3
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学学術研究院自然科学学域

affil-num=4
en-affil=Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology
kn-affil=国立研究開発法人産業技術総合研究所 活断層・火山研究部門

affil-num=5
en-affil=Formerly Japan Agency for Marine-Earth Science and Technology
kn-affil=元・国立研究開発法人海洋研究開発機構

affil-num=6
en-affil=Department of Earth and Planetary Sciences, School of Science, Tokyo Institute of Technology
kn-affil=東京工業大学理学院地球惑星科学系
END

start-ver=1.4
cd-journal=joma
no-vol=29
cd-vols=
no-issue=1
article-no=
start-page=49
end-page=63
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=20230331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=Onset time and location of the main rupture of the 2018 Hokkaido Eastern Iburi, Japan, earthquake
kn-title=2018 年北海道胆振東部地震の初期の破壊過程
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=The rupture process at the beginning stage of the 2018 Hokkaido Eastern Iburi, Japan, earthquake (MJ 6.7) is investigated by analyzing P-wave records from local strong-motion stations. The records show about 3 s of small amplitude arrival (so-called "initial rupture phase") followed by the onset of the main energy release ("main rupture phase"). In this paper we address the issue: where the seismic energy release corresponding to the main rupture phase started at the primary stage of the main rupture, by locating the main rupture onset position. For this aim we applied the 2D and the 3D search methods to estimate the relative location of the onset of the main rupture with respect to the hypocenter, and the time difference between them. The 2D method assumes a plausible initial fault plane and locates the main rupture onset position on the initial fault plane, while the 3D method does not require such assumed fault planes. In the 2D method we employed each of the nodal planes of the first-motion focal mechanism as the initial rupture plane. The 3D method was able to give a better solution than the 2D one. It suggests that the main rupture initiation point might not be on the same fault plane as the hypocenter is. The solution shows that the main rupture onset point is 5.8 km southward and 2.5 km upward from the hypocenter, with the rupture time of 3.3 s from the origin time. It is consistent with the previous studies on the relationship between the magnitude and the initial rupture duration.
en-copyright=
kn-copyright=

en-aut-name=KOWARIHirofumi
en-aut-sei=KOWARI
en-aut-mei=Hirofumi
kn-aut-name=小割啓史
kn-aut-sei=小割
kn-aut-mei=啓史
aut-affil-num=1
ORCID=

en-aut-name=KOMATSUMasanao
en-aut-sei=KOMATSU
en-aut-mei=Masanao
kn-aut-name=小松正直
kn-aut-sei=小松
kn-aut-mei=正直
aut-affil-num=2
ORCID=

en-aut-name=TAKENAKAHiroshi
en-aut-sei=TAKENAKA
en-aut-mei=Hiroshi
kn-aut-name=竹中博士
kn-aut-sei=竹中
kn-aut-mei=博士
aut-affil-num=3
ORCID=

affil-num=1
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学大学院自然科学研究科

affil-num=2
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学大学院自然科学研究科

affil-num=3
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学学術研究院自然科学学域
en-keyword=2018 Hokkaido Eastern Iburi earthquake
kn-keyword=2018 Hokkaido Eastern Iburi earthquake
en-keyword=fault plane
kn-keyword=fault plane
en-keyword=initial rupture
kn-keyword=initial rupture
en-keyword=strong motion
kn-keyword=strong motion
END

start-ver=1.4
cd-journal=joma
no-vol=29
cd-vols=
no-issue=1
article-no=
start-page=29
end-page=48
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=20230331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=Summary of our activities toward development of the ESD interdisciplinary study plans on climate and cultural understanding education with attention to the seasonal cycle and “seasonal feeling” around Japan and Europe
kn-title=気候・文化理解教育の学際的ESD学習プラン開発へ向けた取り組み（日本とヨーロッパの季節サイクルや季節感に注目して）
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=We have continued the interdisciplinary integration of the knowledge on climate and music and have developed the crosscutting study plans on the climate and cultural understanding education. A part of these results had been summarized in a Japanese book titled “Climate and music (Cultural understanding and ESD spreading from the “Doors of Song”)” (Kato and Kato 2019), building mainly our papers written in Japanese. This article will re-integrate our above study results, mainly for the climate and songs/traditional seasonal events around Germany, Northern Europe and Japan, with special attention to (A) asymmetric seasonal progression from autumn to next spring around Japan, (B) winter climate around Germany in association with the seasonal feeling on the traditional events “Fasnacht” for driving winter away and (C) climate around Northern Europe in association with the seasonal feeling on the summer solstice festival “Juhannus” with comparison to the summer climate around Japan.
en-copyright=
kn-copyright=

en-aut-name=KATOKuranoshin
en-aut-sei=KATO
en-aut-mei=Kuranoshin
kn-aut-name=加藤内藏進
kn-aut-sei=加藤
kn-aut-mei=内藏進
aut-affil-num=1
ORCID=

en-aut-name=KATOHaruko
en-aut-sei=KATO
en-aut-mei=Haruko
kn-aut-name=加藤晴子
kn-aut-sei=加藤
kn-aut-mei=晴子
aut-affil-num=2
ORCID=

en-aut-name=AKAGIRikako
en-aut-sei=AKAGI
en-aut-mei=Rikako
kn-aut-name=赤木里香子
kn-aut-sei=赤木
kn-aut-mei=里香子
aut-affil-num=3
ORCID=

affil-num=1
en-affil=Faculty of Education, Okayama University
kn-affil=岡山大学学術研究院教育学域

affil-num=2
en-affil=Faculty of Education, Gufu Shotoku Gakuen University (Former Affiliation)
kn-affil=元 岐阜聖徳学園大学教育学部

affil-num=3
en-affil=Faculty of Education, Okayama University
kn-affil=岡山大学学術研究院教育学域
en-keyword=climate and music
kn-keyword=climate and music
en-keyword=interdisciplinary climate and cultural understanding education
kn-keyword=interdisciplinary climate and cultural understanding education
en-keyword=seasonal cycle around Japan and Europe
kn-keyword=seasonal cycle around Japan and Europe
en-keyword=seasonal feeling
kn-keyword=seasonal feeling
en-keyword=ESD
kn-keyword=ESD
en-keyword=comparative climatology
kn-keyword=comparative climatology
END

start-ver=1.4
cd-journal=joma
no-vol=29
cd-vols=
no-issue=1
article-no=
start-page=1
end-page=27
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=20230331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=Geology of the Paleogene to Neogene successions and gentle upwarping of the Kibi Plateau Surface, surrounding area of Kibichuou Town, Okayama Prefecture, Southwest Japan
kn-title=岡山県吉備中央町賀陽周辺の古第三系〜新第三系の地質と吉備高原面のゆるやかな曲隆
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=The Paleogene to Neogene successions which are composed of the Paleogene Kayo Formation, the late Oligocene to earliest Miocene Yagane Formation and the middle Miocene Ukan Formation are sporadically distributed in the Kibi Plateau region, surrounding area of Kibichuou Town, Okayama Prefecture, Southwest Japan. The gravel of the Kayo Formation occupied paleo-valley of Pre-Paleogene basement. The Yagane and Ukan formations unconformably overlay Pre-Paleogene rocks and occupy the gentle valley on the Kibi Surface as valley fill deposits.<br>
The fluvial of the Kayo Formation is mainly composed of conglomerate with minor amount of sandstone and mudstone. The fluvial Yagane Formation is mainly composed of conglomerate and associated with sandstone, mudstone and coal beds. The marine Ukan Formation is subdivided into 3 members, the Yamagata Muddy sandstone Member (YMM), the Shimoyokomi Sandstone Member (SSM) and the Tsuneyama Mudstone Member (TMM) in ascending order. The YMM is characterized by the bio-disturbed very poorly sorted muddy sandstone with frequent burrows, which indicate tidal flat deposits. The SSM is mainly composed of parallel bedded well-sorted sandstone with occasional burrows, which suggest near shore deposits. The TMM is composed of homogeneous clay rich mudstone, which implies off shore deposits.<br>
The boundary between the SSM and TMM (the contact of the sandstone and mudstone) is distinctive and correlative throughout the study area. The boundary is considered to be formed under similar water depth. The variations of the boundary height indicate a later ground movement. From the north to the south in about 25km distance, the height of the boundary changes 260m (in Ukan), 300m (in Takeshou), 360m (in Kibikogentoshi) and 260m (in Nichiouji). It indicates that a very gentle upwarping of the Kibi Plateau Surface was formed after the deposition of the Miocene.
en-copyright=
kn-copyright=

en-aut-name=TANAKAHajime
en-aut-sei=TANAKA
en-aut-mei=Hajime
kn-aut-name=田中元
kn-aut-sei=田中
kn-aut-mei=元
aut-affil-num=1
ORCID=

en-aut-name=SUZUKIShigeyuki
en-aut-sei=SUZUKI
en-aut-mei=Shigeyuki
kn-aut-name=鈴木茂之
kn-aut-sei=鈴木
kn-aut-mei=茂之
aut-affil-num=2
ORCID=

affil-num=1
en-affil=Seibu Engineering Consultants Co., Ltd.
kn-affil=西部技術コンサルタント株式会社

affil-num=2
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学理学部地球科学科
en-keyword=Kibi Plateau Surface
kn-keyword=Kibi Plateau Surface
en-keyword=Upwarping
kn-keyword=Upwarping
en-keyword=Miocene
kn-keyword=Miocene
en-keyword=Ukan Formation
kn-keyword=Ukan Formation
END

start-ver=1.4
cd-journal=joma
no-vol=29
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=20230331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Title Page
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=29
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2023
dt-pub=20230331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=表紙・英文目次
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=28
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2022
dt-pub=20220331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=裏表紙・目次
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=28
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2022
dt-pub=20220331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=岡山大学地球科学研究報告 投稿規定（約款）
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=28
cd-vols=
no-issue=1
article-no=
start-page=27
end-page=103
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2022
dt-pub=20220331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=FDM simulation of long-period ground motions around Oita Prefecture, Japan, using a land-ocean unified 3D structure model
kn-title=地形を考慮した陸海統合3次元地震波速度構造モデルを用いた大分県周辺の長周期地震動シミュレーション
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=Oita prefecture is located in northeastern part of Kyushu Island which is characterized by active subduction of the Philippine Sea plate (PHS) beneath the Eurasian plate and several active volcanoes along with the volcanic front. Oita area has frequently been damaged by large earthquakes and tsunamis since ancient times. From the point of view of disaster prevention, it is important to investigate the feasibility of strong ground motion prediction using realistic structural models. In this paper we use a land-ocean unified 3D (three-dimensional) structure model around Oita prefecture, which includes land and sea-floor topography and a seawater layer as well as subsurface structures of the arc side and the PHS slab to conduct the FDM (finite-difference method) simulations of strong ground motion in land and ocean areas for the 2015 Southern Oita, Japan, earthquake (MJMA5.7) whose hypocenter is located in the PHS slab. The simulated long-period (2?20 s) ground motions reproducing observed records demonstrate substantial contributions of thick low-velocity sediment layers in and around Beppu Bay and Oita basin to development of the motions. We also examine the topographic effects on the seismic motion by analyzing the simulation results to show the strong enhancement of the later phases.
en-copyright=
kn-copyright=

en-aut-name=OkunakaTatsuya 
en-aut-sei=Okunaka
en-aut-mei=Tatsuya 
kn-aut-name=奥仲達也
kn-aut-sei=奥仲
kn-aut-mei=達也
aut-affil-num=1
ORCID=

en-aut-name=KomatsuMasanao
en-aut-sei=Komatsu
en-aut-mei=Masanao
kn-aut-name=小松正直
kn-aut-sei=小松
kn-aut-mei=正直
aut-affil-num=2
ORCID=

en-aut-name=TakenakaHiroshi
en-aut-sei=Takenaka
en-aut-mei=Hiroshi
kn-aut-name=竹中博士
kn-aut-sei=竹中
kn-aut-mei=博士
aut-affil-num=3
ORCID=

en-aut-name=YoshimiMasayuki
en-aut-sei=Yoshimi
en-aut-mei=Masayuki
kn-aut-name=吉見雅行
kn-aut-sei=吉見
kn-aut-mei=雅行
aut-affil-num=4
ORCID=

en-aut-name=NakamuraTakeshi
en-aut-sei=Nakamura
en-aut-mei=Takeshi
kn-aut-name=中村武史
kn-aut-sei=中村
kn-aut-mei=武史
aut-affil-num=5
ORCID=

en-aut-name=OkamotoTaro
en-aut-sei=Okamoto
en-aut-mei=Taro
kn-aut-name=岡元太郎
kn-aut-sei=岡元
kn-aut-mei=太郎
aut-affil-num=6
ORCID=

affil-num=1
en-affil=Formerly Department of Earth Sciences, Okayama University
kn-affil=元・岡山大学理学部地球科学科

affil-num=2
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学大学院自然科学研究科

affil-num=3
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学学術研究院自然科学学域

affil-num=4
en-affil=Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology
kn-affil=国立研究開発法人産業技術総合研究所 活断層・火山研究部門

affil-num=5
en-affil=Formerly Japan Agency for Marine-Earth Science and Technology
kn-affil=元・国立研究開発法人海洋研究開発機構

affil-num=6
en-affil=Department of Earth and Planetary Sciences, School of Science, Tokyo Institute of Technology
kn-affil=東京工業大学理学院地球惑星科学系
en-keyword=strong motion
kn-keyword=strong motion
en-keyword=Oita
kn-keyword=Oita
en-keyword=the 2015 Southern Oita earthquake
kn-keyword=the 2015 Southern Oita earthquake
en-keyword=long-period ground motion
kn-keyword=long-period ground motion
en-keyword=simulation
kn-keyword=simulation
en-keyword=finite-difference method
kn-keyword=finite-difference method
en-keyword=topography
kn-keyword=topography
END

start-ver=1.4
cd-journal=joma
no-vol=28
cd-vols=
no-issue=1
article-no=
start-page=1
end-page=25
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2022
dt-pub=20220331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=Depositional history of the Paleogene to Neogene valley fill deposits and topographic change in the Kibi Plateau region, Okayama City, Southwest Japan
kn-title=岡山市北部吉備高原地域に分布する古第三系・新第三系の分布・堆積相と古地理変遷
en-subtitle=
kn-subtitle=
en-abstract=The deposition of the Paleogene to Neogene sediments in the Kibi Plateau region played an important role to form the Kibi Plateau Surface. Study area is situated in the southern part of the Kibi Plateau. Field work has been continued more than 30 years and traced distribution of the deposits which make clear the paleo-topography. Sedimentary facies of deposits were observed to understand depositional environments. Without Fission-Track zircon dating from tuff samples, we could not divide and define the formations. The Paleogene Kibi Group and the latest Paleogene to Neogene Bihoku Group are distributed in the study area. The Kibi Group is unusual deposits which filled steep valley in mountain area and comprise the Tomiyoshi Formation (36 to 34 Ma) and the Tsudaka Formation (29 to 27 Ma). The formations are fluvial deposits and have similar litho-facies. The distribution of the formations indicate drainage system when deposited. Conglomerates with imbricate structure are the major component of the formations and sandstones and mudstones (sometimes with plant fragments and rootlets) are associated. The Bihoku Group is composed of the fluvial Yagane Formation (24.5 to 25.5 Ma) and the shallow marine Nichiouji Formation (15 to 16 Ma). The formations have the same depositional basin of low relief valley. The Yagane Formation is composed of conglomerate, sandstone, mudstone and coaly mudstone. The Nichiouji Formation is composed of well sorted sandstone with marine fossils.
kn-abstract=
en-copyright=
kn-copyright=

en-aut-name=TanakaHajime
en-aut-sei=Tanaka
en-aut-mei=Hajime
kn-aut-name=田中元
kn-aut-sei=田中
kn-aut-mei=元
aut-affil-num=1
ORCID=

en-aut-name=SuzukiShigeyuki
en-aut-sei=Suzuki
en-aut-mei=Shigeyuki
kn-aut-name=鈴木茂之
kn-aut-sei=鈴木
kn-aut-mei=茂之
aut-affil-num=2
ORCID=

affil-num=1
en-affil=Seibu Engineering Consultants Co., Ltd.
kn-affil=西部技術コンサルタント株式会社

affil-num=2
en-affil=Department of Earth Sciences, Okayama University
kn-affil=岡山大学 特命教授・名誉教授
en-keyword=Kibi Plateau Surface
kn-keyword=Kibi Plateau Surface
en-keyword=Paleogene
kn-keyword=Paleogene
en-keyword=Kibi Group
kn-keyword=Kibi Group
en-keyword=Miocene
kn-keyword=Miocene
en-keyword=Bihoku Group
kn-keyword=Bihoku Group
END

start-ver=1.4
cd-journal=joma
no-vol=28
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2022
dt-pub=20220331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=Title Page
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END

start-ver=1.4
cd-journal=joma
no-vol=28
cd-vols=
no-issue=1
article-no=
start-page=
end-page=
dt-received=
dt-revised=
dt-accepted=
dt-pub-year=2022
dt-pub=20220331
dt-online=
en-article=
kn-article=
en-subject=
kn-subject=
en-title=
kn-title=表紙・英文目次
en-subtitle=
kn-subtitle=
en-abstract=
kn-abstract=
en-copyright=
kn-copyright=
END