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JaLCDOI 10.18926/ESR/13907
Title Alternative Chemical and Rb-Sr isotopic features of the shock-melted chondrite Yamato-793533
FullText URL ESR_6_29.pdf
Author Okano, Osamu| Katayama, Hiroko| Nakamura, Noboru|
Abstract The Sr isotopic compositions and Rb and Sr abundances, as well as major element abundances in olivine, pyroxenes and glass, were determined for a chip and 21 fractions separated from a shock-melted chondrite Yamato-793533, a dark-colored, porous stone with glassy texture. Two lithologies were recognized for the 1.5g specimen studied (Yamato-793533, 67) ; L (Main portion) and L to LL (Dark portion) chondritic in terms of chemical compositions of olivine and pyroxenes. The chemical compositions of glass are relatively homogeneous (SiO2=67-77%) compared to those of other ordinary chondrites, suggesting a moderate cooling rate after shock-melting. The data points for fractions do not foem any isochron in a 87Rb/86Sr vs. 87Sr/86Sr diagram. However, it is noted that six out of nine points for the dark portion plot around a 1.2 Ga line, while most of points for the main portion plot around a 4.55 Ga chondrite isochron. The observed difference could be responsible for difference in melting degrees between the two portions. Similar Rb-Sr features have been found among shock-melted Yamato-79 LL-chondrites which are considered to be paired stones experienced the same shock-melting event at 1.2 Ga. Consequently, the Rb-Sr systematics as well as petrologic features strongly suggest that Yamato-793533 is a member of a series of the shock-melted Yamato-79 LL-chondrites.
Keywords LL-chondrite Shock-melting Sr isotope
Publication Title Okayama University Earth Science Report
Published Date 1999-09-20
Volume volume6
Issue issue1
Start Page 29
End Page 38
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 120002310391
JaLCDOI 10.18926/ESR/13906
Title Alternative Peat bed of Jomon age in Desaki Beach, Tamano City, Okayama Prefecture
FullText URL ESR_6_23.pdf
Author Suzuki, Shigeyuki| Yukimoto, Koichi|
Abstract Peat bed remains isolated in the shoreline of western beach of Desaki peninsula. Collected samples gave radiocarbon data of 5790±80 and 5810±60 years BP.
Keywords Peat Holocene Desaki Beach
Publication Title Okayama University Earth Science Report
Published Date 1999-09-20
Volume volume6
Issue issue1
Start Page 23
End Page 28
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 120002310593
JaLCDOI 10.18926/ESR/13905
Title Alternative Measurements of CO2 in air and sea over the Western Pacific-MR98-04 Cruise-
FullText URL ESR_6_13.pdf
Author Kono, Takehiko| Yamashita, Eiji| Nogami, Terumasa| Tsukamoto, Osamu|
Abstract It is well known that the ocean plays a very important role in the overall geochemical cycle of CO2. Over the ocean surface, CO2 is equilibrated between partial pressure of CO2 in the seawater (pCO2) and that in the atmosphere(PCO2). The objectives of the present observation are to evaluate the following : (1) Horizontal distribution of pCO2 and PCO2, (2) Sea surface CO2 flux and (3) Vertical distribution of pCO2.
Keywords Western Pacific pCO2 PCO2 Horizontal distribution CO2 flux Vertical distribution
Publication Title Okayama University Earth Science Report
Published Date 1999-09-20
Volume volume6
Issue issue1
Start Page 13
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 120002310525
JaLCDOI 10.18926/ESR/13902
FullText URL ESR_7_47.pdf
Author Yamagiwa Nobuo| Suzuki, Shigeyuki| Okimura Yuji|
Abstract A new rugose coral species, Lithostrotion (Siphonodendron) hinensis is described in this paper. It was collected from the Carboniferous Hina limestone in Okayama Prefecture, Southwest Japan. Judging from the paleontological data, the age indicates probably Late Viaean, Early Carboniferous.
Keywords Early Carboniferous rugosa Lithostrotion (Siphonodendron) Hina Limestone Okayama
Publication Title Okayama University Earth Science Report
Published Date 2000-09-20
Volume volume7
Issue issue1
Start Page 47
End Page 50
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 120002310319
JaLCDOI 10.18926/ESR/13901
Title Alternative Tidal notch cut into the Namigata Limestone, 240m above sea level, Ibara City, Okayama Prefecture
FullText URL ESR_7_41.pdf
Author Fujiwara, Takao| Suzuki, Shigeyuki| Maeda, Yasuo|
Abstract The tidal notch and the sea caves which cut into the Namigata Limestone is stiuated in 240m above sea level, Ibara City. The notch assocciates the Namigata Terrace 200m to 240m high. These geomorphological features indicate an event of high sea level. However the age of the event has not been known.
Keywords notch sea cave Namigata Okayama Prefecture
Publication Title Okayama University Earth Science Report
Published Date 2000-09-20
Volume volume7
Issue issue1
Start Page 41
End Page 46
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 120002310395
JaLCDOI 10.18926/ESR/13900
Title Alternative Relashonships between "Mountation Gravels" and the Bizen and Tomihara Coal Measures, northern Okayama City, Southwest Japan
FullText URL ESR_7_35.pdf
Author Suzuki, Shigeyuki| Nakazawa, Keiji| Tanaka, Hajime|
Abstract The Bizen and Tomihara Coalfields which were situated in northern Okayama City, had produced lignite during 1940s. Distribution of coal measures indicates that the coal measures are intercalated in the middle of the so-called "Mountain Gravels". The "Mountain Gravels" is subdivided into two formations ; the older, about 34~35Ma, and the younger, about 27Ma, of fission track ages. The older formation inculudes the Bizen Coal Measures. On the other hand, the Tomihara Coal Measures are intercalated in the younger formation.
Keywords Bizen Coal Measures Tomihara Coal Measures Okayama City Paleogene
Publication Title Okayama University Earth Science Report
Published Date 2000-09-20
Volume volume7
Issue issue1
Start Page 35
End Page 40
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 120002310497
Author Joichi, Yasutaka| Narong, Lenghor| Takayanagi, Toshio| Oshima, Mitsuko| Motomizu, Shoji| Ura, Nobuo|
Published Date 2006-11-17
Publication Title 分析化学
Volume volume55
Issue issue9
Content Type Journal Article
JaLCDOI 10.18926/ESR/13894
Title Alternative Native gold from Mikawa mine, Niigata Prefecture, Japan
FullText URL ESR_7_19.pdf
Author Yamakawa, Junji| Tanabe, Mitsuo| Shimada, Kazumasa| Henmi, Chiyoko|
Abstract Native gold was found at Mikawa mine, Niigata Prefecture, Japan. The mineral was associated with quartz in a druse within quartz-vein in propyrite. The crystals were formed in filiform, reticulated and dendritic shapes with about 1 mm length with 0.1 mm width and 0.05 mm thickness. Very malleable and ductile, opaque and yellow with metallic luster. Qualitative and semi-quantiative analyses were performed by the wavelength dispersive EPMA. Quantitatively, the crystals contained Au, Ag and Hg. Semi-quantitative analyses were executed with ZAF correction algorithm. The results showed that these specimens had a average chemical composition Au0.77 Ag0.11Hg0.12. This specimen was archived at our site with a collection number ESO-M01001.
Keywords Native Gold Mikawa Mine electrum ESO-M01001
Publication Title Okayama University Earth Science Report
Published Date 2000-09-20
Volume volume7
Issue issue1
Start Page 19
End Page 20
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 120002310280
JaLCDOI 10.18926/ESR/13891
Title Alternative Automated observation of sea surface eddy flux on a cruising ship
FullText URL ESR_7_1.pdf
Author Takahashi, Satoshi| Tsukamoto, Osamu| Ishida, Hiroshi| Yoneyama, Kunio|
Abstract Sea surface eddy fluxes were evaluated with the eddy correlation method including ship motion correction for the wind vector components. Previous ship motion correction algorithm was revised as a simple scheme setting a motion sensor at the same place with the sonic anemometer. This revised eddy flux system was mounted as a routine continuous measurement system on the R/V 'Mirai' of Japan Marine Science and Technology Center. The first cruise was conducted at the tropical weatern Pacific in June 2000. Continuous sea surface fluxes were obtained and the data quality was checked with some parameters. This system is planned to be developed as a automated data processing system including ship motion correction and real-time flux evaluation system. These eddy fluxes can be integrated with the bulk fluxes and radiation fluxes to understand sea surface heat balance over the global ocean.
Keywords Sea surface fliux Automated observation Eddy correlation method
Publication Title Okayama University Earth Science Report
Published Date 2000-09-20
Volume volume7
Issue issue1
Start Page 1
End Page 14
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 120002310644
Author Yamamoto, Takako| Akhmad, Sabarudin| Noguchi, Osamu| Takayanagi, Toshio| Oshima, Mitsuko| Motomizu, Shoji|
Published Date 2006-11-17
Publication Title 分析化学
Volume volume55
Issue issue9
Content Type Journal Article
JaLCDOI 10.18926/ESR/13887
Title Alternative Trace of the Median Tectonic Line in Mima area, eastern Shikoku
FullText URL ESR_8_1_13.pdf
Author Mizui, Yoshinobu| Tachibana, Toru| Suzuki, shigeyuki|
Abstract Tracing outcrops of shear zone were used to describe the geometry and structure of the Median Tectonic Line in Mima area, eastrn Shikoku. A distinct new fault outcrop was discovered between the Mino and Ikuchi Faults at the northern slope of the Mt. Boso. These two faults are regarded as a single continuous fault. The analysis of surface fabrics of quartz in fault in fault gauge has been carried out to determine relative fault activity events.
Keywords surface fabrics fault gauge Mino-Ikuchi Fault Median Tectonic Line
Publication Title Okayama University Earth Science Report
Published Date 2001-09-20
Volume volume8
Issue issue1
Start Page 13
End Page 28
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 120002310656
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/13863
Title Alternative Increase Rate of fCO2 in the Eastern Equatorial Pacific Ocean
FullText URL earth_science_reports_011_1_15.pdf
Author Kondo, Fumiyoshi| Tsukamoto, Osamu| Watanabe, Shuichi|
Abstract In the Eastern Equatorial Pacific Ocean, increase rates of fCO2 in the air and the ocean were evaluated using the CDIAC data set. The fCO2 in the air was increasing about 1.28μatm/year during 1957-1995. This result is almost same as the rate at the Mauna Loa, Hawaii in Tropical Pacific Ocean. The increase rate of fCO2 in the seawater was estimated as 1.64μatm/year. In this study it is found that the increase rate of fCO2 in the seawater is the almost same as that of fCO2 in the air. This reault supports the result on the snapshot analysis of Takahashi et al. (1983) in thr North Atlantic Ocean during 1958-1982. It is smaller than the result including seasonal variation in the Eastern Subtropical Pacific Ocean. These reault indicated that the anthropogenic CO2 in the air has affected fCO2 in seawater through CO2 gas exchange between the atmosphere and the ocean. It is found that fCO2 in the seawater has increased in the Eastern Equatiorial Pacific Ocean in spite of the large CO2 source region. It suggested that CO2 source potential has not changed in this ocean durung 1957-1995.
Keywords fCO2 Increase Rate Eastern Equatorial Pacific Ocean E1 Nino La Nina
Publication Title Okayama University Earth Science Report
Published Date 2004-12-31
Volume volume11
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 120002310498
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