Faculty Profiles - MINAMI, Masayo

Papers - MINAMI, Masayo

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Syngenetic rapid growth of ellipsoidal silica concretions with bitumen cores Reviewed International coauthorship

Yoshida Hidekazu, Kuma Ryusei, Hasegawa Hitoshi, Katsuta Nagayoshi, Sirono Sin-iti, Minami Masayo, Nishimoto Shoji, Takagi Natsuko, Kadowaki Seiji, Metcalfe Richard

SCIENTIFIC REPORTS Vol. 11 ( 1 ) page： 4230 2021.2

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Scientific Reports

Isolated silica concretions in calcareous sediments have unique shapes and distinct sharp boundaries and are considered to form by diagenesis of biogenic siliceous grains. However, the details and rates of syngenetic formation of these spherical concretions are still not fully clear. Here we present a model for concretion growth by diffusion, with chemical buffering involving decomposition of organic matter leading to a pH change in the pore-water and preservation of residual bitumen cores in the concretions. The model is compatible with some pervasive silica precipitation. Based on the observed elemental distributions, C, N, S, bulk carbon isotope and carbon preference index (CPI) measurements of the silica-enriched concretions, bitumen cores and surrounding calcareous rocks, the rate of diffusive concretion growth during early diagenesis is shown using a diffusion-growth diagram. This approach reveals that ellipsoidal SiO2 concretions with a diameter of a few cm formed rapidly and the precipitated silica preserved the bitumen cores. Our work provides a generalized chemical buffering model involving organic matter that can explain the rapid syngenetic growth of other types of silica accumulation in calcareous sediments.

DOI： 10.1038/s41598-021-83651-w

Web of Science

Scopus

PubMed

Characteristics in Trace Elements Compositions of tephras (B-Tm and To-a) for Identification tools Reviewed

Fumiko Watanabe Nara, Tatsunori Yokoyama, Shin-Ichi Yamasak, Masayo Minam, Yoshihiro Asahara, Takahiro Watanabe, Kazuyoshi Yamada, Noriyoshi Tsuchiya, Yoshinori Yasuda

Geochemical Journal Vol. 55 ( 3 ) page： 117 - 133 2021

Language：English Publishing type：Research paper (scientific journal) Publisher：GEOCHEMICAL SOC JAPAN

The absolute date of the Millennium Eruption (ME) of Changbaishan Volcano is widely recognized as AD 946. The Baegdusan-Tomakomai (B-Tm) tephra dispersed during the ME is a robust-age key bed. In order to identify the tephra, refractive index and major- element compositions of volcanic glass shards are conventionally used. Meanwhile, traceelement analysis using the inductively coupled plasma mass spectrometry (ICP- MS) technique for the volcanic glass shards and bulk samples of the B- Tm tephra is still limited. Here we give a detailed description of major- and traceelement compositions for the glass shards and bulk sediments of the B-Tm and Towada caldera eruptions (To-a) tephra deposits from the Lake Ogawara sediment core, Tohoku region, northern Japan to identify the tephras. The depth profiles of the major and trace elements show the significant peaks for the K2O and some trace elements (Zn, Rb, Zr, Nb, Sn, Y, La, Ce, Nd, Th, and U) at the B-Tm tephra layer in the Lake Ogawara sediment core, but no peaks of these elements at the Toa tephra layer. High concentrations of the trace elements in the B- Tm tephra layer were observed in individual glass shards as well as in the bulk sediment. These concentrations are highlighted by the elemental abundance pattern normalized by the crustal abundance. The elemental pattern in individual glass shards from other Japanese tephras showed significant differences from those of the B-Tm tephra, especially in REE compositions. The trace-element compositions of the glass shards and bulk sediments show a strong tool for distinguishing the B-Tm tephra from other Japanese tephras.

DOI： 10.2343/geochemj.2.0619

Web of Science

Scopus

火葬骨・木炭の放射性炭素年代測定

南雅代

松原市立部遺跡発掘調査報告書 Vol. ー page： 68 - 72 2021

人骨のストロンチウム同位体分析

若木重行, 南雅代

松原市立部遺跡発掘調査報告書 Vol. ー page： 73 - 77 2021

土壌資料のストロンチウム同位体分析

若木重行, 南雅代

松原市立部遺跡発掘調査報告書 Vol. ー page： 78 - 80 2021

Sequential magma injection with a wide range of mixing and mingling in Late Jurassic plutons, southern Ghorveh, western Iran Reviewed International coauthorship

Azizi Hossein, Asahara Yoshihiro, Minami Masayo, Anma Ryo

JOURNAL OF ASIAN EARTH SCIENCES Vol. 200 2020.9

Language：Japanese Publisher：Journal of Asian Earth Sciences

Intrusive bodies with a wide-ranging geology are distributed in the central part of the Sanandaj-Sirjan zone (C–SaSZ) in southern Ghorveh, western Iran. The zircon U–Pb ages were dated at 154–146 Ma, and were characterized by low 87Sr/87Sr(i) ratios and high 143Nd/144Nd(i) ratios that ranged from 0.7035 to 0.7061 and 0.51245 to 0.51271, respectively (positive εNd(t) values). Magma differentiation and mixing formed different magmatic rocks that range widely from gabbro to granite in the Meiham–Shirvaneh area in southern Ghorveh. However, there was no clear evidence to support the slab role for the enrichment of large-ion lithophile elements (LILEs) and light rare–earth elements (LREEs) in this area. Meanwhile, there is a possibility that some ocean island basalt-like melt, which has been reported in the Ghorveh area for the same period, was involved in the minor enrichment of LILEs and LREEs. The high development of the released depleted mantle melts, with a minor role played by crustal components, accelerated the thinning of the continental crust in an extensional regime such as continental rift in the C–SaSZ during the Jurassic. This rift was responsible for the sequential injection of mafic magma with a wide range of magma mixing and mingling in southern Ghorveh during the Late Jurassic. As a result, we observed a wide range of intrusive rocks from gabbro to granite with different compositions, which included some clear mixing and hybrid textures. This finding demonstrated how the released mantle melt formed a thicker crust in western Iran.

DOI： 10.1016/j.jseaes.2020.104469

Web of Science

Scopus

Variability of protoliths and pressure-temperature conditions of amphibolites from the Ohmachi Seamount (Izu-Bonin-Mariana arc): Evidence of a fossil subduction channel in modern intra-oceanic arcs Reviewed

Imayama, T, Ueda, H, Usuki, T, Minami, M, Asahara, Y, Nagahashi, T

Mineralogy and Petrology Vol. 114 ( 4 ) page： 305 - 318 2020.8

Rapid formation of gigantic spherical dolomite concretion in marine sediments Reviewed

Yusuke Muramiya, Hidekazu Yoshida, Kaoru Kubota, Masayo Minami

Sedimentary Geology Vol. 404 page： 105664 - 105664 2020.7

巨石のSr同位体比と埋没木片の14C年代からみた前橋泥流. Reviewed

南雅代

群馬県立自然史博物館研究報告 Vol. 24 page： 31 - 42 2020.6

榛名・小野子・子持火山の基盤を構成する火山岩類の岩石化学的特徴：天然記念物「岩神の飛石」との比較 Reviewed

佐藤興平・南雅代

群馬県立自然史博物館研究報告 Vol. 24 page： 43 - 52 2020.3

関東山地北西縁の下仁田地域に産する南蛇井層：ジルコンのU−Pb年代による予察 Invited Reviewed

佐藤興平・竹内　誠・李　雨嘯・南　雅代・柴田　賢

群馬県立自然史博物館研究報告 Vol. 24 page： 53 - 70 2020.3

Investigation of rare earth elements (REEs) as exploration potential in Intrusive bodies in the northern Sanandaj-Sirjan zone (Kurdistan area), western Iran International coauthorship

Azizi Hossein, Maghsoudloo Ali, Nouri Fatemeh, Asahara Yoshihiro, Yamamoto Koshi, Minami Masayo, Tsuboi Motohiro

GEOCHEMICAL JOURNAL Vol. 54 ( 4 ) page： 221 - 232 2020

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：GEOCHEMICAL SOCIETY OF JAPAN

Various granitoid bodies from the Neoproterozoic to Late Cenozoic intruded in the Sanandaj-Sirjan zone (SaSZ) in western Iran. In this research, we have compiled data for rare earth elements (REEs) concentration in the granitoid bodies which we have collected in the northern part of the SaSZ in this decade. The abundances of ∑REEs in a part of the granitoids are over 500 and even 2000 ppm. Although most of the granitoids such as Ebrahim Atar, Panjeh, Ghorveh, Kangareh, and Ghalaylan have low or normal values of ∑REEs and are not hopeful for future exploration, some hopeful bodies such as the Mobarak Abad granitoid in the east of Sanandaj and the Hassansalaran A-type granites in the east of Saqqez are recognized as REEs potential for future exploration. The chemical compositions of the REEs-enriched granites such as the Hassansalaran A-type and Mobarak Abad granites infer that the granites were generated in an extensional tectonic regime. Our finding shows that the granitic rocks which are related to the within plate tectonic setting in the SaSZ, NW Iran, can be considered as good potential for REEs exploration in the future.

DOI： 10.2343/geochemj.2.0584

Web of Science

Scopus

CiNii Research

Radiocarbon dating of cremated bones from the Ishibotoke-dani of Binman-ji Temple in Taga, Shiga Prefecture, Japan: A preliminary report. International coauthorship

南雅代

Proceedings of EA-AMS 8 & JAMS-22 Vol. - page： 94 - 97 2020

New procedure of CO2 extraction for radiocarbon analysis of DIC in water samples at Nagoya University and Geological Survey of Japan. International coauthorship

南雅代

Proceedings of EA-AMS 8 & JAMS-22 Vol. - page： 60 - 63 2020

イラン北西部アリ・サドル洞窟のつらら石のU/Th年代, 14C年代, 炭素・酸素安定同位体比

堀川恵司, 南雅代, 安間了

都市文明の本質：古代西アジアにおける都市の発生と変容の学際研究研究成果報告2019年度 Vol. 1 page： 187 - 195 2020

A SUITABLE PROCEDURE FOR PREPARING OF WATER SAMPLES USED IN RADIOCARBON INTERCOMPARISON Reviewed

Takahashi H. A, Minami M, Aramaki T, Handa H, Saito-Kokubu Y, Itoh S, Kumamoto Y

RADIOCARBON Vol. 61 ( 6 ) page： 1879 - 1887 2019.12

RADIOCARBON DATING OF TEXTILE COMPONENTS FROM HISTORICAL SILK COSTUMES AND OTHER CLOTH PRODUCTS IN THE RYUKYU ISLANDS, JAPAN

Nakamura Toshio, Terada Takako, Ueki Chikako, Minami Masayo

RADIOCARBON Vol. 61 ( 6 ) page： 1663 - 1674 2019.12

EFFECT OF CRYSTALLINITY OF APATITE IN CREMATED BONE ON CARBON EXCHANGES DURING BURIAL AND RELIABILITY OF RADIOCARBON DATING

Minami M, Mukumoto H, Wakaki S, Nakamura T

RADIOCARBON Vol. 61 ( 6 ) page： 1823 - 1834 2019.12

Radiocarbon changes of unpoisoned water samples during long-term storage Reviewed

Takahashi Hiroshi A, Minami Masayo, Aramaki Takafumi, Handa Hiroko, Matsushita Makoto

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS Vol. 455 page： 195 - 200 2019.9

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：ELSEVIER

The preservation of unpoisoned water samples was investigated by radiocarbon analysis with five kinds of natural waters. Although refrigerated and shielded from light, the unpoisoned samples underwent carbon isotopic changes, even after short periods of storage (e.g., 5 days). Examinations of the isotopic changes during long-term preservation (580 or 860 days) revealed C-14 increases to be approximate 10 pMC and delta C-13 decreases to be - 5.4 parts per thousand. Performance tests on the sample bottles suggested that PAN (polyacrylonitrile) and glass were suitable materials for long-term preservation.

DOI： 10.1016/j.nimb.2018.11.029

Web of Science

Scopus

Retentive primary Sr isotopic ratio of source rock to sediment and sedimentary rock through multistage sedimentary cycles: Case study of stream sediments in Awajishima Island Reviewed

Ohta Atsuyuki, Minami Masayo

Chikyukagaku Vol. 53 ( 2 ) page： 59 - 70 2019.6

Language：Japanese Publisher：The Geochemical Society of Japan

We have elucidated retention of primary Sr isotopic ratios in source rocks to sediments and sedimentary rocks during repeated sedimentation recycling. Twenty-three fine stream sediments (<180 μm) in Awajishima Island were used for the study. The 87Rb/86Sr and 87Sr/86Sr of stream sediments originated from Cretaceous Ryoke granitic rocks and Cretaceous sedimentary rocks (Izumi Group) were similar to those of the respective source rocks. Incidentally, the 87Rb/86Sr-87Sr/86Sr of stream sediments in Awajishima Island suggests that Cretaceous felsic igneous rocks are the dominant source of clastics in Izumi Group. Stream sediments derived from Neogene and Quaternary sediments, which are originated from granitic rocks and Izumi Group, had comparable isotopic ratios to those of the respective primitive source rocks. Accordingly, 87Rb/86Sr and 87Sr/86Sr can be retained during the repeated recycling process of sediments and sedimentary rocks. Stream sediment is presumed to consist of clastics supplied from respective lithologies according to their exposed areas. However, 87Sr/86Sr of stream sediment is not comparable to the values calculated from exposed areas of lithologies and isotopic data of parent rocks. The result suggests that amount of sedimentation denudation and production differs among different lithologies and is not simply proportional to their exposed areas.

DOI： 10.14934/chikyukagaku.53.59

CiNii Research

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Papers - MINAMI, Masayo