著者
椋本 ひかり 南 雅代 若木 重行 中村 俊夫 Mukumoto Hikari Minami Masayo Wakaki Shigeyuki Nakamura Toshio
出版者
名古屋大学宇宙地球環境研究所年代測定研究部
雑誌
名古屋大学年代測定研究
巻号頁・発行日
no.1, pp.102-107, 2017-03-31

Bones exposed to temperatures of more than 600℃ become to possess the high crystallinity of apatite, which protects them against easy contamination. This property now makes it possible to use the carbonate hydroxyapatite (CHa), an inorganic component of bone, for the 14C dating of cremated bones. Other chemical characteristics, such as Sr/Ca and δ88Sr, indicators of trophic levels and/or dietary preferences, are also expected to be preserved in cremated bones. This study was conducted to examine whether the CHa in cremated bones can provide accurate 14C dates and reliable information on diet. Cremated bone fragments from an urn at the Jisho-in Temple in Nara Prefecture, Japan were used as the sample. These bones are thought to be the remains of Jokei, a Buddhist monk (AD 1155–1213). The CHa in two fragments, which have high crystallinity, was determined to have a 14C date of 1040–1220 cal AD (±2σ), a date similar with the presumed age. The log(Sr/Ca) and δ88Sr values obtained from the bone CHa were –2.79 and from –0.140 to –0.125, respectively, values similar to those of herbivores (log(Sr/Ca)= –3.0~–2.5; Balter et al., 2002, δ88Sr =–0.30±0.17‰; Tütken et al., 2015). This finding is consistent with Jokei's dietary custom of not eating meat. The results of this study demonstrate the effectiveness of using CHa in cremated bones for the 14C dating of bones and dietary analysis.最近の研究により、火葬されて有機成分が残存していない骨に対し、骨の無機成分である炭酸ヒドロキシアパタイト(Carbonate Hydroxyapatite: CHa)を用いた14C年代測定の有効性が実証された(Lanting et al., 2001; Zazzo et al., 2011)。CHaは、高温(>600℃)で加熱されると結晶化が進み埋没後に続成作用の影響を受けにくくなることがその理由として挙げられる。そのため、結晶性の高いCHaを含む火葬骨は、生体由来の化学成分を保持でき、栄養段階の指標であるSr/Ca値やδ88Sr値などを分析することにより、14C年代だけでなく食性に関する情報も復元できることが期待できる。そこで、本研究では、仏教徒「貞慶」(AD1155-1213)の遺骨とされる火葬骨のSr/Ca値及びδ88Sr値の分析を行い、貞慶が菜食であったことを実証できるかどうかを検討した。結晶性の高い火葬骨のCHaから得られた14C年代値は貞慶の没年(1213年)と矛盾しない結果であった。さらに、log(Sr/Ca)値は-2.79、δ88Sr値は-0.14~-0.13であり、いずれも草食動物の値(log(Sr/Ca)=-3.0~-2.5; Balter et al., 2002、δ88Sr値=-0.47~-0.13; Tütken et al., 2015))の範囲であった。この結果は、貞慶が菜食主義であったことを示すものであり、考古学的な見解と一致している。これらの結果から、高温で加熱され、結晶性が高い火葬骨CHaは、生体由来のSr/Ca値及びδ88Sr値を保持しており、年代に関する情報だけでなく生前の食習慣を探るのにも有効であることが明らかになった。本研究は、日本学術振興会科学研究費補助金挑戦的萌芽研究[骨の炭酸ヒドロキシアパタイトを用いた炭素14年代測定の試み」(代表者:南雅代、課題番号26560144)の助成を受けて行なわれました。
著者
太田 充恒 南 雅代
出版者
一般社団法人日本地球化学会
雑誌
地球化学 (ISSN:03864073)
巻号頁・発行日
vol.53, no.2, pp.59-70, 2019-06-25 (Released:2019-06-25)
参考文献数
31

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.
著者
南 雅代 Minami Masayo 中村 俊夫 Nakamura Toshio 平田 和明 Hirata Kazuaki 長岡 朋人 Nagaoka Tomohito 鵜澤 和宏 Hoshino Keigo
出版者
名古屋大学年代測定資料研究センター
雑誌
名古屋大学加速器質量分析計業績報告書
巻号頁・発行日
vol.18, pp.134-143, 2007-03

During the past several decades, many medieval skeletons were excavated from archaeological sites in the Yuigahama area, Kamakura, Japan. The excavations yielded more than 5,000 individuals in varying states of preservation from the Zaimokuza, Seiyokan, Yuigahama-minami and Chusei Shudan Bochi sites. Medieval Kamakura was an ancient capital of the Kamakura Shogunate, and a lot of people lived in Kamakura with high population density. The human skeletons excavated from the Zaimokuza site are reported to be humans dead by competition at the end of the Kamakura Shogunate, but a detailed study on dating of the human skeletons has not made yet. In this study, we measured ^<14>C ages, together with carbon and nitrogen isotope ratios, of human skeletal remains excavated from the Yuigahama-minami site and Chusei Shudan Bochi site. The δ^<13>C and δ^<15>N were not different between human skeletal samples of both sites, while the ^<14>C ages were different between them: The human bones of the Yuigahama-minami site are 100 year younger than those of the medieval collective-cemetery site. All of ages of human skeletons from both of the sites are older than the latest Kamakura period. The δ^<13>C and δ^<15>N values of the medieval Kamakura people are higher than those of terrestrial mammals, indicating that they exploited some amount of marine fish and/or mammals with higher δ^<13>C and δ^<15>N as protein sources. Therefore, the ^<14>C ages obtained for human skeletons could be order than the true ages. ^<87>Sr/^<86>Sr isotopic ratios of human skeletons of the Yuigahama-minami site tend to be higher than those of the Chusei Shudan Bochi site. Soils, plants and animals feeding on them in a given locality have ^<87>Sr/^<86>Sr values that generally mirror underlying bedrock composition, and thus ^<87>Sr/^<86>Sr ratios of human skeletons are useful tools for assessing migration in prehistory. The result obtained in this study suggests that Yuigahama-minami humans and Chusei Shudan Bochi humas lived in different areas. More skeleton samples should be analyzed for determining detailed ^<14>C ages of humans excavated from the Yuigahama sites, and for estimating migration of prehistory of the medieval Kamakura humans.
著者
南 雅代 鈴木 和博 中村 俊夫 池田 晃子
出版者
一般社団法人日本地球化学会
雑誌
日本地球化学会年会要旨集
巻号頁・発行日
vol.61, 2014

キツネは50年ほど前まで里山の至る所に生息していた最もポピュラーな野生動物であり、愛知県豊田市の市街地から北東に約17 km離れた山間集落である小手沢にも、1960年代初めまでは多くのキツネが生息していた。しかし、キツネは1960年代後半から次第にいなくなり、現在では全く目撃されなくなっている。そこで、本研究では、小手沢集落の旧地蔵堂の解体(2010年1月17日)中に床下から見つかったキツネ遺骸の歯および骨の14C濃度から、それぞれ誕生および死亡年代を求め、キツネが里山から消えた時期を明らかにすることを目的とした。このキツネの遺骸の脇には1971-1983年版のチキンラーメンの袋が見つかっていることから、キツネが消えた時期を解明する鍵になると推察された。本発表においては、14C年代測定の他、C・N・Srの安定同位体比の測定も行ない、キツネの食性を推定することにより、キツネが里山から消えた原因も考察する。
著者
南 雅代 Minami Masayo 中村 俊夫 Nakamura Toshio 平田 和明 Hirata Kazuaki 長岡 朋人 Nagaoka Tomohito 鵜澤 和宏 Hoshino Keigo
出版者
名古屋大学年代測定資料研究センター
雑誌
名古屋大学加速器質量分析計業績報告書
巻号頁・発行日
vol.18, pp.134-143, 2007-03 (Released:2010-06-10)

During the past several decades, many medieval skeletons were excavated from archaeological sites in the Yuigahama area, Kamakura, Japan. The excavations yielded more than 5,000 individuals in varying states of preservation from the Zaimokuza, Seiyokan, Yuigahama-minami and Chusei Shudan Bochi sites. Medieval Kamakura was an ancient capital of the Kamakura Shogunate, and a lot of people lived in Kamakura with high population density. The human skeletons excavated from the Zaimokuza site are reported to be humans dead by competition at the end of the Kamakura Shogunate, but a detailed study on dating of the human skeletons has not made yet. In this study, we measured ^<14>C ages, together with carbon and nitrogen isotope ratios, of human skeletal remains excavated from the Yuigahama-minami site and Chusei Shudan Bochi site. The δ^<13>C and δ^<15>N were not different between human skeletal samples of both sites, while the ^<14>C ages were different between them: The human bones of the Yuigahama-minami site are 100 year younger than those of the medieval collective-cemetery site. All of ages of human skeletons from both of the sites are older than the latest Kamakura period. The δ^<13>C and δ^<15>N values of the medieval Kamakura people are higher than those of terrestrial mammals, indicating that they exploited some amount of marine fish and/or mammals with higher δ^<13>C and δ^<15>N as protein sources. Therefore, the ^<14>C ages obtained for human skeletons could be order than the true ages. ^<87>Sr/^<86>Sr isotopic ratios of human skeletons of the Yuigahama-minami site tend to be higher than those of the Chusei Shudan Bochi site. Soils, plants and animals feeding on them in a given locality have ^<87>Sr/^<86>Sr values that generally mirror underlying bedrock composition, and thus ^<87>Sr/^<86>Sr ratios of human skeletons are useful tools for assessing migration in prehistory. The result obtained in this study suggests that Yuigahama-minami humans and Chusei Shudan Bochi humas lived in different areas. More skeleton samples should be analyzed for determining detailed ^<14>C ages of humans excavated from the Yuigahama sites, and for estimating migration of prehistory of the medieval Kamakura humans.
著者
鈴木 和博 南 雅代 加藤 丈典
出版者
名古屋大学
雑誌
基盤研究(B)
巻号頁・発行日
2007

・電子プローブマイクロアナライザを高性能・高機能化して分析値の精度と確度を高めた.・トリウムやウランを含む鉱物のコンコーダントな分析値を選別する化学的基準を確立して、CHIME年代の確度を高くした.・氷上花簡岩、領家帯ミグマタイト、肥後変成岩、韓国京畿地塊の準片麻岩、中国南東部の花商岩類、中国吉林省の東清花簡岩のCHIME年代を再検討して、地質学的推定年代や同位体年代との矛盾を解明した.矛盾の原因は肥後変成岩と東清花商岩では同位体年代、氷上花商岩と京畿地塊では地質学的解釈、領家帯ミグマタイトと中国南東部花商岩ではCHIME年代にあった.