著者

北川 浩之 Kitagawa Hiroyuki

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.24, pp.56-61, 2013-03

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Radiocarbon (14C) provides a way to date material that contains carbon with an age up to 50,000 years and is also an important tracer of the global carbon cycle. To obtain the calendar year, radiocarbon age is calibrated using radiocarbon calibration dataset such as IntCal09. However there is still uncertainty in the available radiocarbon calibration dataset prior to 12.5 thousand years before the present. Recently,the radiocarbon calibration dataset from the annual laminated (varve) sediments of Lake Suigetsu, Japan (35°35'N, 135°53'E), have been updated by more than 800 14C analyses of terrestrial materials which provide a comprehensive record of atmospheric (or terrestrial) radiocarbon to the present limit of the 14C method (Bronk Ramsey et al., 2013).炭素14年代測定法は、過去5万年間の年代決l定には無くてはならない年代測定法である。しかし、炭素14年代は暦年代とは一致しなく、炭素14年代から暦年代を推定するには炭素14年代キャリブレーションデータセットを用いた較正が必要である。過去12500年間の炭素14年代キャリブレーションセットは、年輪年代学の手法で年代決定された木材の高精度炭素14年代測定によって求められている。それ以前は、海洋試料の高精度炭素14年代測定結果に海洋のリザーバ効果の補正が行われデータから推定され、不確かさが残されていた。水月湖年縞堆積物の研究で、海洋のリザーバ効果の補正が必要がなくなり、考古学試料などの陸域試料に適用できる炭素14年代キャリブレーションデータセットが、炭素14年代測定法が適用できる全期間について求められた。

著者

椋本 ひかり 南 雅代 中村 俊夫 Mukumoto Hikari Minami Masayo Nakamura Toshio

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

no.26, pp.96-101, 2015-03

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Bone collagen, the organic fraction of the bone, is commonly used on 14C dating of bone, while it can not be used for cremated bone because of no remain of collagen. Meanwhile, recent studies have presented that carbonate hydroxyapatite (CHa), the inorganic fraction of the bone, can be used for 14C dating of cremated bone, though the CHa is easily contaminated by exogenous carbon and should be purified by chemical treatment. The purpose of this study is to test the reliability of 14C dating of CHa by using a cremated bone of known-age in Japan. The samples used were the cremated bone, which is considered to be remains of Jokei, a Buddhist monk (AD 1155-1213). We examined whether chemical treatment of the cremated bone with 0.1 M acetic acid for a short time of 1 hour is adequate for removal of secondary carbonate to obtain innate CHa for accurate 14C dating. The CHa in six fragments of the cremated bone showed 14C dates between 1155-1280 cal AD, which are similar with the supposed age. The result indicates the effectiveness of acetic acid treatment and the possibility of accurate 14C dating of CHa by the appropriate chemical treatment. 骨の14C年代測定には、有機成分であるコラーゲンを利用するのが一般的である。しかし、コラーゲンが損失しているため、14C年代測定が困難な骨試料も少なくない。そのような骨試料、特に火葬骨に対して、近年、無機成分の炭酸ヒドロキシアパタイト(CHa)を用いた14C年代測定が試みられている。そこで、本研究では、年代既知の火葬骨に対して、実際に、CHaを用いて信頼性のある14C年代測定が可能かどうかの検証を行った。また、二次的な炭酸塩による汚染を除去するための低濃度短時間の酢酸処理の有効性についても評価を行った。用いた火葬骨試料は、奈良県三郷町の持聖院に所蔵されていた蔵骨器内の骨片である。この人骨は、平安時代末から鎌倉時代にかけて活躍した僧・貞慶(AD1155-1213)の遺骨であるとされている。年代測定の結果、本研究で使用した火葬骨6点から得られた14C年代は1155-1280cal ADという、貞慶の没年と2σの誤差範囲で一致する結果となった。一方、酢酸処理により発生したC02は現代に近い年代を示したことから、本研究で使用した火葬骨は、2次的な炭酸塩等の外来炭素の汚染があったものの、酢酸処理によって効果的に除去された結果、CHaの信頼性のある14C年代測定が可能であったことがわかった。また、真空下における、0.1Mの酢酸による1時間程度の酸処理の有効性も明らかになった。今後、より年代の古い試料や保存状態の異なる試料についても検討を行っていく予定である。名古屋大学年代測定総合研究センターシンポジウム報告

著者

渡邊 隆広 WATANABE Takahiro 奈良岡 浩 NARAOKA Hiroshi 西村 弥亜 NISHIMURA Mitsugu 中村 俊夫 NAKAMURA Toshio 仙田 量子 SENDA Ryoko 河合 崇欣 KAWAI Takayoshi

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.15, pp.199-205, 2004-03 (Released:2010-06-03)

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タンデトロン加速器質量分析計業績報告 Summaries of Researches Using AMS 2003 (平成15)年度

著者

植村 恒仁 Uemura Tsunehito 宮原 ひろ子 Miyahara Hiroko 村木 綏 Muraki Yasushi 増田 公明 Masuda Kimiaki

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.13, pp.110-117, 2002-03

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It is known that the periods when solar activity was extremely weak (so-called grand minima) existed several times in the last 1000 years. It is reported by Kocharov et al. that the solar activity periodicity during the Maunder minimum was not the 11 year variation but the 22 year variation. What does the cycle of 22 years mean? Does the periodicity of 22 years exist also in the minima other than the Maunder minimum? We have investigated the solar activity of the Sporer minimum, which preceded the Maunder minimum, in order to understand the periodicity of solar activity during the minima. Both the liquid scintillation method and the accelerator mass spectrometry method (AMS method) were used for measuring the ^<14>C concentration in annual tree rings.

著者

宇田津 徹朗 Udatsu Tetsuro

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.24, pp.113-122, 2013-03

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In order to study about the formation and development of the rice paddy cultivation technology in East Asia, it is important to arrange correctly the result (data) taken in various fields, such as agriculture, botany, and archaeology, in the time and space. This report is discussing rice paddy cultivation of East Asia, introducing the result of the field survey in China or Japan. And, I also introduce about a part of result of the study (Study on age determination by carbon in plant opal collected from ancient agricultural field) which we are tackling now.

著者

中村 俊夫 宇田津 徹朗 田崎 博之 外山 秀一 杉山 真二 松田 隆二 Nakamura Toshio Udatsu Tetsuro Tazaki Hiroyuki Toyama Shuichi Sugiyama Shinji Matsuda Ryuji

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.24, pp.123-132, 2013-03

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To measure 14C age directly on plant opal itself with accelerator mass spectrometry (AMS), we have extracted carbon contained in plant-opal samples separated from modern lining plants as well as ancient soil deposits at archeological sites, in particular, rice field remains. Carbon dioxide was separated and collected from plant-opal samples by using a radio-frequency furnace (HF-1O, Leco Corporation) which is used successfully to extract carbon in the metal iron. Carbon content of plant opal is not clearly known, and yields of CO2 from p1ant-opal samples were very low (<0.1%) in our experiment Nagoya University AMS 14C dating laboratory. We have conducted CO2 extraction for 15 samples, and we can get enough CO2 from only three samples to perform 14C dating even with AMS. The obtained 14C ages were a few thousand years older than expectations on the basis of archeological aspects. Even more, plant-opal samples extracted from modern living plants showed 14C ages as old as 3-6 ka BP. This implies that carbon in plant opal is not derived from carbon incorporated into the plants by photosynthesis. More studies are required to apply routinely 14C dating of plant-opal material.

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

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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

宮原 ひろ子 Miyahara Hiroko 毛受 弘彰 Menjo Hiroaki 桑名 宏輔 Kuwana Kousuke 増田 公明 Masuda Kimiaki 村木 綏 Muraki Yasushi 中村 俊夫 Nakamura Toshio

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.16, pp.57-64, 2005-03

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This paper presents the variation of solar activity during the Maunder Minimum (1645-1715 AD) deducted from radiocarbon content in tree-rings. Radiocarbon is produced by the galactic cosmic rays, which are modulated by the solar wind and the interplanetary magnetic field in the heliosphere. The production rate of radiocarbon, therefore, reflects the state of solar magnetic activity. Most distinct index of solar magnetic activity it the group sunspot number. The variations of sunspot number have shown clear cyclicity since the 18^<th> century with average length being about eleven years. The sunspots, however, have once almost disappeared during the period of 1645-1715 AD due to extraordinary weakening of solar activity. This period has been called as the Maunder Minimum. There is no remarkable cyclicity in the sunspot variations. We, therefore, investigated the cyclicity of radiocarbon content in tree rings from the Maunder Minimum in order to clarify the characteristics of solar activity during this period. We compared two radiocarbon records obtained newly by our group and by Stuiver et al. The results of frequency analyses have shown that solar magnetic reversals had maintained through the Maunder Minimum and that the length of the "eleven-year" cycle was stretched to 13-15 years.

著者

中村 俊夫 太田 友子 山田 哲也 Nakamura Toshio Ohta Tomoko Yamada Tetsuya

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.26, pp.150-155, 2015-03

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It is well known that ages of ancient iron artifacts can be measured by using carbon contained in the iron artifacts. As a simple method of carbon extraction from iron artifacts, a normal quartz tube is used for metal iron combustion at the temperature of 1000℃ for about 15 hrs. We tested the quartz tube method of metal iron combustion successfully for metal iron in fine fragment forms and reported the results previously. In Japan, iron rust samples are commonly excavated from archeological sites of the Kofun period and after. We have tested to collect carbon from iron rust samples successfully by the quartz tube method of iron-rust combustion at 850℃ for 3 hr. We have experienced that quartz tubes were broken twice during combustion: at 900℃ for 8 hr and at 850℃ for 3 hr. 14C age, 524±25 BP, was obtained for an iron rust sample from a ruin of Fe manufacturing site worked at 1850s in Saga city, Saga Prefecture, Japan. The 14C age was too old compared with the estimated age of the site. 14C ages were also obtained for three rusty nail samples as 2949 -3244 BP. The results suggested a possibility of modern carbon contamination in considerable amount during rust process of metal iron that was produced by using coal as a heating fuel as well as material to reduce iron oxide ore.名古屋大学年代測定総合研究センターシンポジウム報告

著者

冨田 純治 鈴木 和博 Tomita Jun-ji Suzuki Kazuhiro

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.25, pp.212-228, 2014-03

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名古屋大学年代測定総合研究センターシンポジウム報告

著者

中川原 育子 谷口 陽子 佐藤 一郎 中村 俊夫 NAKAGAWARA Ikuko TANIGUCHI Yoko SATO Ichiro NAKAMURA Toshio

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.23, pp.127-137, 2012-03 (Released:2013-06-06)

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The Kizil Grottoes, the largest Buddhist monastery complex in the Xinjian region of China, is decorated with wall paintings - the chronological dates of which are still under debate. This study aims to give some clarification regarding the chronological dates using AMS-14C dating of chaff tempers taken from the earthen renders of the wall paintings. l4C studies previously carried out by Chinese and German researchers had resulted in divergent dates often extending back hundreds of years earlier than hypothesized within the chronology of art history, which has created confusion. Six samples from six wall painting fragments (Caves 8 [III8425], 38 [III8700], 171 [III8793, III8891], 207[III9148b(d)], and 224[III8865(a)]) held in collections at the Museum für Asiatische Kunst in Berlin were taken and analysed with 14C-AMS at the Center of Chronological Research at Nagoya University in Japan. As reference, nine dating results analysed between 1995 and 1998 at Nagoya University were also shown in the list. Dates were obtained for only three out of the six samples: cal AD 128-216 [Cave 8], cal AD 255-306 and cal AD 312-34 [Cave 171], and 90-70 cal BC [Cave 224]; most of these extended back earlier than reference 14C data from the Chinese and German studies and far earlier than dates suggested by the timeline of art history. Even the Chinese and German reference dates derived in the past from 14C analysis often show varied dates occurring earlier than those represented in art history. This may indicate that old chaff was used in renders for the Kizil wall paintings probably as a form of re-use of old mud bricks, or that the chronology of art history must be drastically reconsidered, both of which would require further AMS-14C dating studies with careful and comprehensive sampling from well-documented contexts.

著者

植村 恒仁 Uemura Tsunehito 宮原 ひろ子 Miyahara Hiroko 村木 綏 Muraki Yasushi 増田 公明 Masuda Kimiaki

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.13, pp.110-117, 2002-03 (Released:2010-06-01)

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It is known that the periods when solar activity was extremely weak (so-called grand minima) existed several times in the last 1000 years. It is reported by Kocharov et al. that the solar activity periodicity during the Maunder minimum was not the 11 year variation but the 22 year variation. What does the cycle of 22 years mean? Does the periodicity of 22 years exist also in the minima other than the Maunder minimum? We have investigated the solar activity of the Sporer minimum, which preceded the Maunder minimum, in order to understand the periodicity of solar activity during the minima. Both the liquid scintillation method and the accelerator mass spectrometry method (AMS method) were used for measuring the ^<14>C concentration in annual tree rings.

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

永治 健太朗 増田 公明 Nakamura Toshio 三宅 芙沙 村木 綏 中村 俊夫 Miyake Fusa Nagaya Kentaro Masuda Kimiaki Muraki Yasushi

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.23, pp.63-68, 2012-03

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名古屋大学年代測定総合研究センターシンポジウム報告

著者

桧垣 大助 上田 豊 梅村 順 伏見 硯二

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

no.16, pp.144-147, 2005-03

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タンデトロン加速器質量分析計業績報告 Summaries of Researches Using AMS 2004 (平成16)年度