High-precision dating of significant geologic phenomena in Post-Glacial age

后冰河时代重要地质现象的高精度测年

• 批准号: 09680177
• 负责人: OKUMURA Koji
• 金额: $ 2.3万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09680177/
• 关键词: Post-Glacial Age; Radiocarbon dating; Dendrochronology; Tephra; Mass movement; Paleoseismology; Tree-ring; Quaternary; 補正時代

In order to develop and popularize high-precision dating of significant geologic phenomena of the Post-Glacial age, we introduced a composite techniques of high-precision radiocarbon dating and relative dendrochronology. The first successful dating by wiggle matching, which gives better constraints on probabilty distribution of dendrocorrected radiocarbon age, was carried out for samples related with large mass-movment events and volcanic eruptions. For example, the age of the Kawago-daira tephra formarly dated as 2800 to 3300 yearsBP was precisely determined as 3120 Cal. years BP with a huge trunk sample of over 400 rings, 5 high-precision conventional dating with definite intervals of 75 to 100 years, and wiggle matching. For the relative dendrochronological analyses, we introduced very high resolution imaging of polished tree rings with 10000 dpi flatbed scanner. Scanned tree ring images are retouched and enlarged to make recognition and counting of the rings. This method of electronic tree ring analysis will improve the representability of tree-ring studies. On the other hand, recognition and dating techniques for paleo-earthquakes are refined through detailed analyses of lake deposits for chemical and physical signatures of faulting events that affected the lake environment. Once the horizon of disturbance is recognized, usual procedures for high-precision dating were., successfully applied. The investigators are propagating to the Japanese geologist the idea of high-precision dating and refinment of the dates for the advancement of precise chronology for all related sciences.

为了发展和推广后冰期重要地质现象的高精度定年技术，我们引进了高精度放射性碳定年技术和相应的树木年代学相结合的方法。首次成功地对与大质量运动事件和火山喷发有关的样品进行了摆动匹配测年，较好地限制了树木校正放射性碳年龄的概率分布。例如，川乡平火山碎屑岩的年龄被确定为2800年至3300年BP，通过400多个年轮的巨大树干样本，5个高精度的75年至100年的确定间隔的常规测年，以及摆动匹配，精确地确定为3120 Cal.年BP。对于相关的树木年代学分析，我们介绍了非常高的分辨率成像的抛光树轮与10000 dpi的平板扫描仪。对扫描的树木年轮图像进行了修图和放大处理，实现了年轮的识别和计数。这种电子树轮分析方法将提高树轮研究的代表性。另一方面，通过对湖泊沉积物进行详细分析，以获得影响湖泊环境的断层事件的化学和物理特征，从而改进了古地震的识别和定年技术。一旦确定了扰动层位，通常的高精度测年程序是：成功应用。调查人员正在向日本地质学家宣传高精度测年和改进日期的想法，以促进所有相关科学的精确年代学。

项目成果

Okuno M., Moriya I., Tanaka K.and Nakamura, T.: "6500 cal yr BP Eruption of Takahara Volcano, North Kanto, Central Japan." Kazan, Bull.Volcano.Soc.Japan.42. 393-402 (1997)

Okuno M.、Moriya I.、Tanaka K. 和 Nakamura, T.：“距今 6500 年，日本中部北关东高原火山喷发。”

Okuno, M., Nakamura, T., Moriwaki, H.and Kobayashi, T.: "AMS radiocarbon dating of the Sakurajima tephra group, southern Kyushu, Japan." Nuclear Instruments and Methods in Physics Research. B123. 470-474 (1997)

Okuno, M.、Nakamura, T.、Moriwaki, H. 和 Kobayashi, T.：“日本九州南部樱岛火山灰群的 AMS 放射性碳测年”。

D.P.Schwartz, D.Pantosti, K.Okumura, T.J.Powers, and J.C.Hamilton: "Paleoseismic investigations in the Santa Cruz mountains, California : Implications for recurrence of large-magnitude earthquakes on the San Andreas fault." Jour.Geophys.Res.103. 17985-180

D.P.Schwartz、D.Pantosti、K.Okumura、T.J.Powers 和 J.C.Hamilton：“加利福尼亚州圣克鲁斯山脉的古地震调查：对圣安德烈亚斯断层再次发生大规模地震的影响。”

鈴木毅彦・藤原 治・檀原 徹: "関東北部から東北南部に分布する第四紀テフラのフィッション・トラック年代" 第四紀研究. 37印刷中. (1998)

Takehiko Suzuki、Osamu Fujiwara 和 Toru Danhara：“从关东北部到东北南部分布的第四纪火山灰的裂变径迹年龄”，第四纪研究，37 版（1998 年）。

Okumura K., Koaze T., Ishii M., Matsumura N and Teraoka Y: "Radiocarbon dating of medieval trunks in central Japan-high precision age determination using wiggle matching-." Summaries of Researches Using AMS at Nagoya University. (IX). 64-75 (1998)

Okumura K.、Koaze T.、Ishii M.、Matsumura N 和 Teraoka Y：“日本中部中世纪树干的放射性碳测年 - 使用摆动匹配进行高精度年龄测定 -”。