Fundamental study on rhenium - osmium dating for mudstones

泥岩铼-锇定年基础研究

• 批准号: 13640460
• 负责人: TERAKADO Yasutaka
• 金额: $ 2.18万
• 依托单位: Kobe University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640460/
• 关键词: rhenium; osmium; dating; sedimentary rocks; レニウム・オスミウム法; 硫化鉱物; 質量分析; 微量元素

An early stage of the present project, developmental efforts for Re-Os analyses were made. The Re mass spectrometry was usually disturbed by filament blank, but finally successful measurements were attained. However, the contribution of filament Re is still large, and our efforts must be given to reduce such effect.The Re-Os dating method were applied to several kinds of samples such as Permian Akasaka limestones, late Jurassic mudstones from Tamba group, Miocene mudstones from Shimane Prefecture, present-day river and marine sediments. Those data indicate two important aspects: (1) Most of the limestones and mudstones undergone severe thermal event during diagenetic processes are not suitable for Re-Os dating. Re might tend to be mobilized during such processes. (2) However, relatively young mudstones, which did not undergo thermal damage, can yields reasonable age, and thus are suitable for Re-Os dating.Finally, although application of Re-Os method to sedimentary rocks might be restricted to relatively young rocks, this method must deserve attention for further geological investigations.

在本项目的早期阶段，进行了铼-锇分析的开发工作。铼质谱通常受到灯丝空白的干扰，但最终获得了成功的测量。对二叠纪赤坂灰岩、丹波群晚侏罗世泥岩、岛根县中新世泥岩、现代河流和海洋沉积物等样品进行了Re-Os定年。这些数据表明两个重要方面：（1）大多数灰岩和泥岩在成岩过程中经历了严重的热事件，不适合进行Re-Os定年。在这些过程中，再循环可能会被调动起来。(2)然而，相对年轻的泥岩，没有受到热损伤，可以得到合理的年龄，因此，Re-Os法的应用可能仅限于沉积岩相对年轻的岩石，但这种方法必须注意进一步的地质调查。

项目成果

M.Otsuka, Y.Terakado: "Rare earth element abundances in high phosphorus and low iron groundwaters from the Nishinomiya district, Japan"Geochemical Journal. 37・1. 1-19 (2003)

M. Otsuka，Y. Terakado：“日本西宫地区高磷和低铁地下水中的稀土元素丰度”地球化学杂志 37・1（2003 年）。

Taiga Nakajima, and Yasutaka Terakado: "Rare earth elements in stream waters from the Rokko granite area, Japan: effect of weathering degree of watershed rocks"Geochemical Journal. Vol. 37. (2003)

Taiga Nakajima 和 Yasutaka Terakado：“日本六甲花岗岩地区溪水中的稀土元素：分水岭岩石风化程度的影响”地球化学杂志。

T.Nakajima, Y.Terakado: "Rare earth elements in stream waters from the Rokko granite area, Japan : effect of weathering degree of watershed rocks"Geochemical Journal. 37・2. 181-198 (2003)

T. Nakajima，Y. Terakado：“日本六甲花岗岩地区溪水中的稀土元素：分水岭岩石风化程度的影响”地球化学杂志 37・2（2003）。

Y.Terakado: "Re-Os dating of the Kuroko ore deposits from the Hokuroku district, Akita Prefecture, Northeast Japan"J.Geological Soc.Japan. 107・5. 354-357 (2001)

Y. Terakado：“日本东北部秋田县黑子矿床的 Re-Os 定年”J.Geological Soc.Japan 107・5（2001）。