Structure and isotopic composition of carbonate rocks.

碳酸盐岩的结构和同位素组成。

• 批准号: 03453054
• 负责人: MATSUMOTO Ryo
• 金额: $ 3.2万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03453054/
• 关键词: carbonate rocks; isotopic composition; cathodoluminescence; sea-level change; calcite cement; strontium; カソ-ドルミネッセンス

1. Recognition of types of carbonate cement by means of CL-image method: Non-luminescent rim-cement of marine origin and dull to bright luminescent, sparry, drusy cement of freshwater origin have been recognized in such limest ones as; Silurian limestones of Gotland, Jurassic limestones of Nepal-Himalaya and Soma-Fukushima, and Quaternary Ryukyu Limestone of Kikai Island. Roof-pendant type, vadose cements with characteristic zoned patterns have also been recognized for the Silurian Limestone of Gotland, suggesting that the cementation took place under the fluctuating conditions in terms of Eh and Mn concentration. Thus, CL-image method has been proved to be a powerful and useful technique for identification of various cement types. 2. Comparison between luminosity and carbonate chemistry: SEM-EDS analyses on selected samples have revealed that bright-luminescent carbonate contains more Mn than dull to non-luminescent carbonates. Mn-bearing carbonates are considered to have been formed in relatively reduced environments. This implies that bright-luminescent carbonates were formed under oxygen-deficient conditions. 3. Determination of oxygen, carbon, and strontium isotope compositions for micro-samples: Carbon isotopic signatures, mostly within *3 permil, suggest that major phase of carbonate cementation occurred near-surface environments which were open to sea-water and atmosphere. Supposing the near-surface diagenesis, the temperature of precipitaion and/or mixing ratio of sea- water and ground water are estimated from oxygen and strontium isotopic compositions. 4. Chemical and isotoipic analyses would provide critical data concerning diagenetic and sedimentary environments of carbonates only when the micro-textural analyses and the characterization of cement- types had been done. In this sense, CL-image tecnique is very important in carbonate sedimentology.

1.用CL-IMAGE方法识别碳酸盐胶结物的类型：在最灰岩中已识别出海相的无发光边缘胶结物和暗淡到明亮的发光、闪亮、干硬的淡水胶结物；哥特兰的志留系石灰岩、尼泊尔-喜马拉雅和索马-福岛的侏罗纪石灰岩，以及基开岛的第四纪琉球石灰岩。戈特兰志留系灰岩中还发现了顶垂型包气胶结物，具有明显的分带特征，表明胶结作用是在Eh、Mn含量波动的条件下进行的。因此，化学发光成像法已被证明是一种强有力的水泥类型识别技术。2.光度与碳酸盐化学的比较：对所选样品的扫描电子显微镜-能谱分析表明，发光碳酸盐中的锰含量高于无发光碳酸盐的含锰量。含锰碳酸盐被认为是在相对还原的环境中形成的。这意味着明亮发光碳酸盐是在缺氧条件下形成的。3.微量样品氧、碳、锶同位素组成的测定：碳同位素特征表明，碳酸盐胶结作用的主要相存在于开放于海水和大气的近地表环境中。假定为近地表成岩作用，根据氧、锶同位素组成估算了海、地下水的沉淀温度和/或混合比。4.只有在进行了胶结物类型的微观结构分析和表征之后，化学分析和等速分析才能提供有关碳酸盐成岩和沉积环境的关键数据。从这个意义上说，化学发光成像技术在碳酸盐沉积学中是非常重要的。

项目成果

松本 良: "ユロキウム「炭酸塩と地球環境」" 推積学研究会報. 37号. 101-103 (1992)

Ryo Matsumoto：“Yurokium 碳酸盐和全球环境”估计研究杂志第 37 期。101-103 (1992)。

OGIHARA,shigenori: "Non-marine phosphorite nodules from Kusu basin, Oita Prefecture." Mining Geology. 42. (1992)

OGIHARA,shigenori：“来自大分县玖珠盆地的非海相磷矿结核。”

荻原 成騎: "大分県玖珠盆地産出の非海成燐酸塩1ジュール" 資源地質(Mining Geology). 42. 249-257 (1992)

Seiki Ogihara：“大分县楠洲盆地的 1 焦耳非海相磷酸盐”《采矿地质学》42. 249-257 (1992)。

MATSUMOTO,ryo: "Burial diagenesis and paleoenvironments of Japan Sea read from carbonate nodules" Earth monthly. 6. 254-257 (1992)

松本亮：“从碳酸盐结核中解读日本海的埋藏成岩作用和古环境”地球月刊。

松本 良: "炭酸塩1ジュールから読む埋没続成史と日本海古環境" 月刊・地球. NO.6. 254-257 (1992)

Ryo Matsumoto：“从1焦耳碳酸盐看埋藏成岩历史和日本海古环境”，地球月刊第6期（1992年）。