The geologic events causing oxygen isotopic alteration of sedimentary carbonate minerals in the rocks of the North and South Kitakami Belts.

导致南北北上带岩石中沉积碳酸盐矿物氧同位素变化的地质事件。

• 批准号: 16540415
• 负责人: MORIKIYO Toshiro
• 金额: $ 2.18万
• 依托单位: Department of Geology, Faculty of Science, Shinshu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16540415/
• 关键词: oxygen isotopes; sedimentary carbonate; Oshima orogeny; isotopic alteration; South Kitakami belt; 酸素同位体; 同位体再平衡; 炭酸塩

Carbon and oxygen isotope ratios were measured for calcite contained in non-metamorphosed calcareous clastic rocks from the North and South Kitakami Belts, northern Japan, ranging in age from late Permian to Cretaceous. The rocks studied include calcareous shales, calcareous sandstones, and diagenetic carbonate concretions. The calcite in the calcareous shales and sandstones has δ^<13>C values similar to that of marine limestones indicating its precipitation from seawater. On the other hand, δ^<18>O values of the calcite (+15.5‰ realative to SMOW, on an average) are lower than those of marine limestones by approximately 10‰, but remarkably uniform in spite of the diversity in its origin and in age. It is clear that calcite dose not retain its primary oxygen isotope ratios. The depletion in ^<18>O of the calcite is interpreted as being due to the result of isotope exchange with ^<18>O-poor aqueous fluids, which had infiltrated into the formations after the diagenesis.The carbonates contained in the strata deposited after the Oshima Orogeny do not show any sign of oxygen isotope alteration. Thus it is considered that the lowering in δ^<18>O in the carbonates is related to the hydrothermal activity during the Oshima orogeny.

测定了日本北部北上带南北两侧未变质的钙质碎屑岩中方解石的碳、氧同位素组成，年龄范围为晚二叠世至白垩纪。所研究的岩石包括钙质页岩、钙质砂岩和成岩碳酸盐结核。钙质页岩和砂岩中的方解石具有与海相石灰岩相似的δ^&lt；13&gt；C值，表明其来自海水。另一方面，方解石的δ^&lt；18&gt；O值(平均为+15.5SMOW值)比海相石灰岩低约10‰，但尽管其来源和年龄不同，‰^&lt；18&gt；O值却非常一致。很明显，方解石不能保持其主氧同位素比值。方解石方解石的亏损是与成岩后渗入地层的贫水流体进行同位素交换的结果。大岛造山世后沉积的地层中的碳酸盐没有表现出氧同位素变化的迹象。因此，认为碳酸盐岩中δ^&lt；18&gt；O的降低与大岛造山期的热液活动有关。

项目成果

The sources of phosphorus for the phosphatic rocks in the Toyoma Formation, northeastern Japan.

日本东北部丰山组磷岩的磷来源。

• 发表时间: 2004
• 期刊: Journal of Faculty of Science, Shinshu University 39
• 作者: T.Morikiyo;K.Matsunaga;K.Iwamasa;S.Kanisawa
• 通讯作者: S.Kanisawa

Geochemistry of carbon and oxygen isotopes in carbonatites of Siberia and Mongolia and some geodynamic consequences.

西伯利亚和蒙古碳酸岩中碳和氧同位素的地球化学以及一些地球动力学后果。

• 发表时间: 2004
• 期刊: Deep-seated magmatism, its sources and their relation to plume processes.
• 作者: N.Vladykin;T.Morikiyo;T.Miyazaki
• 通讯作者: T.Miyazaki

Finding dolomitic melnoite in the Laiwu-Zibo area, Shandong province, China.

在中国山东省莱芜-淄博地区发现白云质黑长石。

• 发表时间: 2004
• 期刊: Proceedings of Japan Academy Ser.B, 80
• 作者: A.Goto;H.Fujimaki;T.Morikiyo;T.Liu
• 通讯作者: T.Liu

Isotope-geochemical systematics of kimberlites and related rocks from Siberian platform.

西伯利亚地台金伯利岩及相关岩石的同位素地球化学系统学。

• 发表时间: 2006
• 期刊: Geology and Geophysics (In press)
• 作者: Kostrovitsky;S.I.;Morikiyo;T.;Serov;I.V.;Yakovlev;D.A.;Amirzhanov;A.A.
• 通讯作者: A.A.

About kimberlite origin (in Russian)

关于金伯利岩的起源（俄语）

• 发表时间: 2004
• 期刊: Doklady of Academy of Science, Russia 399
• 作者: S.Kostrovitsky;T.Morikiyo;I.Serov;A.Rotman
• 通讯作者: A.Rotman