Studies on the weathering and alteration of minerals by their fine texture analysis

通过精细结构分析研究矿物的风化和蚀变

• 批准号: 01540652
• 负责人: OZAWA Tohru
• 金额: $ 1.22万
• 依托单位: University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-01540652/
• 关键词: Brazil; Carbonatite; Weathering; Perovskite; Anatase; Magnetite; Alkaline rocks; Geikielite; ジャクピランジャイト; デュ-パル異常; 同位体測定; チタン鉄鉱; 微細組織; 鉱物風化; 鉱物の変質

In the Monbusho International Scientific Research Program since 1978 we sampled many rocks and minerals at various localities in the carbonatitealkaline complexes %, ; hich dot Brazilian shield. Main subjects of the present project are the surveys of weathering and alteration of the minerals with optical and electron microscopy, EPNIA and/or X-ray diffraction. The principal results are summarized as follows, in addition to the analysis of the general features of weathering and alteration.(1)Anatase crystals with a peculiar morphology have been mined together with phosphates for fertilizer in Tapira, Minas Gerais. The present studies on the fine texture and chemical composition of this anatase and perovskite obtained from the same mine, indicate that the anatase should be a weathering and alteration product of perovskite, and its peculiar morphology could be explained as a pseudomorph of perovskite.(2)The occurrence and exsolxition textxire of Ti-bearing magnetite collected in carbonati … More te-alkaline complexes have been investigated in order to help otir study on the origin of carbonatite. The present investigation has demonstrated that the magnetite often exsolves geikielite(MgTiO_3), irrespective of its age of intrusion or locality in Brazil.(3)On the investigation into a mica ivith unusual zoning, which obtained from carbonatites, we have reached the conclusion that it is closely related to the "alkaline metasomatism" caused by action of carbonate magma.(4)The occurrence of polymignyte, zirkelite and zirconolite in glimmerite, all of which belong to the Ca-Zr-Ti-O system, has been described.(5)Fine texture which arises from the contact metasomatism between jacupirangite and carbonate magma has been electronmicroscopically studied.(6)Lateritic weathering soils from carbonate rocks have been chemically investigated with radio activation analysis.(7)We report geochemical and isotopic data of carbonatite specimens from five Brazilian localities. These analyses indicate that carbonatite melts attribute their origin to asthenospheric mantle plume. Less

自1978年以来，在蒙布霍国际科学研究计划中，我们在不同地区的碳酸盐-碱性杂岩中采集了许多岩石和矿物。本项目的主要内容是利用光学和电子显微镜、电子探针和/或X射线衍射仪对矿物的风化和蚀变进行调查。主要研究结果如下：(1)在米纳斯吉拉斯塔皮拉与磷酸盐一起开采了具有特殊形貌的锐钛矿型晶体作为肥料。目前对同一矿样中的锐钛矿和钙钛矿的精细结构和化学成分的研究表明，该锐钛矿可能是钙钛矿的风化和蚀变产物，其独特的形貌可以解释为钙钛矿的假象。(2)碳酸盐…中含钛磁铁矿的赋存状态和析出文本为了更好地研究碳酸盐岩的成因，人们研究了更多的TE-碱性络合物。本文的研究表明，无论侵入年代或在巴西的位置，磁铁矿通常都会溶出硅钛矿(MgTiO_3)。(3)通过对一种来自碳酸岩的云母异常分带的研究，我们得出结论：它与碳酸盐岩浆作用引起的“碱性交代”密切相关。(4)闪锌矿中多沸石、锆石和锆石的产出，均属于Ca-Zr-Ti-O系。(5)用电子显微镜研究了珠光岩与碳酸盐岩浆接触交代产生的细微结构。(6)用放射性活化法研究了碳酸盐岩中的红壤风化土壤。(7)报道了巴西五个地区的碳酸盐岩样品的地球化学和同位素数据。这些分析表明，碳酸盐岩熔体的成因是软流圈地幔热柱。较少

项目成果

Tohru OZAWA, Hiroyuki HORIUCHI and Masayasu TOKONAMI: "Studies on the minerals in Alkalinecarbonatite complexes in Brazil." News of the Univ. Mus. Univ. Tokyo. No. 20. 1-3 (1990)

Tohru OZAWA、Hiroyuki HORIUCHI 和 Masayasu TOKONAMI：“巴西碱性碳酸岩复合体中矿物质的研究”。

床次 正安: "ブラジル産の希土類元素・放射性鉱物の放射化分析ーーーーカ-ボナタイトの希土類元素について" 立教大学原子炉利用共同研究成果報告書. 10-12 (1991)

Masayasu Tokotsugu：“来自巴西的稀土元素和放射性矿物的活化分析 - 关于碳酸岩中的稀土元素”立教大学核反应堆利用联合研究结果报告10-12（1991）。

豊田 和弘: "機器光量子放射化分析法による標準化石試料およびカ-ボナタイト風化土壤試料の分析" 東北大学原子核理学研究施設報告. 22. 117-122 (1989)

丰田一宏：“通过仪器光子活化分析对标准化石样品和碳酸岩风化土壤样品进行分析”东北大学核科学研究设施报告。22. 117-122 (1989)。

Masayasu TOKONAMI, Kazuhoro TOYODA, Hiroyuki HORIUCHI and Tohru OZAWA: "Radio activation analysis applied to minerals from Brazil containing rare-earth elements and radioactive elements --- On the rare-earth elements in carbonatite." Rep. Res. Center for

Masayasu TOKONAMI、Kazuhoro TOYODA、Hiroyuki HORIUCHI 和 Tohru OZAWA：“无线电活化分析应用于巴西含稀土元素和放射性元素的矿物——关于碳酸岩中的稀土元素。”

床次 正安: "ブラジル産の希土類元素・放射性鉱物の放射化分析・・・・カ-ボナタイトの希土類元素について" 立教大学原子炉利用共同研究成果報告書. 10-12 (1991)

Masayasu Tokotsugu：“来自巴西的稀土元素和放射性矿物的活化分析......关于碳酸岩中的稀土元素”立教大学核反应堆利用联合研究结果报告10-12（1991）。