MICROPROBE ANALYSES OF REE AND HALOGENS IN ACCESSORY MINERALS,ESPECIALLY FOR APATITE

微探针分析副矿物中的稀土元素和卤素，特别是磷灰石

• 批准号: 03640669
• 负责人: YAMAGUCHI Yoshiaki
• 金额: $ 1.28万
• 依托单位: FACULTY OF SCIENCE,SHINSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 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/grant/KAKENHI-PROJECT-03640669/
• 关键词: REE; Halogene; Microprobe analysis; Accessory minerals; Apatite; 石基ガラス; ハロゲンおよびS; 脱ガス; 溶岩ド-ム; 火砕硫; 石英安山岩; 雲仙岳

The halogene and rare-earth elements in accessory apatite,allanite and zircon from some dome dacites and granite have been investigated using the electron microprobe. For these purpose,the system and the method by use of a JXA-50A microanalyzer were improved in performing microprobe analysis at low concentrations of minor element,such as,fluorine,chlorine,strontium,yttrium, REE,zirconium,hafnium and thorium. Methods of spot analysis were applied for analysis of very fine apatite microlite in groundmass of dacitic volcanic rocks and for that of zoned allanite and zircon crystal in some granitic rocks.Pulse height analyzer were put to practical use for improvement in peak/backbround intensity ratio. The ZAF correction methods were deveroped for calculation using intensity data of characteristic X-ray at different accelerating voltages. Intensity data of major elements were obtained under a operating condition of 2x10^<-8>A specimen current at 15 kV accelerating voltage. Analyses of fluorine,chlorine and the other minor elements were made under 8x10^<-8>-1.5x10^<-7>A at 20-25 kV accelerating voltages. The detection limits thus achieved were as follows; F 200 ppm,Cl 40 ppm,Y 210 ppm,La 100 ppm,Ce 100 ppm,Nd 230 ppm,Er 120 ppm,Yb 120 ppm,Th 200 ppm.Resultant analyses of apatite microlite in groundmass of the dome dacites indicate that halogene contents of apatite were useful indicator of degassing of magma. In granitic rocks high concentrations of REE in these accessory minerals indicate that they contain the greater proportion of whole-rock REE. Allanite dominantly plays important role in fractionation of light REE in evolution of felsic magma.

用电子探针研究了部分圆顶英安岩和花岗岩中伴生磷灰石、allanite和锆石中的卤素和稀土元素。为此，对该系统进行了改进，并利用JXA-50A微量分析仪对低浓度微量元素（如氟、氯、锶、钇、稀土、锆、铪和钍）进行了微探针分析。应用斑点分析方法对英安质火山岩地块中极细磷灰石微岩和部分花岗质岩石中分带的allanite和锆石晶体进行了分析。为了提高峰值/背景强度比，将脉冲高度分析仪投入实际应用。利用不同加速电压下的特征x射线强度数据，建立了ZAF校正方法。在15 kV加速电压下，试样电流为2 × 10^<-8> a的工作条件下，获得了主要元素的强度数据。在20- 25kv加速电压下，在8x10^<-8>-1.5x10^<-7>A下对氟、氯和其他微量元素进行了分析。由此达到的检出限如下：F 200ppm,Cl 40ppm,Y 210ppm,La 100ppm,Ce 100ppm,Nd 230ppm,Er 120ppm, yb120ppm,Th 200ppm。对穹状英安岩基底中磷灰石微岩的综合分析表明，磷灰石卤素含量是岩浆脱气的有用指示物。在花岗质岩石中，这些副矿物中稀土元素含量高，表明它们占全岩稀土元素的比例较大。在长英质岩浆演化过程中，Allanite在轻REE分馏中起主导作用。

项目成果

Kuroda,Y.,Yamada,T.,Yamaguchi,Y.,Matsuo,S.,Kanisawa,S.,Maruyama,T.and Morikiyo,T.: "Correlation of granitie rocks in the Baltic shield and Japanese island arc (IGCP‐315)" Japan contribution to the IGCP 1992. 73-76 (1992)

Kuroda, Y.、Yamada, T.、Yamaguchi, Y.、Matsuo, S.、Kanisawa, S.、Maruyama, T. 和 Morikiyo, T.：“波罗的海地盾和日本岛弧中花岗岩岩石的相关性（IGCP） ‐315)" 日本对 IGCP 1992 的贡献。73-76 (1992)

Kuroda,Y.,Yamada,T.,Yamaguchi,Y.,Matsuo,S.,Kanisawa,S.,Maruyama,T. and Morikiyo,T.: "Correlation of granitic rocks in the Baltic shield and Japanese island arc(IGCP-315)" Japan contribution to the IGCP 1992. 73-76 (1992)

黑田Y.、山田T.、山口Y.、松尾S.、鹿泽S.、丸山T.

Kuroda,Y.,Yamada,T.,Yamaguchi,Y.,Matsuo,S.,Kanisawa,S.,Maruyama,T.and Morikiyo,T: "Correlation of granitic rocks in the Baltic shield and Japanese Island arc (IGCP-315)" Japan contribution to the IGCP. 1992. 73-76 (1992)

Kuroda，Y.，Yamada，T.，Yamaguchi，Y.，Matsuo，S.，Kanisawa，S.，Maruyama，T. 和 Morikiyo，T：“波罗的海地盾和日本岛弧中花岗岩的相关性（IGCP-

山口 佳昭,日下部 実,河野 美香,三宅 康幸: "雲仙火山1991ド-ム溶岩の石基ガラスおよび石基含水鉱物のCl,F,S含有量" 地球惑星科学関連学会1992年合同大会 1992年4月7日ー10日. (1992)

Yoshiaki Yamaguchi、Minoru Kusakabe、Mika Kono、Yasuyuki Miyake：“1991 年云仙火山圆顶熔岩的岩石基玻璃和岩石基水合矿物的 Cl、F 和 S 含量” 1992 年地球与行星科学协会联合会议 1992 年4 (1992)