The chemical and isotopic studies on the genethis and evolution of the lunar highland materials.

据推测，在月球表面有水存在的可能性。因此，我们从碱性元素和碱性土元素对硅酸盐物质溶解过程的影响角度出发，研究了水岩相互作用。结果表明，碱土阳离子，特别是Ca^<2+>和Sr^<2+>，促进了硅酸盐的溶解，并稳定了硅酸盐的溶解态。已知碱土元素在月球表面物质中富集，这一观测结果被认为对研究水与月球表面物质之间的相互作用是重要的。(2)月球陨石Asnka-881757是一种不同于阿波罗号样品的新型陨石。这颗陨石的辉长岩特征有38亿年的历史，被认为反映了古老的月球进化。稀土元素丰度表现为典型的“固体型”累积型。这表明月球辉长岩Asuka-881757代表了早期月球原始岩浆的堆积。(3) <-26>^Al或<41>^Ca等宇宙成因核素的定量分析，为开展行星表面物质历史的研究提供了可能。我们开发了一种新的电子循环分析系统。离子源和重离子直线加速器。利用该系统，我们成功地分析了几种样品中的多种微量元素，检测限在10^<-12>左右，无需任何样品制备。利用高达6 MeV/u的高能加速全绊行技术，实现了<26>^Al-<26>^Mg的分离，从而实现了对<26>^Al的高灵敏度检测。

(1) On the lunar surface, a possibility of the existence of water has been supposed. Therefore, we examined the water-rock interaction, based on the viewpoints of affection by alkaline and aikaline-earth elements on the dissolution process of silicate materials. We showed that the alkaline-earth cations, cspecially Ca^<2+> and Sr^<2+>, promoted the dissolution of silicate and stabilized the dissolved species of silicates. Alkaline-earth elements have been known to be enriched in the lunar surfacc materials and that observation is considered to be important to examine the interaction betwoen water and lunar surface materials.(2) A Iunar meteorite. Asnka-881757 is a new type of mcteorites distinct from Apollo samples. This meteorite gabbroic feature with the age of 3.8 billion years and has been coneidered to reflect old lunar evolution. Thc REE abundances shows a typical cumulate type, as it were "solid type", pattcrn. This implies that lunar gabbro, Asuka-881757, represents the carlier-stage cumulate for the primary lunar magma.(3) The quantitativo analyses of cosmogenic nuclides, such as <-26>^Al or <41>^Ca, make it possible to develop the studies on the history of surface planetary materials. We have developed the new analytical system which consists of ECR (electron cyc.lotron rosonance) ion source and heavy ion linear accelerator. Using this system, we succesefully analysed many trace elemente in several kinds of samples with the detoction limits around 10^<-12>without any sample preparations. Using the technique of full atripping by the high energy acceleration up to 6 MeV/u, <26>^Al-<26>^Mg separation has been achieved to detect <26>^Al with high sensitivity.