月球表面天然放射性元素Th的分布特征及月球化学的原始不均一性  

Natural radioactive thorium distribution at the lunar surface and it’s primary inhomogeneity of chemical composition

作　　者：李泳泉[1] 刘建忠[2] 欧阳自远[1] 郑永春[2] 李春来[2] 

机构地区：[1]中国科学院地球化学研究所 [2]中国科学院国家天文台,北京100012

出　　处：《地球化学》2006年第3期221-226,共6页Geochimica

基　　金：国家自然科学基金(40573047;40232026;40243019)

摘　　要：月球KREEP岩石形成于壳幔的分界层中,天然放射性元素Th是指示KREEP岩分布的主要元素之一。在月球正面,Th元素含量高的区域主要分布在西部的月海区,包括雨海和风暴洋及其附近地区,而在月球背面Th含量高的地区为雨海对峙区以及南极爱特肯地区。高地的Th含量相对较低。现代月球表面Th的分布特征与3.85Ga年前的雨海事件有重要的关系,且在月球正面还发现了椭圆形的高Th含量区域,是月球上特殊的地球化学省,与月球初期的化学成分分布的不均一性有关。KREEP rocks formed at the boundary of lunar crust and mantle, and natural radioactive thorium is one of the elements to demonstrate KRREP rocks distribution. On the nearside of Moon, high Th concentration areas mainly locate at the west part of mares, including Mare Imbrium and Oceanus Procellamm and nearby region. On the farside, high Th concentration areas locate at the antipode region of the Mare Imbrium and South Aitken. On the lunar highlands surface, Th concentration is relatively low. The thorium distribution at the lunar surface is significant related with Imbrium impact event occurred before 3.85 Ga. There exists high-Th oval region on the nearside, which is a special geochemical province in lunar surface, and it＇s related with the primary lunar crust inhomogeneity of chemical composition.

关 键 词：钍 KREEP岩 雨海事件 不均一性 月球 

分 类 号：P148[天文地球—天体物理] P184[天文地球—天文学]