塔里木盆地白垩纪宇宙尘的发现及其意义

The Discovery and Significance of the Cretuceous Cosmic Dust in Tarim Basin

塔里木盆地白垩纪灰褐色含油砂岩中发现的宇宙尘为硅质宇宙尘，该宇宙尘粘附于伊／蒙混层粘土矿物表面，近于理想球体，直径为６ｕｍ，具镶嵌结构。这一发现在我国白垩系尚属首次。在化学成份上该宇宙尘与已报导的宇宙尘相似，对已发现的宇宙尘氧化物成份的研究表明，地球物质中ＴｉＯ２／ＳｉＯ２，ＴｉＯ２／ＦｅＯ，ＦｅＯ／ＳｉＯ２分别为０．０１，０．１７，０．１。

The cosmic dust, which was found in the Cretaceous grey - brown oil - bearing sandstone occured in Tarim Basin, is siliceous cosmic dust. It was sticked on the surface of illite/smectite clay minerlas. Its shape appears to be the ideal sphere, the diameter of which is about 6um. And it has mosaic texture. It is the first time to find the cosmic dust in Cretaceous sedimentory rock in China.After comparing the chemical compositions of the comsic dust with those which were reported in literature. it is found they are very similar, and the Ti O2/SiO2, TiO2/FeO, and FeO/SiO2 ratio values are 0. 01, 0. 17 and 0. 1, respectively.