月球陨石NWA16470与NWA16471的类型划分和成对性分析

打开文本图片集

Abstract： Lunar meteorites serve as superior carriers for lunar research compared to returned samples. In this study， we investigate the petrography and mineralogy of two newly discovered lunar meteorites，NWA l6470 and NWA 16471.The results show that NWA 16470 and NWA 16471 are anorthositic gabbro lunar polymict breccia meteorites. The lithic clastsconsist largelyof anorthosite，gabbro，and troctolite.The mineral detrital is mainly composedof plagioclase，pyroxene，and olivine.Trace phases include ilmenite，troilite，chromite，and Fe and Ni metals.The mineral chemistry of the two meteorites is as folows： the composition of plagioclase is homogeneous （NWA 16470： An96.0～97.2Ab2.5～3.9 ， NWA 16471： An94.0-97.3Ab2.7～5.7） ; the pyroxene is mainly augite， pigeonite， and hypersthene （NWA 16470： Fs23.9～35.3Wo4.0～28.2En44.3～71.2. ，NWA 16471： Fs12.0-37.8Wo4.0-41.1En43.2-73.2） ； and the olivine has a wide range of components （NWA 16470： Fo54.5～80.2 ，NWA 16471： Fo52.5～74.3） .The characteristics of trace elements are consistent withotherreported lunar meteorites.Additionally，both meteoritesshowanenrichmentoflightrareearthelements and a positive anomaly inEu，with SEu values ranging from 2.1 to16.9.Our analysis is basedon the rock texture， mineral composition， detrital composition， whole rock composition，and trace element relationships （Sm-Sc and Eu/Sm-Sc of these meteorites，including acomparison with lunar meteorites previouslystudied.Itisconcludedthat themajorityof the components of NWA 16470 and NWA 16471 are from the lunar highlands， with a smallportion of lunar mare. Although NWA 16470 and NWA l6471 have the same discovery time， place and appearance， they have certain diferences in terms of mineral and chemical composition，implying they cannot be identified as a meteorite pair.

Key words： lunar meteorites；lunar breccia； petromineralogy； paired meteorites

月球陨石作为月球物质的重要来源，为研究月球表面组成和演化提供了关键线索（欧阳自远，2005;Korotev，2005）。（剩余16768字）