中文摘要：

新疆罗布泊以东65 km处的三峰山区域发现了陨石（Tuya 002～007）散落区,呈3 km×11 km的椭圆状.散落区内收集到130余块普通球粒陨石,总重超过160 kg,最大的陨石重30 kg,最小的陨石重约15 g.散落区为一南东-北西向分布且陨石样品逐渐增大的椭圆形区域,这意味着陨石从南东向以较低的角度进入地球大气层.除Tuya002（760 g）外,散落区内的陨石可能来自同一次陨石雨,陨石类型为L5,冲击程度为S2,风化程度为W3.Tuya 003的宇宙射线暴露年龄为45.6±4.4 Ma,因此三峰山陨石雨的流星体可能形成于约40 Ma时普通球粒陨石L群母体的破裂事件中.Tuya 002具有和其他三峰山陨石显著不同的外表特征,表面熔壳全部脱落,球粒清晰可见,为L4型普通球粒陨石,样品中有大量的硫酸钙.其宇宙射线暴露年龄为17.0±4.1 Ma,也证明了其不是三峰山陨石雨的产物.三峰山区域陨石的研究表明三峰山区域不是陨石富集区,而是L5普通球粒陨石散落区.因此,需要对其他一些区域的陨石样品进行矿物岩石学、风化特征、宇宙射线暴露年龄和居地年龄的研究,从而确定出新疆及其周边沙漠区域的陨石富集区.

英文摘要：

The meteorites are the most important extraterrestrial samples for understanding the formation and the evolution history of the solar system, although ～382 kg lunar samples and ～1500 asteroid mineral grains have been returned by human space exploration activities. The Northwest region of China, especially the Xinjiang, has a vast area of sandy deserts and Gobi Deserts. The lower annual rainfall and the dry climate of this region provide a good condition for meteorite preservation. In recent years, the number of recovered meteorites from the Gobi Deserts in Xinjiang increased significantly. The Sanfengshan area, located about 65 km east of Lop Nor, is one of the research regions. We first collected three ordinary chondrites in Sanfengshan area on October 9, 2013. Then, we carried out 11 meteorite search campaigns in this area. More than 130 meteorite fragments with a total mass over 160 kg have been recovered. The map of all collected Sanfengshan meteorites depicts a clearly 3 km×11 km elliptic strewn field. The sizes are sorted in the SE-NW-oriented ellipsoid of the strewn field, therefore indicating that the meteor entered the atmosphere from SE at a low angle relative to the ground. In this study, six meteorites（Tuya 002–007） from the Sanfengshan field have been measured using a Scios-FIB field emission scanning electron microscope（SEM）, a JXA 8230 electron microprobe analysis（EMA）, and a self-made noble gas mass spectrometer. Among all of the collected meteorites, Tuya 002 is the only one unusual sample, which doesn＇t show any fusion crust on its surface. We inferred that Tuya 002 is not paired with the other collected meteorites. The well-defined chondrule boundaries and heavy weathering grade, i.e. W3（the occurrence of large amounts of calcium sulfate in Tuya 002 indicates that it suffered a heavy terrestrial weathering） also support the conclusion that Tuya 002 is obviously different from the other meteorites collected in the Sanfengshan area. In addition to Tuya 002, all the meteor