中文摘要：

徐家城遗址是甘肃省近年来发掘的一处旧石器时代晚期遗址，主要埋藏于陇西盆地水洛河二级阶地上覆的马兰黄土中，年代在距今约4．6～2-3万年间。本文使用原料最小单元分析这一目前国内尚未普及的方法对该遗址主文化层的石制品进行研究，涉及遗址形成过程、空间利用以及古人类的流动组织等方面。研究表明，古人类原地剥片行为是遗址主文化层石制品分布状态形成的主要原因，文化层交界位置所受扰动程度较大；石器工业面貌权宜性色彩较为浓厚，发掘区内并未呈现明显的功能分区，同一时期可能存在其他生活中心。本文对原料最小单元分析方法的适用性和潜力作了一定讨论。

英文摘要：

Refitting of chipped stone artifacts is an increasingly common research method in China. Grouping artifacts into raw material units is always the first step as the preparation for refitting. Refitting studies are very time consuming and sometimes only little is found to be fitted together. However, the units formed in the refitting process still yield useful information. We discuss minimum analytical nodules （MAN） and their analysis approach （MANA） as a means of further understanding site formation process, technological organization and mobility at the Xujiacheng site. The site buried in the Malan Loess overlying the second terrace of the Shuiluo River in Zhuanglang County, Gansu Province. Archaeological materials were mainly unearthedfrom the 4th and 5th layers. The assemblage used in this paper focuses on the 346 stone artifacts which were unearthed from the 4th layers. 11 different raw material nodules were identified including 124 stone artifacts. The minimum analytical nodules analysis shows that the distribution pattem of stone artifacts in the main archaeological layers were resulted from in situ stone flaking and retouch. The interruption is much stronger on the border between different layers. The stone artifacts have strong expedient characteristics. Basing on the limited area, it is difficult to separate different types of activity areas within the site. The MAN could not be refitted completely, suggesting some artifacts were moved in or removed from the site. The implications are that occupants of Xujiacheng primarily employed relatively short foraging trips around the local site, and there were likely several living centers coexisted in this area. MANA is applicable to assemblages that contain materials which are highly variable in color and texture. Limited by the lithic materials which were dominated by quartz and granite and small excavated area which is around 20m2, this research does not show all the potential of MANA. Future studies should combine all potentially useful methods togethe