Abstract: With the continuous discoveries since 1995, Luonan Basin in central China have become one of the most important area having its high density of Paleolithic sites with the surprising quantity of stone artifacts. Up to date, more than 300 Paleolithic sites was identified, from which over 150,000 stone artifacts were recovered from either surface collection or excavation. During 2010-2013, to coordinate with the highway construction projects in Shaanxi province, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP, CAS), Shaanxi Provincial Institute of Archaeology, Nanjing University and Museum of Luonan County conducted a field survey/excavation on the second terrace of the South Luohe River in the Luonan Basin. Numerous Paleolithic open-air site were identified which including Yeyuan loci. The site fall into an area of 34°04′23.4″N, 110°05′54.9″E, with an altitude at 1016.4m above sea level. This paper will focus on the 617 artifacts which collected at about 3,000 square meters of the Yeyuan loci. The stone assemblage is consist of cores (n=202, 32.74%), flakes (n=210, 34.04%), chunks (n=103, 16.69%), chips (n=14, 2.27%) and various retouched tools (n=88, 14.26%) such as choppers (n=11), picks (n=6), hand-axes (n=5), knife (n=1), cleavers (n=3), scrappers (n=59), points (n=2), and burin (n=1). The analytic resultsuggests that the stone artifacts from Yeyuan site were made of local raw materials which come from the cobbles/pebbles of the South Luohe River which are mainly quartzite (58.68%) and quartz (32.41%), although greywacke and fine sandstone are also occasionally used. Most stone artifacts are small (<50mm) and medium (50~100mm) in size, but finely retouched tools such as hand-axes, cleavers and knife are large in size. The principal flake knapping method is direct hammer percussion, along with bipolar method and anvil-chipping method. Cores analysis show a rather high utilization rate and no classic Levallois cores and Levallois flakes were identified. The tools are mainly bifacially retouched flake tools, cores, pebbles and chunks are also occasionally used as blanks. Most tools are medium (50~100mm) or large (>100mm) in size, and the Acheulian-type large cutting tools (LCTs) such as hand-axes, picks, cleavers and knife are finely retouched. Base on a series of chronological data and stratigraphic analysis, we put forward the age of the stone artifacts which collected on the second terrace is late middle Pleistocene to late Pleistocene, and the Acheulian-type large cutting tools (LCTs) such as hand-axes, picks and cleavers in the Luonan Basin should be considered rather important for the discussion of LCTs variation between the West and the East sides of the Movius Line. Based on the previous research, we consider that the Acheulian-type LCTs in the Luonan Basin, Danjiang River valley and the sites in east Qinling Mountains are resemble to Acheulian ones in the west of the Movius Line. This suggest that Luonan LCTs may came from the same technological tradition, which indicated the intermittent dispersals of populations manufacturing Acheulian bifacial tools.

Key words: Luonan Basin; Yeyuan open-air site; Paleolithic; Late middle-upper Pleistocene; Acheulian