关键词: 光释光测年；旧石器时代中期；三峡地区；井水湾

Abstract: The Jingshuiwan Paleolithic site, buried in the second terrace of the right bank of the Yangtze River, is located in the Xinwan village, Sanhe town, Fengdu county, Chongqing. The site was excavated from 1998 —2002 for five successive seasons, exposing an area of about 2 121m2, as past of the salvage archeological project in the Three Gorges Region.
Seven stratigraphic layers were identified at the site, with the total thickness of more than 21 meters. Archaeological materials were mainly unearthed from the 7th layer, a layer of fine sands, 2.0m in thickness, 158—162m above the sea-level, in clear primary context. A total of 910 stone artifacts and some mammalian teeth and bones,including Stegodon, Cervids and Bovids,were unearthed from the site.
The stone assemblage includes cores (304), flakes (382), stone hammers (4), chunks (102) and retouched tools (118). The general features of these artifacts are summarized as follows:
1)Stone raw materials exploited at the site were locally available from ancient riverbeds. More than 5 kinds of raw material were utilized in core reduction and tool manufacture: silicarenite, quartzite, hypabyssal irruptive rock, volcanic rock and volcanic breccia lava. Silicarenite is the predominant raw material used for producing stone artifacts at the site.
2)The principal flaking technique at the site is direct hammer percussion without core preparation.
3)About 7. 6 percent of flakes could have been utilized directly without modification.
4)Major blanks for tool fabrication are complete flakes (67.0 %), followed by cores and incomplete flakes.
5)Most tools are large and middle in size.
6)Choppers and scrapers are the dominating tool types, followed by points and notches.
7)Modified tools appear to be retouched by direct hammer percussion, mostly unifically retouched on the dorsal surface of blanks.
The Jingshuiwan stone tool assemblage shows close tie with the Main Industry in South China. Comparative studies indicated that it might serve as a technological link between Paleolithic industries from the Sichuan Basin and that from the lower reach of the Yangtze River.
Environmental analyses conclude that hominids at Jingshuiwan site were living in warmmoist climatic condition, indicated by the existence of coniferoustrees, broad-leaf trees, and mixed forest-prairie vegetations. Optically Stimulated Lumininescene dating on soil samples that from the artifact-bearing layer has yielded an age close to 80, 000 B. P., which place the Jingshuiwan industry to the Middle Paleolithic in China.

Key words: OSL dating; Middle Paleolithic; Three Gorges region; Jingshuiwan