Abstract: The Huashilang Longyadong Cave site along with open-air sites of Paleolithic were identified for the first time, and then excavated and investigated during 1995-1999 in the Luonan Basin, Luonan county, Shaanxi province, China.More than 2 000 stone artifacts were collected from the 50 open-air sites and about 20 species animal fossils along with 65000 artifacts were excavated from the Longyadong cave. This paper provides a preliminary study of site formation of lithic-stratigraphy in their geological context as well as results of TL dating.
Supported by relationship of the 8 strata, three cultural periods were divided in the Longyadong cave site.In the first period, humans lived in the river bank; In the second period, they lived in the cave and on the terrace, the climate was dry and cold; The third period was a main deposit time in the Longyadong cave site, most artifacts and ash layers were identified in this period, the climate was warm and moist.After that time, no hominid remains were identified.
The five samples of the TL dates (three from the cave site and the other two from the Zhoupo open-air site 95LP07)place the site into the middle to late period of the Middle Pleistocene (Q2 2—3). The three samples in the Longyadong cave site were collected from the third middle period of the inner cave and the upper layer of the outer cave.The two TL dates from inner cave are 356.6 ±17.8ka and 273.9 ±13.7ka respectively, and another from the outer cave is 210.5 ±10.5ka.It is suggested that the early hominids left this site about 250ka ago because no cultural remains were found both in the inner cave and the upper layer of the slope deposits of the outer cave.The other two samples from upper layer of the Zhoupo site are 251.05 ±12.5ka and 182.8 ±9.1ka respectively.
Compared the TL dates with the stratigraphic data of Zhou-koudian Peking Man site, loess depos- its in the Shaanxi Luochuan, the red earth in Anhui and deep-sea records, the dates of the sites we are dealing with in this article are in range of about 500-250 ka, which is in the same timeframe of Zhoukoudian Peking Man site.Therefore, culturally the sites can be suggested to be Early Paleolithic.

Key words: Stratigraphy; TL Dating; Paleolithic; Luonan Basin