LOCATION AND GEOGRAPHICAL SETTING

The mound of Zhongba (also known as Yangziyan) is located in group 1 of Youxi Village, Ganjing Township (37°17′14″ N, 108°1′16″ E), a little over 6 km from the confluence of the Ganjing and Yangzi rivers along a meandering river with steep slopes (Beijing ; Sichuan and Chongqing n.d.; Sichuan and Zhong 2001; Sichuan et al. 2007; Sun 1999, 2003a, 2003b, 2008; Sun and Chen 2000; Zhongguo1990). Figure 4.1 shows the locations of Zhongba on the Ganjing River and the sites along the Yangzi near the mouth of the Ganjing: Dujiayuanzi, Wazhadi, Shaopengzui, and Yajiao (Banbianjie and Luojiaqiao). After the construction of the Three Gorges Dam, the Ganjing River valley has been flooded as part of the new reservoir, submerging the Zhongba mound. Prior to this, the Zhongba mound rose over 15 m from the bottom of the meandering Ganjing River valley, just below a precipitous defile, where a slight meander in the Ganjing River is joined by a series of small tributary streams and creeks on both the right and left banks. Although both banks of the river contain some cultural remains (the total site area is about 50 ha in size), the majority of preserved strata identified by archaeological research were located on the northwestern end of an earthen mound (see Figure 4.2).