The evolution of the floodplains of the Yellow and Huan Rivers in North Central China during the Holocene has profoundly influenced the location of major habitation sites, the extent of their preservation, and the challenge of locating buried sites. The case of the Yellow River floodplain is the more dramatic. There, large scale channel migration co-acting with extended periods of minimal alluviation [a stable landscape], alternating with rapid and deep alluviation [not conducive to hosting major city sites], has produced a broad, laterally-changing stratigraphy over a large area. Although in less dramatic fashion, the smaller Huan River floodplain has evolved with a similar pattern. In seeking to locate Shang Dynasty and later sites buried up to 12 meters core drilling has been used to unravel the impact of changing fluvial environments on habitation sites. The location and analyses of paleosols and the contrasting characteristics exhibited by the paleosols and associated archaeological sediments inside and outside of buried walled cities have resulted in our locating two significant 'lost' cities - an Eastern Zhou city in the Shangqiu area [Yellow River floodplain] and Huanbei Shang City near Anyang [Huan River floodplain]. Both lie in Henan Province. The latter fills a substantial chronological gap in the sequence of major Shang sites.