In response to the performance of the Global Goochomical Sampling (a subproject of the IGCP Project 259, International Geochemical Mapping), an orientation study was conducted in 1989-1990 to develop an optimum wide-spaced geoehemical sampling approach in Jiangxi Province, Southsart China. 121 overbank sediment samples were collected in an area of about 157,000 km2, with the average sampling density being 1 sample/1,300 km2, and the sampling coverage being 24%. Most of the samples were collected at outflow sites of the drainage basins with an area of 100-500 km2, including 33 samples that control basins of 400-2,000 km2.Overbank sediment samples were taken at a dspth of 50-120 cm, and the samples were analyzed quantitatively for 38 elements. The representativeness of wide-spaced overbot sediment sampling is discussed from vinous angles in the paper, with tho following conclusions reached:-Sampling at the outflow areas of 400-2,000 km2 drainage basins can reveal the major minoralizations in the basins;-W, Sn, Cu. Pb and Zn in both wide-spaced samples and drainage sediment samples collected at a density of a samples/km2 manifest similar regional geochemical trends;-Distribution of W, Pb, Be and Rb coincides with the Yanshanian graftes closely related to the major ore-forming plocesses in Jiangxi;-Distribution of "3Ni +Cr + V" in wide-spaced samples can distinctly reveal the boundary between the Yangtze paraplatform and the Caledonian fold symbol in Jiangxi.
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