Abstract: Based on the regional geochemical survey, stream sediment sampling and analysis, the REE distribution characteristics of the stream sediments from the Dashizhai area in Inner Mongolia were evaluated systematically. Results show that ΣREE, ΣLREE/ΣHREE, δCe, δEu, (La/Sm)N, (La/Tb)N, (La/Lu)N, (Ce/Yb)N and (Gd/Lu)N of stream sediments have significant differences from the biotite granite in the central part of the study area and strata around the biotite granite. The REE distribution is closely related to the biotite granite; light rare earth elements are mainly distributed in the periphery of the biotite granite, and heavy rare earth elements are mainly distributed in the top of that biotite granite. The REE concentration of stream sediments from regional geochemical survey can reasonably describe the REE distribution, and can reflect the geological characteristics of the survey area, thus can provide references for the interpretation of regional geochemical anomalies.

Key words: regional geochemical survey, stream sediment, rare earth element, Dashizhai area, interpretation of anomaly