内蒙古大石寨地区稀土元素的区域分布特征
Regional Geochemical Distribution Characteristics of Rare Earth Elements in the Dashizhai Area, Inner Mongolia

摘要： 总结了内蒙古大石寨地区1∶25万区域地球化学调查获得的1点/4km2的水系沉积物组合样品中的La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Ho、Er、Tm、Yb、Lu、Y等15种稀土元素的区域地球化学分布特征。稀土元素分布与研究区中部的黑云母花岗岩密切相关，轻稀土主要分布在该岩体外围的二叠系地层中，重稀土主要分布在该岩体上方。该岩体上方和外围地层的稀土元素分布、稀土元素总量、轻重稀土比及δCe、δEu、(La/Sm)N、(La/Tb)N、(La/Lu)N、(Ce/Yb)N、(Gd/Lu)N等稀土元素分馏特征的差异明显。利用区域地球化学调查水系沉积物样品中的稀土元素含量，可获得研究区可靠的稀土元素区域地球化学分布特征，也可反映研究区地质特点，并为区域地球化学异常解译提供参考资料。
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