物探与化探2025，Vol.49Issue(2)：270-280,11.DOI:10.11720/wtyht.2025.2571
德昌地区水系沉积物稀土氧化物总量地球化学特征及找矿方向
Total rare-earth oxides in stream sediments in the Dechang area:Geochemical characteristics and prospecting targets
摘要
Abstract
The Mianning-Dechang area in western Sichuan serves as the most important metallogenic belt of light rare earth elements(LREEs)in China.To make breakthroughs in the exploration of rare earth resources in the Dechang area,a 1∶50 000 stream sedi-ment survey was conducted in this study.The analysis of test data characteristics and the extraction of geochemical anomalies reveal that the total rare-earth oxides(REOs)in the area exhibit a pronounced enrichment pattern and that element anomalies largely overlap the spatial distribution of related geological bodies.Through comprehensive analysis using the cumulative frequency method and itera-tive method,this study determined the lower limits of anomalies and,accordingly,plotted element anomaly maps,with five main a-nomaly areas being delineated.The comprehensive evaluation of anomalies revealed four prospecting target areas:Huangjiaba,Jiaoba-cun,Yibasan,and Huajiaoyuan.The analysis of metallogenic geological conditions and the anomaly verification based on drilling in the Gannan area led to the discovery of three light rare earth deposits in the Huangjiaba prospecting target area,two heavy rare earth depos-its in the Jiaobacun prospecting target area,two heavy rare earth deposits in the Yibasan prospecting target area,and two heavy rare earth deposits in the Huajiaoyuan prospecting target area.This study posits that the Triassic biotite moyite and biotite monzogranite in the study area are the metallogenic parent rocks of ion adsorption-type rare earth resources,with REEs primarily undergoing enrichment and mineralization in completely weathered layers.Therefore,a simple and effective prospecting pattern for"endogenous and exoge-nous"ion adsorption-type rare earth deposits in the Dechang area consists of analyzing the geochemical characteristics of the total REOs based on a 1∶50 000 stream sediment survey,delineating metallogenic prospect areas that indicate parent rocks for REE enrichment,and selecting sections favorable for the formation and preservation of weathered crusts based on the hypergenic conditions of the enrich-ment areas,thus achieving the quick delineation of the prospecting target areas.关键词
德昌/水系沉积物/稀土氧化物总量/地球化学Key words
Dechang/stream sediment/total rare-earth oxide/geochemistry分类
天文与地球科学引用本文复制引用
朱友欢,聂飞,邹佳作,李宏伟,周学铖,冉光辉,雷栋..德昌地区水系沉积物稀土氧化物总量地球化学特征及找矿方向[J].物探与化探,2025,49(2):270-280,11.基金项目
中国地质调查局项目"攀西冕宁—德昌地区稀土及多金属矿产地质调查"(DD20220965) （DD20220965）
