摘要
中国以水系沉积物测量为主的区域地球化学调查自1978年开始以来,已覆盖陆地面积约690×10~4 km^2,积累了海量的高质量基础地球化学数据.在这些数据的开发利用中不同地区、不同范围间的数据对比是研究元素分散富集、成矿趋势、异常评价的一项重要内容.以全国1∶20万水系沉积物测量数据为依据,采用全部原始数据,以X±3S为临界值一次性剔除异点后的数据集的中位数作为背景值的估计值,使用统一方法计算出了全国范围、9个大地构造单元、12个地球化学景观区、19个成矿带的39种元素水系沉积物背景值,探讨了全国范围、不同构造单元、不同景观区、不同成矿带各元素背景值的区域分布规律和特征.研究表明不同的景观区、不同的成矿带、不同的大地构造单元,由于地质背景和景观条件不同,元素的地球化学分布特征也不同,表现出不同的区域分布特点和分布模式.这些背景值为进一步深入开发利用区域化探数据和资料提供了可供对比的基础数据.
Large amounts of high quality basic geochemical data covering a land area of about 6 900 000 square kilometers have been gained by regional geochemical survey mainly featuring stream sediment measurement since 1978 in China.The development and utilization of the comparative data in different areas and different ranges is an important part of the research of dispersion of element enrichment,metallogenic tendency,and anomaly evaluation.Based on the total original data of the national 1∶200 000 stream sediment survey,background values of 39 elements in stream sediments are calculated for the nationwide 9 tectonic units,12 landscape areas and 19 metallogenic belts.The median of the data set after disposable eliminating outliers from a data population with X±3 Sas the critical value is used as an estimate value of geochemical background values.Different element distributions and characters of background values of the nationwide tectonic units,landscape areas and metallogenic belts are discussed.The results show that geochemical distributions of elements are different among various landscapes,metallogenic belts and tectonic units because of different geological backgrounds and landscape conditions.It shows there are different regional distribution characteristics and the different distribution patterns.These background values can be used as basic data for comparison for further development and utilization of regional geochemical data.
出处
《地球科学（中国地质大学学报）》
EI
CSCD
北大核心
2016年第2期234-251,共18页
Earth Science-Journal of China University of Geosciences
基金
地质矿产调查评价专项计划项目
