基于DEM的南岭东段离子吸附型稀土矿成矿地貌条件分析

稀土是我国重要的战略资源,而离子吸附型稀土矿是我国的特色矿产,占据着重要的地位。离子吸附型矿产的形成与否,与风化壳密切相关,而风化壳的发育及保存与微地貌等特征密切相关。本文旨在利用DEM技术,结合搜集到稀土矿点及矿区数据,对含有稀土的地貌单元进行地形因子定量分析,以总结风化壳离子吸附型稀土矿的成矿地貌条件。借助GIS技术,利用DEM提取高程、坡度、坡向、曲率、地形起伏度、地表切割深度、地形特征等各类地貌因子值,并与南岭东段的成矿矿点及矿区进行叠加分析,统计计算矿点及矿区所处位置的地貌因子值,进而探讨风化壳型稀土资源赋存的有利地形地貌环境。结果显示,最佳成矿有利地貌为高程150~500 m、坡度0°~20°、地形起伏度100~400 m、地表切割深度40~150 m、地形特征为山顶或山脊;研究结果有望指导南岭东段离子吸附型稀土矿找矿勘查工作。

The Metallogenic Geomorphic Condition Analysis of the Ion-absorbing Type Rare Earths Ore in the Eastern Nanling Region Based on DEM Data

Rare earths are important strategic resources in our country, and ion adsorption type rare earths ore is the characteristics mineral of our country, which occupying an important position. Whether the ion-absorption type mineral deposits can be formed is closed related to the weathering crust, and the development and preservation of weathering crust is subject to micro geomorphology. Therefore, the purpose of this paper is to summarize the weathering crust ion adsorption type rare earth ore metallogenic geomorphic conditions by quantitatively analyzing the terrain factors of geomorphic unit containing rare earth ore under DEM technology, combined with the collected data of rare earth mines and mining area. With the help of GIS technology, terrain elevation, slope, aspect, curvature, surface rolling, surface incision, terrain feature and other kinds of landform factor value were extracted with DEM data. Through the overlay analysis of mineral occurrence and mining area data with the terrain value in the eastern part of Nanling region, the terrain factor value of mineral occurrence and mining area is statistically calculated, and then the geomorphic environment hosting weathering crust type rare earths ore is discussed. The results show that the favorable landscape for REE mineralization is the elevation of 150 ~ 500 m, the slope of 0° ~ 20°, the surface rolling of 100 ~ 400 m, the surface incision of 40~150 m, and the terrain feature of the peak or ridge. The results of the study is expected to guide ion adsorption type rare earth ore prospecting exploration in the east of Nanling region.