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中国沙漠 ›› 1987, Vol. 7 ›› Issue (1): 24-33.

• 论文 • 上一篇    下一篇

北京地区沙物质的重矿物成分、结构特征与风沙的沙物质来源

宋锦熙   

  1. 中国科学院兰州沙漠研究所
  • 出版日期:1987-03-20 发布日期:1987-03-20

Heavy Mineral Composition Texture and Sources of Blownsands in Beijing Region

Song Jingxi   

  1. Institute of Desert Research, Academia Sinica, Lanzhou
  • Online:1987-03-20 Published:1987-03-20

摘要: 北京地区不同类型的风成沙经重矿物成分、特征进行详细分析鉴定表明,与本区河床沙、平原堆积物和坡积物均很相似,与河床沙更为接近.但与区外沙漠沙丘砂的重矿物成分资料对比,差异较大.研究表明:1)本区河床沙与沙丘沙重矿物含量相对较高;2)本区沙丘沙与河床沙中,辉石,尤其紫辉石含量相对较高;3).本区沙物质中不稳定矿物与较稳定矿物含量高,重矿物磨圆度普遍较差,河床沙与沙丘砂尤为明显;4).本区沙丘沙与河床沙存在着明显的继承关系.故本区风成沙主要来自本区河床沙,风沙的来源区域有限,在治理上应着眼于本区为主。

Abstract: yB analyzing the heavy mineral composition and texture of different aeolian sands in Beijing Region,it is indicated that,in comparison with the data of heavy mineral composition of dune sands of other desert,the aeolian sands in Beijing Region are close to the sands on riverbed,and similar to plain accrmulated materials and to slope wash but are obviously different with the sands of the desert at the outskirt of Beijing Region. Analyses Show: 1) the heavy mineral compositions of sands of riverbed and of dune sand are relative concentrated; 2) high contents of pyroxene and purple pyroxene in the dune Sands and sands of riverbed; 3) high contents of unstable and stable minerals and poor grainness of heavy minerals of dune sands and sands of riverbed; 4) markable inheritances of dun sands and sands of rivereds.lt is concluded that the sand on riverbed is the main source of sandln in Beijing Region. Because of the limitation of sand source,methodologically the control of sand in the reqion should be focused on local scale.