地理学报 ›› 1999, Vol. 54 ›› Issue (5): 438-444.doi: 10.11821/xb199905007

• 论文 • 上一篇    下一篇

岩溶动力系统中的元素迁移

蒋忠诚   

  1. 国土资源部岩溶地质研究所,广西桂林541004
  • 收稿日期:1998-05-08 修回日期:1999-04-23 出版日期:1999-09-15 发布日期:1999-09-15
  • 基金资助:
    国家自然科学基金项目(49632100与49872096);地质行业基金项目(HY979823)

Element Migration of Karst Dynamic System

JIANG Zhong cheng   

  1. Institute of Karst Geology, Guilin 541004
  • Received:1998-05-08 Revised:1999-04-23 Published:1999-09-15 Online:1999-09-15
  • Supported by:
    National Natural Science Foundation of China,No.49632100 and 49872096&Geological Foundation of China,No.HY979823

摘要: 碳- 水- 钙循环构成的岩溶动力过程驱动岩溶环境的元素迁移, 并制约元素迁移的质和量。在弱岩溶动力作用下, 可溶性元素迁移, 难溶元素在环境中相对富集; 在强岩溶作用条件下, 岩石的碳酸盐成分迅速溶解并以很高的浓度迁移, 难溶的 Fe、 Si、 Al、 P、 M n 元素在岩溶水中也有一定的含量, 因此元素迁移对岩溶动力条件具有敏感性。碳酸盐岩背景的元素迁移造成富钙的环境, 由此影响其它元素的迁移, 但岩石中元素的高背景值仍可促进生态环境中该类元素的富集。

关键词: 元素迁移, 岩溶动力系统, 岩溶环境

Abstract: Abstract The cycle of CO2-vater-calcium in the karst dynam is system is able to drive the elementmigration of the karst environments The element migration can be divided into foiw and migration of elements and backw and migration of elements When karst dynamic system gainCO2from ahnosphere or soilair, afonvard migration of element soccurs with the dissolution of the carbonate rocks in water. If some carbon dioxide escapes from thewater, a backw and migration of elements occurs with the depo sition of calcium carbonate. The ellementmigration in karst area is sensitive to the variation of the karst dynamic conditions CO2 content in soil varies with seasons With the increase of CO2 content in soil, pHvalue of water gets down, and Ca2+ (also Mg2+ in dolomite) content in karst water increases Under the waim and humid environments, karst dynam is conditions exihitites strongly, and a high solution rate occurs, then soluble CaCO3 and CaMg(CO3)2 in rocks can be dissolved quickly. As a result, there is lower Ca and Mg content in soil than that in semiarid area.For example, Ca0 and MgO contents in soil in Guilin are only 1 .51% and 1.13% respectively, b u t in Beijing, they are 8.34% and 4.34%. This regulation can be extended to deep soi1s. The higher solution rate, the stronger element migration happens There are different element m igration features in different vegetation conditions. For example, the content of trace elements in karst water is low in bare rock area, but the content of trace elements in karst water in the dense forest ismuch higher. The highest temporary hardness of spring water in the dense forest can reach 19 German degree, and the insoluble Fe, Si, A1, CoandMn can also be partly dissolved into karst water. The geochem ical background of rocksplay an important role in the elementm igration of the environments Ca (also M gin dolour ite) content in the carbonate rocks is high, so the karst areas becom a calcium-rich and a little alkaline geochem ical environm ents with elementmigration. For examp1e, there are calcareous soi1 where its chemical composition has a close relation with the karst processes, high hardness karst w ater, and enriched calcium trees The element migration processes are not same in different carbonate rocks. There is a higher karst water hardness in dolourite than that in linestone, And the maimconstituents and some trace elements increasewith the depth in soilof dolomite area, but no gradual change law of elements in soilprofile of limestone area. The relative abundant background value of trace elements in the argillaceous and silicaeous carbonate rocks also can result in the relative high m ineral nutritious elements in water, soil and vegetation.

Key words: elementmig ration, Karst dynamic system, Karst environment

中图分类号: 

  • P642.25