摘要:
我国西南喀斯特区石漠化分布广泛,其中贵州省石漠化发育尤为严重,对当地生态环境安全造成了严重威胁。为阐明基岩风化成土过程与石漠化发育程度之间的内在关系,对贵州省石漠化地区不同程度石漠化剖面的主微量元素含量及迁移演化规律、矿物组成特征、风化成土能力等因素进行了综合分析研究。结果表明: 石漠化地区成土物质是碳酸盐岩中易溶物质溶蚀及酸不溶物质在原地不断残积的结果; 不同程度石漠化剖面均处于高等风化程度,剖面矿物风化趋势也呈现出石漠化程度越高,土壤层风化程度越高的现象; 石漠化的发育与基岩风化成土过程中元素的迁移方式密切相关,碳酸盐岩基岩中易溶元素含量越高,基岩风化产生的残余成土物质越少,石漠化发育程度越高。通过分析石漠化区的基岩风化地球化学过程及生态地质效应,可以为石漠化成因机理的研究提供参考,对于石漠化治理、促进区域经济可持续发展也具有重要意义。
Abstract:
Rocky desertification is widely distributed in karst areas of Southwest China, especially in Guizhou Province, posing a serious threat to the local ecological environment security. In order to clarify the internal relationship between the bedrock weathering and the degree of rocky desertification, the authors in this paper comprehensively analyzed the content of major and trace elements and the law of migration and evolution, mineral composition characteristics, and the ability of weathering and soil formation for the rocky desertification sections with different desertification degree in Guizhou Province. The results show that the soil material in rocky desertification area is the result of soluble material dissolution in carbonate rocks and the continuous accumulation of acid insoluble material in situ. The rocky desertification sections with different degrees are in a high degree of weathering, and mineral weathering trend in sections, also shows that the higher the degree of rocky desertification, the higher the degree of soil layer weathering phenomenon. The development of rocky desertification is closely related to the migration model of elements in the process of bedrock weathering. The higher the content of soluble elements in carbonate bedrocks, the less the residual soil material produced by bedrock weathering, and the higher the development degree of rocky desertification. The analysis of the geochemical characteristics of bedrock and ecological geological effects of weathering in the rocky desertification area could provide some references for the study of the genetic mechanism of rocky desertification, and is also of great significance to the rocky desertification controlling and the promotion of the sustainable development of regional economy.
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