黔北岩溶区土壤地球化学特征及环境质量评价

Pedogeochemical Characteristics and Environmental Quality Evaluation in Qianbei Karst Area

为探明贵州岩溶峰丛山区石灰土的地球化学特征及环境质量,以乌江下游石渡至黄家坪段岩溶区不同时代的石灰土为样本,进行调查、采样、检测、分析及质量评价。结果表明:石灰土质地疏松,受异源母质影响轻微,母质特性明显,其中P2w、P1q石灰土熟化度高,富铝化程度高,质地粘重;元素的迁移流失、亏损(占78%)是山区碳酸盐岩风化成土的主要特征。土壤营养元素综合评级为丰富级,其中,Fe2O3、Ni、Al2O3均丰富,MnO、Na2O、Co、Zn普遍贫乏至严重贫乏;超标危害元素为Cd,属重度超标级,分布于P2w、P1q石灰土中,来源于P2w地层底部煤系层中的富Cd元素。

To explore the pedogeochemical characteristics and environmental quality of Guizhou typical karst mountain area,the lime soil samples collected in Wujiang downstream from Shidu to Huangjiaping with different age,were analyzed and evaluated.The results showed that the soil texture of lime soil was loose with less influence of heterogenous parent material.The parent material features were significant. the soils of P2 w and P1 q were of high ripening degree,high fersialitization degree and heavy texture;The weathering and pedogenesis of carbonate rocks were mainly characterized by migration,run off and loss （78%）of elements.The comprehensive evaluation degree of soil nutrient elements was richness.Fe2 O3 , Ni and Al2 O3 were rich,while MnO,Na2 O,Co and Zn ranged from poor to serious poor;severely overproof element Cd distributed in P2 w and P1 q soils and originated from coal series in the bottom of P2 w stratum.