2. 河南省地球化学生态修复工程技术研究中心，郑州450001;

3. 河南省地质矿产勘查开发局第二地质环境调查院，郑州450001

了其地球化学基线值，并结合地累积指数法对研究区不同类型土壤重金属累积程度进行了评价。结果

表明: 永城市表层土壤As、Cd、Cr、Cu、Ni、Pb、Zn 的基线值分别为11. 81、0. 183、65. 96、24. 79、32. 62、24. 74 和71. 15 mg·kg － 1。地累积指数法评估表明全区样品以无累积为主，Cr、Ni 的样点全为无累积; As、Cd、Cu、Pb、Zn 的无--中度累积的样点数分别为4. 17%、2. 84%、1. 33%、0. 57%及0. 19%，且Cd 存在一个中度累积样点。各元素在砂姜黑土及碱土中均为无累积水平，壤质潮土、黏质潮土中存在无--中度累积的样点。

2. Henan Geochemical Ecological Ｒestoration Engineering Ｒesearch Center，Zhengzhou 450001，China;

3. No. 2 Institute of Geo-environment Survey，Bureau of Geology and Mineral Exploration and Development of Henan Province，

Zhengzhou 450001，China

accumulative index． The results showed that the mean baseline values of As，Cd，Cr，Cu，Ni，Pb and Zn in surface soils in Yongcheng were 11. 81，0. 183，65. 96，24. 79，32. 62，24. 74 and 71. 15 mg·kg － 1，respectively．The geological accumulation index indicated that the seven heavy metals in the most surface soils of Yongcheng were at uncontaminated level，and the samples of Cr and Ni are all uncontaminated． The proportions of no accumulation

or moderate accumulation of As，Cd，Cu，Pb and Zn are 4. 17%，2. 84%，1. 33%，0. 57% and 0. 19%，respectively，and there is a moderate accumulation point in Cd． Every element in lime concretion black soil and alkaline

soil had no accumulation level，and there were no accumulation or moderate accumulation sample in loamy and clayey fluvo-aquic soils．