An occurrence of naturally lead-poisoned soil at Kastad near Gjøvik, Norway.

Abstract

A 100 m2 area with exeptionally sparse vegetation in the forestat Kastad, 6.5 km north of Gjøvik, Norway, is described. The area bearsno signs of human activity. Determination of heavy metals in the soilsof the area shows no really abnormal contents of V, Mn, Co, Ni, Cu, Mo,Ag, and Zn, but a mean concentration of 4,7% Pb in top soil dry matter.There is a clear correlation between sparsity of vegetation and leadcontent in the soil, and it has been concluded that the area is leadpoisoned. Most plants normally growing in the area were not found onthe lead-rich soils, although some regitered species can tolerateconsiderable lead in the substratum. The vegetation growing on the leadrich soil has an abnormally high lead content, and might therefore havean injurious effect on the fauna. It is presumed that the lead in thesoil is accumulated from natural solutions produced during chemicalweathering of a galena-bearing quartzite. Registration of areas withsparse or selective vegetation might be used as a tool in leadprospecting.