Redistribution of trace metals in a mineralized spodosol due to weathering, Liikavaara, northern Sweden

Abstract The till east of the Liikavaara Ostra ore deposit in northern Sweden is in some parts rich in Cu and other sulphide-associated metals. Groundwater flowing in this till has higher concentrations of Cu than groundwater in a reference area where the till has low concentrations of Cu and other metals. To understand the processes that release metals from the mineralized till at Liikavaara into the groundwater, the authors performed a detailed study of the 2+ in the biotite through ion exchange with K + may be an important mechanism for Cu-enrichment in biotite at Liikavaara. The airborne dust is not the source of Cu in the till. Although the soil water at Liikavaara has higher concentrations of Cu and other metals than the soil water at the reference area, the Cu-concentration is too low for infiltrating soil water to explain the high Cu-concentrations observed in groundwater. The high metal concentrations in the till, of Cu in particular, cause the increased concentrations in the local groundwater. A fluctuating groundwater table washes out Cu and other metals from the till. It is possible that increased Cu concentration in the local groundwater is caused by dissolved organic complexes, or by colloids (