OSMIUM IS ANCIENT MARKER

Abstract

EVIDENCE OF ANCIENT human activity can be gleaned from the concentrations of the rare element osmium in peat core samples, a new report shows. The finding suggests that osmium could be used to discover and date past human industrial activities. An international team led by Sebastien Rauch at Chalmers University of Technology, in Sweden, shows that 4,700 years ago technologies such as mining and smelting affected the distribution and concentration of osmium in peat bogs in the Xistral Mountains of northwest Spain ( Environ. Sci. Tech. , DOI:10.1021/es901887f). Next to iridium, osmium is the least abundant element in Earth’s crust. But it can be emitted as a by-product of processes such as mining or smelting. Scientists have already discovered that some modern human technologies, including the use of automobile catalytic converters, have concentrated osmium in some areas. “In a period when we are focusing on major emissions— greenhouse gases—this study shows that human activities also affect ...