Using Indicator Kriging for Lead Spatial Patterns Assessment in sediments- the Caveira Mine Case Study Portugal

Abstract

Lead pollution (Pb) is widespread in many mining communities around the world, including in developing countries. Anthropogenic contributions of Pb to the environment are primarily associated with fossil fuel emissions and industrial and mining activities. This study, as part of the GeoMaTre project, an ongoing collaborative network (2021-2024) between the Polytechnic Institute of Castelo Branco and the University of Évora, Portugal, aimed to evaluate the potential risk of lead pollution in stream sediments in the surrounding area of Caveira mine. This mine corresponds to one of the decommissioned mining centers of the Iberian Pyrite Belt, a Europe's leading sulfide mining province, in SW Portugal, and includes large mining wastes piles containing significant amounts of metals, mainly Pb, Cu, Zn and Hg. Although the mine and the larger heap are located on a ridge, the regional drainage is not dispersive and all the streams originating from them, converge into the Ribeira de Grândola, used as water supply for agriculture, livestock and domestic uses. Given their spatial arrangement and greater vulnerability, these tailings are the main source of metals of the stream sediments and determine their chemical signature.