Mercury pollution in a large marine basin: a natural venting system in the south-west Mediterranean margin

Abstract

The Mediterranean basin is characterized by the existence of a geological anomaly of large cinnabar deposits which are part of a mercury-containg belt that encircles the Earth, and lies mainly in the area of Spain, Tunisia, Italy, Slovenia, and Turkey. In fact, approximately 65% of the world's mercury resources are contained in the Mediterranean basin. Recently, the influence of these mineralized areas on mercury contamination has been estimated, and indicates the significance of the Almaden mineral deposits (the largest producer of mercury in the world). Nevertheless, this mercury district - located almost 400 km away from the Mediterranean coastline does not greatly participate in the mercury pollution of the Mediterranean basin. There are, however, two previously unknown mercury-bearing mineralized areas - Las Herrerias and Valle del Azogue - which have not been taken in to account in the mercury pollution of the south-west Mediterranean margin.