Historical mercury trends recorded in sediments from the Laguna del Plata,Córdoba, Argentina. Chemie der Erde / Geochemistry. DOI: 10.1016/

STUPAR Y.; J. SCHÄFER,; M.G GARCÍA, ; S. SCHMIDT, ; E. PIOVANO, ; G. B, F. HUNEAU, ; P. LE COUSTUMER

CHEMIE DER ERDE

ELSEVIER GMBH, URBAN & FISCHER VERLAG

Año: 2014 vol. 74 p. 253 - 263

0009-2819

Atmospheric transport and exchange at the air-water interface play an important role in the global mercury cycle where sediments can act as effective traps for this metal. The work performed here has the objective to identify the main carrying phases of mercury in a 120 cm sediment core taken at the Laguna del Plata (LP). This small lake is connected to the main water body of Mar Chiquita Lake (MCL) during highstands. MCL is considered to be one of the biggest saline lakes in the world representing a sensitive climatic indicator due to its abrupt lake level variations that started early in the 1970s. Total mercury (Hg TP) concentrations vary between ~13 and ~131 µg/kg indicating a system with low pollution. Selective extractions with ascorbate, HCl and H2O2 were performed in the sediments and they revealed that Hg is associated in the base of the core, mainly to reactive sulfides while in the middle and upper part the organic matter seems to be the main carrier. The highest and most important peak could be related to natural origin as the eruption of Hudson volcano in 1991 in the southern part of the Andes Range instead to a punctual source of pollution.