Mercury and REE contents in fruticose lichens from volcanic areas of the south volcanic zone

PEREZ CATAN, S.; BUBACH, D.; MESSUTI, M.I.; ARRIBIERE, M.A.; RIBEIRO GUEVARA, S.

Atmospheric Pollution Research

Elsevier

Año: 2022 vol. 13 p. 1 - 7

1309-1042

Volcanic eruptions represent one of the natural sources of Hg along with evasion from the oceans. The Argentinean Andean Patagonia has been impacted by volcanic emissions from the Chilean Andes facilitated by western winds blowing from the Pacific Ocean. This work evaluates the influence of these sources in the Hg bioaccumulation by fruticose lichens sampled from nearby sites affected by recent volcanic activity in the Patagonia Andean range. This was accomplished by using geological techniques such as the study of REE and multi-element patterns to identify the source of the tephra layers. The ?spider patterns? diagrams of lichen multi-element concentration normalized to references values and also REEs ratios (LREE/MREE and LREE/HREE) and Eu/Eu* anomalies were used. Furthermore, the relationships among Hg and others volatile and semi volatile elements with the distance to the emitting points were considered. In general, the results found in the lichens were in agreement with the provenance of glass fractions from volcanic eruptions in the influenced zone. The diagrams of lichen multi-element concentration showed similar patterns for lichens taken from locations in the further south (near to Hudson volcano) which were different from the lichens taken from the northern area (near to Puyehue, Calbuco and Copahue volcanoes). The average values of LREE/MREE showed similar values in lichen samples taken from the north and south areas from Puyehue Cordon Caulle Volcanic Complex and the ranges of the volcanic glass particles expelled during the 2011 eruption. The lichens from the middle area show REE ratios and Eu anomalies similar to the glass fractions emitted by Chaiten Volcano near to them. The results suggest that normalized patterns of the REEs in fruticose lichens might provide a proxy record of the elements released from a volcanic source. Correlations of concentration of semi volatile elements to the volcanic distances and to the Pacific Ocean showed Hg and Sb bioaccumulated in lichens had one or both contribution depending on the Andes altitudes.