Monitoring the environmental evolution and its relationship with anthropogenic activities using magnetic and geochemical proxies on Lake Melincué sediments

ACHAGA, R.; GOGORZA, C.; IRURZUN, M.A.; GOGICHAISHVILI, A.; MESTELÁN, S.; RUIZ FERNÁNDEZ, A.C.; SÁNCHEZ CABEZA, J.A.; SÁNCHEZ BETTUCCI, L.; SINITO, A.; MORALES, J.; MARTÍNEZ, D.

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2022 vol. 116

0895-9811

Twosediment cores, collected from the centerof the Lake Melincu´ e (Santa Fe, Argentina),were analyzed using rock magneticresults, element composition, Total Organicand Inorganic Carbon (TOC and TIC)and Total Nitrogen (TN) to reconstruct theenvironmental variations in the lastthree centuries, associated with climaticchanges and/or human activities. 210Pbdating, chronostratigraphic markers, andpaleomagnetic results were used tocreate the age model of the cores. Rockmagnetic analyses suggest that(titano)magnetite and a low proportion ofhematite are the main magneticphases. In addition, geochemical results comparedwith rock magnetic analysisindicate the possible presence of diageneticdissolution. Fourwell-differentiated environmental phases were found withvariations from coldto more humid and warmer environmental conditions. Unit 0from 1750 CE to 1783CE with a cold environment and high lake level, Unit 1 from1783 CE to 1878 CEwith continuing cold environmental conditions but a low lakelevel, showing theend of the Little Ice Age (LIA) toward the top, Unit 2 from1878 CE to 1874 CEwith a wetter environment and Unit 3 from 1974 CE to 2016 CEwith wet and warmconditions and a high lake level.