(Table 1) Major element composition of core 5022-2CP, Laguna Potrok Aike, southern Patagonia


Total organic carbon, total inorganic carbon, biogenic silica content and total organic carbon/total nitrogen ratios of the Laguna Potrok Aike lacustrine sediment record are used to reconstruct the environmental history of south-east Patagonia during the past 51 ka in high resolution. High lake level conditions are assumed to have prevailed during the Last Glacial, as sediments are carbonate-free. Increased runoff linked to permafrost and reduced evaporation due to colder temperatures and reduced influence of Southern Hemispheric Westerlies (SHW) may have caused these high lake levels with lake productivity being low and organic matter mainly of algal or cyanobacterial origin. Aquatic moss growth and diatom blooms occurred synchronously with southern hemispheric glacial warming events such as the Antarctic A-events, the postglacial warming following the LGM and the Younger Dryas chronozone. During these times, a combination of warmer climatic conditions with related thawing permafrost could have increased the allochthonous input of nutrients and in combination with warmer surface waters increased aquatic moss growth and diatom production. The SHW were not observed to affect southern Patagonia during the Last Glacial. The Holocene presents a completely different lacustrine system because (a) permafrost no longer inhibits infiltration nor emits meltwater pulses and (b) the positioning of the SHW over the investigated area gives rise to strong and dry winds. Under these conditions total organic carbon, total organic carbon/total nitrogen ratios and biogenic silica cease to be first order productivity indicators. On the one hand, the biogenic silica is influenced by dissolution of diatoms due to higher salinity and pH of the lake water under evaporative stress characterizing low lake levels. On the other hand, total organic carbon and total organic carbon/total nitrogen profiles are influenced by reworked macrophytes from freshly exposed lake level terraces during lowstands. Total inorganic carbon remains the most reliable proxy for climatic variations during the Holocene as high precipitation of carbonates can be linked to low lake levels and high autochthonous production. The onset of inorganic carbon precipitation has been associated with the southward shift of the SHW over the latitudes of Laguna Potrok Aike. The refined age-depth model of this record suggests that this shift occurred around 9.4 cal. ka BP.

DEPTH, sediment is given in meters composite depth (mcd). Age data is calibrated with CalPal applying the 2007_HULU calibration curve; PASADO age model V.3.

Supplement to: Hahn, Annette; Kliem, Pierre; Ohlendorf, Christian; Zolitschka, Bernd; Rosén, Peter; PASADO Science Team (2013): Climate induced changes as registered in inorganic and organic sediment components from Laguna Potrok Aike (Argentina) during the past 51 ka. Quaternary Science Reviews, 71, 154-166

DOI https://doi.org/10.1594/PANGAEA.808196
Related Identifier https://doi.org/10.1016/j.quascirev.2012.09.015
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.808196
Creator Hahn, Annette (ORCID: 0000-0002-3647-473X); Kliem, Pierre; Ohlendorf, Christian ORCID logo; Zolitschka, Bernd ORCID logo; Rosén, Peter; PASADO Science Team
Publisher PANGAEA
Publication Year 2013
Rights Creative Commons Attribution 3.0 Unported; https://creativecommons.org/licenses/by/3.0/
OpenAccess true
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 8787 data points
Discipline Earth System Research
Spatial Coverage (-70.376 LON, -51.971 LAT); Laguna Potrok Aike, Patagonia
Temporal Coverage Begin 2008-10-29T00:00:00Z
Temporal Coverage End 2008-11-17T00:00:00Z