Change search
ReferencesLink to record
Permanent link

Direct link
Climate induced changes as registered in inorganic and organic sediment components from Laguna Potrok Aike (Argentina) during the past 51 ka
Show others and affiliations
2013 (English)In: Quaternary Science Reviews, ISSN 0277-3791, Vol. 71, 154-166 p.Article in journal (Refereed) Published
Abstract [en]

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 (SHIN) 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. (c) 2012 Elsevier Ltd. All rights reserved.

Place, publisher, year, edition, pages
2013. Vol. 71, 154-166 p.
Keyword [en]
Carbonates, Organic matter, Biogenic silica, Diffuse Reflectance Fourier Transform, Infrared Spectrometry (DRIFTS), Lake level, Primary productivity, Patagonia, Argentina, ICDP project PASADO
National Category
URN: urn:nbn:se:umu:diva-79266DOI: 10.1016/j.quascirev.2012.09.015ISI: 000321178500013OAI: diva2:645323
Available from: 2013-09-04 Created: 2013-08-13 Last updated: 2013-09-04Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Rosen, Peter
By organisation
Department of Ecology and Environmental Sciences
In the same journal
Quaternary Science Reviews

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 40 hits
ReferencesLink to record
Permanent link

Direct link