High-altitude cushion peatlands as sentinels of Holocene environmental changes in the Central Andes (NW Argentina)

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Being located at the crossroads between tropical and extra-tropical precipitation regimes, the southern Central Andes are a key area for palaeoclimatic studies. Our preliminary investigations show that highaltitude cushion peatlands are extremely well-suited for palaeoecological multi-proxy studies. The strengths of these geoarchives are their comparability over climatic gradients, their high accumulation rates and the high quality of their peat deposits to be precisely 14C-dated. Previous palaeoenvironmental investigations in the area on lake sediment archives and fossil rodent middens lack continuity or comparability due to the selection of heterogeneous locations and methods. We propose to carry out a late Pleistocene/Holocene vegetation and climate reconstruction based on a multi-proxy approach (micro-/macrofossils, isotope analysis, geochemical analysis, sedimentology) from peat sediment cores. Geoelectrical earth resistivity tomographies, verified with selective coring, will offer an insight into the structural build-up of the peatlands, which, so far, lack scientific geomorphological description and characterization. The expected results will not only contribute to the controversial discussion whether the middle Holocene in these latitudes was arid or humid, they will further offer palaeoclimatic variabilities, which are indispensable for comparison with continent- or global-scale, high-resolution palaeoclimate records.