Holocene environmental changes in the highlands of the southern Peruvian Andes (14° S) and their impact on pre-Columbian cultures

• DOI: 10.5194/cp-11-27-2015
• Publication Date: 2015-01-07T08:37:39Z
• Authors: K. Schittek; M. Forbriger; B. Mächtle; F. Schäbitz; V. Wennrich; M. Reindel; B. Eitel
• Keywords: Phytolith

Abstract. High-altitude peatlands of the Andes still remain relatively unexploited although they offer an excellent opportunity for well-dated palaeoenvironmental records. To improve knowledge about climatic and environmental changes in western southern Peru, we present a high-resolution record Cerro Llamoca peatland last 8600 years. The 10.5 m long core consists peat intercalated sediment layers was examined all kinds microfossils. We chose homogeneous sections pollen analysis at decadal to centennial resolution. inorganic geochemistry analysed 2 mm resolution (corresponding >2 years) using ITRAX X-ray fluorescence scanner. interpret phases high abundances Poaceae our as expansion Andean grasslands during humid phases. Drier conditions are indicated by significant decrease higher Asteraceae pollen. results substantiated arsenic contents manganese/iron ratios, which turned out be applicable proxies situ palaeoredox conditions. mid-Holocene period 8.6–5.6 ka is characterised series episodic dry spells alternating with that more humid. After pronounced 4.6–4.2 ka, generally shifted towards climate. stress humid/relatively stable interval between 1.8 1.2 coincides florescence Nasca culture foothills. An abrupt turn sustained occurs contemporaneous demise Nasca/Wari society Palpa lowlands. Markedly drier prevail until 0.75 providing evidence presence Medieval Climate Anomaly. Moister but hydrologically highly variable prevailed again after allowed re-expansion tussock grasses highlands, increased discharge into foreland resettling lowlands this so-called late Intermediate Period (LIP). On supraregional scale, findings can ideally linked proved archaeological chronology Nasca–Palpa region well other marine terrestrial Our show hydrological fluctuations, triggered changing intensity monsoonal tropical summer rains emerging from Amazon Basin north-east, have controlled climate study area.