Multiple landslide clusters record Quaternary climate changes in the northwestern Argentine Andes

Abstract

The chronology of multiple landslide deposits and related lake sediments in the semi-arid eastern Argentine Cordillera suggests that major mass movements cluster in two time periods during the Quaternary, i.e. between 40 and 25 and after 5 ¹⁴C kyr BP. These clusters may correspond to the Minchin (maximum at around 28–27 ¹⁴C kyr BP) and Titicaca wet periods (after 3.9 ¹⁴C kyr BP). The more humid conditions apparently caused enhanced landsliding in this environment. In contrast, no landslide-related damming and associated lake sediments occurred during the Coipasa (11.5–10 ¹⁴C yr BP) and Tauca wet periods (14.5–11 ¹⁴C yr BP). The two clusters at 40–25 and after 5 ¹⁴C kyr BP may correspond to periods where the El Niño–Southern Oscillation (ENSO) and Tropical Atlantic Sea Surface Temperature Variability (TAV) were active. This, however, was not the case during the Coipasa and Tauca wet periods. Lake-balance modelling of a landslide-dammed lake suggests a 10–15% increase in precipitation and a 3–4°C decrease in temperature at ∼30 ¹⁴C kyr BP as compared to the present. In addition, time-series analysis reveals a strong ENSO and TAV during that time. The landslide clusters in northwestern Argentina are therefore best explained by periods of more humid and more variable climates.