Lake-level variability in Salar de Coipasa, Bolivia during the past ∼40,000 yr

Abstract

Various paleoclimatic records have been used to reconstruct the hydrologic history of the Altiplano, relating this history to past variability of the South American summer monsoon. Prior studies of the southern Altiplano, the location of the world's largest salt flat, the Salar de Uyuni, and its neighbor, the Salar de Coipasa, generally agree in their reconstructions of the climate history of the past ∼ 24 ka. Some studies, however, have highly divergent climatic records and interpretations of earlier periods. In this study, lake-level variation was reconstructed from a ∼ 14-m-long sediment core from the Salar de Coipasa. These sediments span the last ∼ 40 ka. Lacustrine sediment accumulation was apparently continuous in the basin from ∼ 40 to 6 ka, with dry or very shallow conditions afterward. The fossil diatom stratigraphy and geochemical data (δ 13 C, δ 15 N, %Ca, C/N) indicate fluctuations in lake level from shallow to moderately deep, with the deepest conditions correlative with the Heinrich-1 and Younger Dryas events. The stratigraphy shows a continuous lake of variable depth and salinity during the last glacial maximum and latter stages of Marine Oxygen Isotope Stage 3 and is consistent with environmental inferences and the original chronology of a drill core from Salar de Uyuni.

Antarctic-like temperature variations in the Tropical Andes recorded by glaciers and lakes during the last deglaciation

“…a single P-T pair) associated with the glacial extent. We note that, despite major lake-size variations, both the continuous sediment accumulation in the Coipasa Basin throughout the study period (Nunnery et al, 2019) and the presence of shoreline records indicate that the lake did not completely dry prior to the Holocene; this algorithm is therefore applicable to the entire last deglaciation.…”

Morphological and molecular species boundaries in the Hyalella species flock of Lake Titicaca (Crustacea: Amphipoda)

“…Like many other ancient lakes, the Titicaca has a complex palaeo-environmental history (Cristescu et al, 2010). Thus, the different Altiplano basins conformed a single hydrological unit from the Early to Middle Pleistocene (Baker & Fritz, 2015;Nunnery et al, 2019), when water level experienced at least three major expansions (high stands) of up to 114, 104 and 54 m above present lake level (Fornari et al, 2001). Furthermore, the lake has passed through several periods of retraction coincident with global interglacial periods, when its level FIGURE 1 A, map of South America showing location of the Andean Altiplano; B, approximate area of the Altiplano showing placement of its main water bodies; C, sampling sites placed outside Lake Titicaca; D, sampling sites at Lake Titicaca itself.…”

“…60,000 yr BP (Fritz et al, 2004). In summary, the Altiplano lakes have a complex history of periodical basin connections, disconnections, episodes of desiccation, and abrupt changes in water salinity and depth, all of which may have exerted an important effect on the pattern of species diversification in the area (Nunnery et al, 2019;Fornari et al, 2001). Lake Titicaca harbours at least 533 species of aquatic organisms, of which only 12% are endemic to the lake (see Kroll et al, 2012, and references therein).…”

Phylogenomics of the Hyalella amphipod species-flock of the Andean Altiplano

“…Like many other ancient lakes such as the East African ones, the Altiplano lakes have experienced a complex palaeo-environmental history as the water level was subjected to at least three significant expansions from the Early to Middle Pleistocene. These shifts resulted in the joining of the different lake basins of the Altiplano into a single hydrological unit [8][9][10] . Besides, during global interglacial periods, the water level dropped considerably, resulting in an increase in water salinity, and a closed-basin configuration of the Titicaca 11 .…”