Fig. 2

Mineralogical and geochemical composition of the six sediment samples from the Laguna Lejía terrace (10.3–11 kyr BP). a Mineralogical composition of the crystalline fraction measured by X-ray diffraction (XRD). The minerals with the blue color scale are feldspars. b Major and c minor elements in the soluble fraction of sediment samples. The sulfur concentration was calculated from sulfate, and the nitrogen concentration was calculated from nitrate since nitrite was below the quantification level (1.6 ppb). Error bars represent the standard deviation of triplicate measurements