Diatom-based conductivity reconstruction and palaeoclimatic interpretation of a 40-ka record from Lake Zeribar, Iran

Sediment cores from Lake Zeribar in the Zagros Mountains of western Iran provide a record of changes in the diatom flora since about 40 ka. Conductivity transfer functions applied to diatom records from the lake indicate generally higher conductivity during the Last Glacial Maximum and Lateglacial, especially between 15.0 and 10.5 ka. This observation is consistent with previous interpretations of relatively arid conditions during this interval based on the Lake Zeribar pollen records. Oscillations between high- and low-conductivity states during this interval additionally suggest changes in precipitation associated with millennial-scale climate events, with relatively dry conditions during the Younger Dryas. Diatom-inferred conductivity is relatively low throughout the Holocene. Shifts in diatom composition occur in the Holocene record; however, minor variations in reconstructed conductivity are not considered significant.