Mid-late Holocene monsoonal variations from mainland Gujarat, India : A multi-proxy study for evaluating climate culture relationship

A multi-proxy study involving palynology, phytoliths, sedimentology, clay mineralogy, carbon isotopes and magnetic mineralogy was carried out on Wadhwana Lake sediments from sub-humid zone of mainland Gujarat to determine the mid-Holocene climatic fluctuations, and its possible impact on the Harappan culture. The 1.03 m sediment profile of Wadhwana Lake shows five paleoclimatic phases. The study reveals high lake stand during Phase I (~ 7500–5560 cal yr BP). A considerable cool and moist climatic condition during Phase I is inferred due to the presence of pollen belonging to wet evergreen taxa and high phytolith climatic index ‘Ic’. Later part of Phase I show gradual replacement of evergreen to deciduous pollen taxa, decrease in Ic value and dominance of smectite over kaolinite, indicating a reduction in wet climatic condition due to decline in the precipitation and prevalence of seasonally dry climate