A multi-proxy study was carried out to address climate-culture
relationship from two trenches one each from Kaj and Kanjetar
(mid-Saurashtra coast) deposited in a lacustrine setting, since ~1960 Cal
BC and ~2230 Cal BC, respectively. The salinity of aqueous soil solution
(0.1 ppt) and fresh water thecamoebians in both the sites indicate fresh
water depositional environment. But, an increase in salinity (0.2 ppt) in
the top clayey sediment in Kanjetar is attributed to water evaporation
through upward capillary action from moisture deficit exposed land. The
fragments of ancient potteries and other artefacts recovered from the
bottom sediment provide evidences of Sorath-Harappan colonization in the
vicinity which was not an urban site. The abundant cyanobacterium remains,
low terrigenous organic matter, aquatic pollen and low thecamoebians in
bottom sediment indicates low precipitation and arid climatic conditions
~2000 BC. During this period the dominance of evergreen and moist deciduous
arboreals from both the sites do not show equilibrium with the prevailing
dry/arid climate and therefore, the pollen assemblage here represents the
remnants of wetter middle Holocene vegetation in the region. Phytoliths of
drought-tolerant summer season crops also reflects here changes made in the
agricultural strategy by Harappans in response to climate. The increase in
deciduous arboreal pollen since the last ~2000 years represents equilibrium
with the dry/arid climate. But, enhanced limnic conditions recorded with
the help of thecamoebians during this period is attributed to changes in
wetland configuration induced by hydrostatic changes in the river mouth
that was largely defined by the dynamics of sediment deposition through
rain-fed rivers/streams in the region.
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