Holocene paleoclimate reconstruction from the phytolith of the lake-fill sequence of Ganga Plain

Abstract

A 2.8 m thick Holocene sediment succession of Lahuradewa lake, located on the interfluve surface of Ghaghara–Ami rivers, close to the Lahuradewa archaeological site, is studied for phytolith assemblage to reconstruct the palaeoclimate variability during the Holocene. The phytolith morphotypes of grasses (Poaceae) have been used as proxy environmental indicators. Phytolith morphotypes belonging to subfamily Panicoidae indicate warm and humid climate; Chloridoidae indicate warm and dry climate and Festucoidae indicate cool and moist climate. Lake profile in general shows dominance of Panicoidae morphotypes over others, though at certain intervals they show fluctuating trend. Well-defined parameter of phytolith index (Iph) is used to infer dry phases in the succession. On the basis of Iph, five wet phases alternating with four dry phases have been identified during the past 10,600 cal yrs BP. The four dry phases are: (1) 10,300–9,200 cal yrs BP, (2) 5300–4100 cal yrs BP, (3) 1650–1200 cal yrs BP and (4) 950–700 cal yrs BP, out of which the 5300–4100 cal yrs BP dry phase was the most prominent.