Correlation of data on loss-on-ignition and palynology for Late Quaternary climate change in southwestern Madhya Pradesh, India

摘要

Various proxy signals such as pollen, diatoms, isotopes, macrofossils, etc. are in vogue to reconstruct the palaeoclimate which plays a pivotal role in understanding the natural variability of the climatic system and to simulate the models to understand the trend of future climate changes relevant to society. However, not much attention has been paid to utilize chemical analysis of lacustrine sediments in reconstructing the palaeoclimate, except a few. The present study is designed to correlate palaeoclimatic and palaeovegetational changes on the basis of loss-on-ignition (LOI) data with those of the pollen data from Nitaya Lake in Nitaya village, Hoshangabad district, southwestern Madhya Pradesh, India. The Nitaya Lake is situated about 17 km southeast of Hoshangabad Township between 77°42'E long, and 22°40'N lat, in the close vicinity of Nitaya village in the Itarsi Forest Range (Figure 1). This ancient lake basin, measuring 300 m in length and 250 m at its widest, is sub-circular in outline. Topographically, this entire lake basin and the adjoining area is flat and is under agricultural practice by the local inhabitants. The average altitude of the lake and surrounding flat area is about 800 ft amsl. However, the hillocks, southwest of the lake are moderate-sized with the altitudes varying from 1800 to 2000 ft and support diversified tropical deciduous teak (Tectona gran-dis) forests. Geomorphologically, the catchment area is flat-topped, covered with black cotton soil, derived by weatheringfrom Deccan trap as the predominant soil type with patches of loam and sandy loam.