sup 210^Pb dating and trace metal accumulation study of sediment cores from Navegaon Bandh and Bodhalkasa Lakes, Gondia District, Maharashtra, India

The sediment cores of the Bodhalkasa and the Navegaon Bandh Lakes encompass the historical accumulation of metal concentrations covering approximately 138 and 226 years, respectively, by assuming the constant accumulation rate down the cores. The average rate of sedimentation in the Bodhalkasa Lake was found to be 0.6797 cm/year and that of the Navegaon Bandh Lake was 0.9307 cm/year. The core sediments of the Bodhalkasa Lake show enrichment of Pb (1.03 times) in contrast with no enrichments in the Navegaon Bandh Lake. The elements like Cr, V, Sc, Co, Ni, Cu and Zn show the highest enrichment factor in the core sediments of the Navegaon Bandh and may also be attributed to the soils derived from the Pre-Sakoli group rocks and mafic, ultramafic rocks of the Sakoli Groups. The Cr enrichment in the Navegaon Bandh Lake may be attributed to Chromite pods within the Pre-Sakoli Rocks. The rare earth elements (REEs) are enriched 0.88-1.74 and 0.88-1.26 times crustal abundance, respectively, for the Bodhalkasa Lake and the Navegaon Bandh Lake. The enrichment factors of REEs in the Bodhalkasa Lake are higher than those in the Navegaon Bandh Lake. The enrichment of REEs in the watersheds of these lakes may be due to the increased input from soils and weathered rocks. The comparison of correlation coefficient of elements in the Bodhalkasa and the Navegaon Bandh Lakes with the polluted lakes of the Vidharbha region revealed the higher level of pollution of Cu, Cr and Ni in the Navegaon Bandh Lake as compared to the Bodhalkasa Lake.