A Testimony of Detachment of an Inland Lake from Marine Influence during the Mid-Holocene in the Vestfold Hills Region, East Antarctica

A 47 cm long sediment core collected from an inland lake of the Vestfold Hills, East Antarctica has been examined to reconstruct the palaeolacustrine environmental changes. The core shows dates at two core intervals of 18–19 cm and 28–29 cm as 5050 ± 98 yrs BP and 5560 ± 96 yrs BP, respectively. The core exhibits a good amount of diatom population throughout the length. Prior to 5560 ± 96 yrs BP, the core shows high abundance of diatom population (>10 × 10⁷ g⁻¹) along with sufficient salt crystal, which indicates the connection of this lake with the marine environment. From 5560 ± 96 yrs BP to 5050 ± 98 yrs BP the total number diatoms decreased substantially along with the decrease in salt crystal, which indicates the withdrawal of the marine influence from the lake during that period. From 5050 ± 98 yrs BP to Recent, the low number of diatoms and the rare occurrence of salt crystal suggest that the lake remained mostly detached from the sea during the last 5000 yrs.