A testimony of detachment of an inland lake from marine influence during the mid-Holocene in the Vestfold Hills region, East Antarctica

Abstract

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.

Geomorphological Insight of Some Ice Free Areas of Eastern Antarctica

“…Based on the variation of diatom population present in sediments suggest that the influence of seawater got weakened after ~5000 yrs. BP [37] and relative warmer climatic condition was prevalent [37,38]. Core studies from a lake in Grovnes Promontory by [39] have shown high productivity between ~8.3 to ~6 cal ka BP and that the ice free conditions prevailed around 4 cal ka BP.…”

Palaeoclimatic records from Antarctica and Southern Ocean: A review of Indian contributions

“…Presence/absence of diatom along with variation of sand percentage suggests the alternate glacial-interglacial phase prevailed in this region. Further, few studies have focussed on sediment records of the Vestfold Hills (Mazumder et al, 2013a;Mazumder et al, 2013b;Mazumder and Govil, 2013). Mazumder et al (2013a) suggested that the constant seawater influence in the lake (which was predominated in early Holocene) got weakened after 5000 yrs BP till date, based on diatom population and the abundance of salt crystal present in sediments.…”

“…Mazumder et al (2013a) suggested that the constant seawater influence in the lake (which was predominated in early Holocene) got weakened after 5000 yrs BP till date, based on diatom population and the abundance of salt crystal present in sediments. Mazumder et al (2013b), Mazumder and Govil (2013) reported the relatively warmer climatic condition in late Holocene based on the abundance of icier condition indicator species Fragilariopsis curta along with other diatom assemblages.…”