# Environmental evolution of a coastal lake in the Larsemann Hills, East Antarctica during the Holocene: a multi-proxy perspective

## TL;DR

The study tracks how a coastal lake in Antarctica changed from a marine to a freshwater system over thousands of years, revealing insights into past climate and sea level changes.

## Contribution

The study provides a high-resolution multi-proxy reconstruction of a coastal lake's environmental evolution in East Antarctica during the Holocene.

## Key findings

- Heart Lake was a submarine basin from 6.37 to 3.07 cal ka BP.
- Warmer conditions are indicated by increased chemical weathering indices around 4.3 cal ka BP.
- The lake transitioned to an isolated freshwater system by ~1.75 cal ka BP.

## Abstract

Coastal lakes in Antarctica provide exceptional archives of past climatic and environmental change. Their evolution is closely linked to variations in relative sea level (RSL) driven by deglaciation, making them ideal natural laboratories for investigating marine-lacustrine transitions and reconstructing ancient sea levels. This study presents a high-resolution reconstruction of mid- to late-Holocene paleoenvironmental changes from Heart Lake, a low-elevation coastal lake in the Larsemann Hills, East Antarctica. Multiple proxies, including diatom assemblages, environmental magnetic parameters, geochemical indicators, and sedimentological features, were employed to decipher the regional paleoclimate and environmental history. The lake existed as a submarine basin from approximately 6.37 to 3.07 cal ka BP. Around 4.3 cal ka BP, increasing chemical weathering indices suggest a trend toward warmer conditions in the lake. The first appearance of lacustrine diatoms around 3.07 cal ka BP marks the onset of environmental transition within the basin. By ~ 1.75 cal ka BP, the lake had become an isolated freshwater system. This shift from a marine to a lacustrine environment was likely driven by a post-glacial isostatic rebound and the consequent uplift of the land surface.

The online version contains supplementary material available at 10.1038/s41598-026-39218-8.