Subglacial carbonate deposits as a potential proxy for glacier's existence

Abstract. The retreat of ice shelves and glaciers over the last century provides unequivocal evidence of recent global warming. Glacierets (miniature glaciers) are an important component that highlights the global retreat of glaciers, but knowledge of their behaviour prior to the Little Ice Age is lacking. Here, we present subglacial carbonate deposits from a recently exposed surface previously occupied by the disappearing Triglav Glacier (southeastern European Alps) that may elucidate the glacier’s existence throughout the entire Holocene since their maximum uranium-thorium (U-Th) ages suggest their possible preservation since the Last Glacial Maximum and Younger Dryas. These thin deposits, formed by regelation, are easily eroded if exposed during previous Holocene climatic optima. The age data indicate the glacier’s present unprecedented level of retreat since the Last Glacial Maximum, and the potential of subglacial carbonates as additional proxies to highlight the extraordinary nature of the current global climatic changes.