Holocene hydrological variability of Lake Ladoga, northwest Russia, as inferred from diatom oxygen isotopes. (27th February 2019)

• Record Type: Journal Article
• Authors: Kostrova, Svetlana S.; Meyer, Hanno; Bailey, Hannah L.; Ludikova, Anna V.; Gromig, Raphael; Kuhn, Gerhard; Shibaev, Yuri A.; Kozachek, Anna V.; Ekaykin, Alexey A.; Chapligin, Bernhard
• Other Names: Melles M. guestEditor.; Svendsen J. I. guestEditor.; Fedorov G. guestEditor.; Wagner B. guestEditor.
• Is Part Of: Boreas. Volume 48:Number 2(2019)
• Page Start: 361
• Page End: 376
• Publication Date: 2019-02-27
• Subjects: Geology, Stratigraphic -- Quaternary -- Periodicals; 551.79
• DOI: 10.1111/bor.12385
• Languages: English
• ISSNs: 0300-9483

Abstract

Abstract : This article presents a new comprehensive assessment of the Holocene hydrological variability of Lake Ladoga, northwest Russia. The reconstruction is based on oxygen isotopes of lacustrine diatom silica (δ 18 Odiatom ) preserved in sediment core Co 1309, and is complemented by a diatom assemblage analysis and a survey of modern isotope hydrology. The data indicate that Lake Ladoga has existed as a freshwater reservoir since at least 10.8 cal. ka BP. The δ 18 Odiatom values range from +29.8 to +35.0‰, and relatively higher δ 18 Odiatom values around +34.7‰ between c . 7.1 and 5.7 cal. ka BP are considered to reflect the Holocene Thermal Maximum. A continuous depletion in δ 18 Odiatom since c . 6.1 cal. ka BP accelerates after c . 4 cal. ka BP, indicating Middle to Late Holocene cooling that culminates during the interval 0.8–0.2 cal. ka BP, corresponding to the Little Ice Age. Lake‐level rises result in lower δ 18 Odiatom values, whereas lower lake levels cause higher δ 18 Odiatom values. The diatom isotope record gives an indication for a rather early opening of the Neva River outflow at c . 4.4–4.0 cal. ka BP. Generally, overall high δ 18 Odiatom values around +33.5‰ characterize a persistent evaporative lake system throughout the Holocene. As the Lake Ladoga δ 18 Odiatom record is roughly in line with the 60°N summer insolation, a linkage to broader‐scale climate change is likely.