New Data on Chronology of Landscape-Paleoclimatic Stages in Northwestern Russia During the Late Glacial and Holocene

Lake Ladoga in northwestern Russia is Europe's largest lake. The postglacial historyof the Ladogabasin is for the first time documented continuously with high temporal resolution in the upper 13.3 m of a sediment core (Co1309) from the northwestern part of the lake. We applied a multiproxy approach including radiographic imaging, (bio-) geochemical and granulometric analyses. Age control was established combining radiocarbon dating with varve chronology, the latter anchored to a correlated radiocarbon age from a lake close by. The age-depth model reveals the onset of glacial varve sedimentation at 13 910AE140 cal. a BP, when Lake Ladoga was part of the Baltic Ice Lake. Linear extrapolation of published retreat rates of the Scandinavian Ice Sheet provides a formation age of the Luga moraine close to Lake Ladoga's southern shore of 14.5-15.9 cal. ka BP, older than previously assumed. Varve sedimentation covers the Bølling/Allerød interstadial, the Younger Dryas stadial and the Early Holocene. Varvethickness variations, conjoined with grain-size and geochemical variations, inform about the relative position of the Scandinavian Ice Sheet and the climate during the deglaciation phase. The upper limit of the varved succession marks the change from glaciolacustrine to normal lacustrine sedimentation and post-dates the drainage of the Baltic Ice Lake aswell as the formation of the Salpausselk€ a II moraine north of Lake Ladoga, by c. 250 years. The Holocene sediment record is divided into three periods in the following order: (i) a lower transition zone between the Holocene boundary and c. 9.5 cal. ka BP, characterized by mostly massive sediments with low organic content, (ii) a phase with increased organic content from c. 9.5 to 4.5 cal. ka BP corresponding to the Holocene Thermal Maximum, and (iii) a phase with relatively stable sedimentation in a lacustrine environment from c. 4.5 cal. ka BP until present.

Section: <114 Cal Ka Bp (Ice-free Holocene)mentioning

confidence: 99%

“…The data from these cores were complemented by investigation of the recent hydrological and limnological conditions in the lake, including lake-ice formation (e.g. Arslanov et al 2001;Davydova et al 2001). Holopainen et al 1996), and compared to studies of adjacent lakes, which have a similar or even connected history to Lake Ladoga (e.g.…”

mentioning

confidence: 99%

Deglaciation history of Lake Ladoga (northwestern Russia) based on varved sediments

Gromig

Wagner

Wennrich

et al. 2019

“…The dominance of Picea pollen in this interval was also observed in pollen records from the Karelian Isthmus (Arslanov et al 1999(Arslanov et al , 2001 and southern Karelia (Elina et al 2000;Miettinen et al 2002). ka BP; PZ 13.…”

Section: Discussion and Interpretationmentioning

confidence: 53%

“…ka BP; PZ 7. Earlier studies suggest that unstable conditions with abrupt environmental changes characterize the deglaciation period in the northwestern part of the Russian Plain (Arslanov et al 1999(Arslanov et al , 2001Subetto et al 2002aSubetto et al , 2003Wohlfarth et al 2002Wohlfarth et al , 2004. Most pollen-based reconstructions lack absolute dating (Malyasova & Spiridonova 1967;Malakhovskii et al 1969;Ladyshkina et al 1977;Elina et al 2000).…”

Section: Discussion and Interpretationmentioning

confidence: 99%

Vegetation and climate changes in northwestern Russia during the Lateglacial and Holocene inferred from the Lake Ladoga pollen record

Savelieva

Andreev

Gromig

et al. 2019

The new pollen record from the upper 12.75 m of a sediment core obtained in Lake Ladoga documents regional vegetation and climate changes in northwestern Russia over the last 13.9 cal. ka. The Lateglacial chronostratigraphy is based on varve chronology, while the Holocene stratigraphy is based on AMS 14 C and OSL dates, supported by comparison with regional pollen records. During the Lateglacial (c. 13.9-11.2 cal. ka BP), the Lake Ladoga region experienced several climatic fluctuations as reflected in vegetation changes. Shrub and grass communities dominated between c. 13.9 and 13.2 cal. ka BP. The increase in Picea pollen at c. 13.2 cal. ka BP probably reflects the appearance of spruce in the southern Ladoga region at the beginning of the Allerød interstadial. After c. 12.6 cal. ka BP, the Younger Dryas cooling caused a significant decrease in spruce and increase in Artemisia with other herbs, indicative of tundra-and steppe-like vegetation. A sharp transition from tundra-steppe habitats to sparse birch forests characterizes the onset of Holocene warming c. 11.2 cal. ka BP. Pine forests dominated in the region from c. 9.0 to 8.1 cal. ka BP. The most favourable climatic conditions for deciduous broad-leaved taxa existed between c. 8.1 and 5.5 cal. ka BP. Alder experiences an abrupt increase in the local vegetation c. 7.8 cal. ka BP. The decrease in tree pollen taxa (especially Picea) and the increase in herbs (mainly Poaceae) probably reflect human activity during the last 2.2 cal. ka. Pine forests have dominated the region since that time. Secale and other Cerealia pollen as well as ruderal herbs are permanently recorded since c. 0.8 cal. ka BP.

“…Despite the general warming since the Lateglacial, regional climate during the Early Holocene remained relatively cold and dry (Arslanov et al 2001;Heikkil€ a et al 2010;Shelekhova & Lavrova 2011;Subetto et al 2017). In general, lower than present temperatures (by 1-2°C in July and by 2-2.5°C in January) and lower annual precipitation (by 25-30 mm) in the region during the Early Holocene have been reconstructed (Arslanov et al 2001). ka BP (Subetto et al 2002).…”

Section: Temporal Changes In D 18 O Diatom Diatom Taxonomy and Lakementioning

confidence: 99%

Holocene hydrological variability of Lake Ladoga, northwest Russia, as inferred from diatom oxygen isotopes

Kostrova

Meyer

Bailey

et al. 2019

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 (d 18 O diatom ) 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 d 18 O diatom values range from +29.8 to +35.0&, and relatively higher d 18 O diatom 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 d 18 O diatom 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 d 18 O diatom values, whereas lower lake levels cause higher d 18 O diatom 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 d 18 O diatom values around +33.5& characterize a persistent evaporative lake system throughout the Holocene. As the Lake Ladoga d 18 O diatom record is roughly in line with the 60°N summer insolation, a linkage to broader-scale climate change is likely.