Papers by Elena Bezrukova
Polar Record
The DIMA Network (Developing Innovative Multi-proxy Analyses – in Siberia and the Russian Far Eas... more The DIMA Network (Developing Innovative Multi-proxy Analyses – in Siberia and the Russian Far East (SRFE)) started from a small nucleus of palaeoenvironmental researchers in the UK and SRFE at a workshop in 2008 and currently includes researchers from over 25 institutions. The mutual interest in creating long-term records of environmental change was rekindled during workshops in Magadan (2018), Tomsk (2018) and Southampton (2019). These events were organised to connect researchers from the UK and SRFE with these aims: (1) provide training in new techniques and methods, (2) facilitate knowledge transfer about local sites and conditions, (3) stimulate large-scale collaborative projects across SRFE and (4) inspire a new generation of palaeoenvironmental researchers.
Quaternary Research, 2020
Recent revision of the Pleistocene glaciation boundaries in northern Eurasia has encouraged the s... more Recent revision of the Pleistocene glaciation boundaries in northern Eurasia has encouraged the search for nonglacial geological records of the environmental history of northern West Siberia. We studied an alluvial paleosol-sedimentary sequence of the high terrace of the Vakh River (middle Ob basin) to extract the indicators of environmental change since Marine Oxygen Isotope Stage (MIS) 6. Two levels of the buried paleosols are attributed to MIS 5 and MIS 3, as evidenced by U/Th and radiocarbon dates. Palynological and pedogenetic characteristics of the lower pedocomplex recorded the climate fluctuations during MIS 5, from thePicea-Larixtaiga environment during MIS 5e to the establishment of the tundra-steppe environment due to the cooling of MIS 5d or MIS 5b and partial recovery of boreal forests withPiceaandPinusin MIS 5c or MIS 5a. The upper paleosol level shows signs of cryogenic hydromorphic pedogenesis corresponding to the tundra landscape, with permafrost during MIS 3. Bould...
Geography and Natural Resources, 2008
Presented are the cartographic models for the present-day and potential vegetation in the key are... more Presented are the cartographic models for the present-day and potential vegetation in the key area of Baikalian Siberia which provide a basis for prognostic analysis and synthesis. It is shown that geobotanical forecasting should be treated as a single complicated cartographic process having its logic and structure. Evolutionary-dynamical approach is the most effective tool for solving geobotanical forecasting problems.
Lake Baikal, 2000
... and the Holocene were taken from eight bogs and two outcrops of peat sediment on the southeas... more ... and the Holocene were taken from eight bogs and two outcrops of peat sediment on the southeastern and eastern coasts of Lake Baikal and examined for fossil pollen, plant macrofossils, and charcoal fragments. The chronology of each deposit is based on radiocarbon dating. ...
Quaternary Science Reviews, 2017
occurrences, plus a record of dated plant macrofossils, indicate that some tree populations exist... more occurrences, plus a record of dated plant macrofossils, indicate that some tree populations existed in southern and Eastern Europe and central and far-eastern Eurasia. PFT composition of the herbaceous biomes emphasises the significant contribution of diverse forbs to treeless vegetation, a feature often obscured in pollen records. An increase in moisture ca. 14 kyr cal BP is suggested by a shift to woody biomes and an increase in sites recording initialization and development of lakes and peat deposits, particularly in the European portion of the region. Deforestation of Western Europe, presumably related to agricultural expansion, is clearly visible in the most recent two millennia.
Radiocarbon, 2004
New radiocarbon dates obtained from Late Pleistocene and Holocene deposits of the southern, easte... more New radiocarbon dates obtained from Late Pleistocene and Holocene deposits of the southern, eastern, and northern shores of Lake Baikal in 1995–2001 are presented, and the most important results of paleoenvironmental studies based on C data are discussed. The following paleogeographic events were verified with the help of C dating: 1) first Late Pleistocene glaciation (Early Zyryan); 2) Middle Zyryan interstadial; 3) loess formation during the Late Zyryan (Sartan) deglaciation; 4) warm and cold events in the Late Glacial; and 5) vegetation changes and forest successions during the Late Glacial and Holocene.
Supplement to: Tarasov, Pavel E; Bezrukova, Elena V; Krivonogov, Sergey K (2009): Late Glacial and Holocene changes in vegetation cover and climate in southern Siberia derived from a 15 kyr long pollen record from Lake Kotokel. Climate of the Past, 5, 285-295, doi:10.5194/cp-5-285-2009, Jun 11, 2009
In this study a radiocarbon-dated pollen record from Lake Kotokel (52°47' N, 108°07' E, 4... more In this study a radiocarbon-dated pollen record from Lake Kotokel (52°47' N, 108°07' E, 458 m a.s.l.) located in southern Siberia east of Lake Baikal was used to derive quantitative characteristics of regional vegetation and climate from about 15 kyr BP (1 kyr = 1000 cal. yr) until today. Quantitative reconstruction of the late glacial vegetation and climate dynamics suggests that open steppe and tundra communities predominated in the study area prior to ca. 13.5 kyr BP and again during the Younger Dryas interval, between 12.8 and 11.6 kyr BP. The pollen-based climate reconstruction suggests lower-than-present mean January (~ -38 °C) and July (~ 12 °C) temperatures and annual precipitation (~ 270-300 mm) values during these time intervals. Boreal woodland replaced the primarily open landscape around Kotokel three times at about 14.8-14.7 kyr BP, during the Allerød Interstadial between 13.3-12.8 kyr BP and with the onset of the Holocene interglacial between 11.5 and 10.5 kyr BP, presumably in response to a noticeable increase in precipitation, and in July and January temperatures. The maximal spread of the boreal forest (taiga) communities in the region is associated with a warmer and wetter-than-present climate (Tw ~ 17-18 °C, Tc ~ -19 °C, Pann ~ 500-550 mm) that occurred ca. 10.8-7.3 kyr BP. During this time interval woody vegetation covered more than 50 % of the area within a 21x21 km window around the lake. The pollen-based best modern analogue reconstruction suggests a decrease in woody cover percentages and in all climatic variables about 7-6.5 kyr BP. Our results demonstrate a gradual decrease in precipitation and mean January temperature towards their present-day values in the region around Lake Kotokel since that time.
Lake Baikal, 2000
ABSTRACT This chapter describes the paleoclimatic record over the period of 5 million years based... more ABSTRACT This chapter describes the paleoclimatic record over the period of 5 million years based on variations in diatom abundance in the sediments of a 200 m core obtained from Lake Baikal. The data represent a long, continuous continental record of climate changes in Central Asia during the Late Cenozoic. The record shows the climatic cooling trend that started in Pleistocene and is superimposed on the short-term cyclic climatic variations controlled by the Earth's orbital parameters. The record also reveals the presence of the two cold episodes (each about 300 Ka long) at the time intervals 2.82–2.48 Ma and 1.75–1.45 Ma characterized by glaciations at their maximum phases. These cooling periods in Lake Baikal record are also registered as global cooling in other paleoclimate records of the Northern Hemisphere. The continental record of Lake Baikal contains the majority of climatic events found in marine records and demonstrates that continental regions of Asia responded to all major changes in the Earth's climate recorded in the long oxygen isotopic records.
On the basis of new factual material, the history of the formation of the Prebaikalia vegetation ... more On the basis of new factual material, the history of the formation of the Prebaikalia vegetation cover is considered. For this purpose data of palynological analysis for nine sections of lacustrine-palustrine deposits were used jointly with the results of carpological analysis and radiocarbon dating. There are five basic periods in development of Prebaikalian vegetation for the last 12 thousand years. It is shown that the climatic setting was not uniform during this period.
Russian Geology and Geophysics
The paper describes data of analysis of the uppermost (8 to 14 m) layer of bottom sediments of La... more The paper describes data of analysis of the uppermost (8 to 14 m) layer of bottom sediments of Lake Baikal sampled by tube corers on the top of the underwater Akademichesky Ridge at three sites separated by large distances (30 km). The cores were subjected to primary lithological description, photography on color film and X-ray fluorography. Samples taken at 10 cm intervals were analyzed for the content of water, opal silica, organic carbon, total uranium, molybdenum, and 14 other elements. Quantitative diatom analysis was done at frequency of 2-10 cm using light microscopy. Scanning electron microscopy was applied to ensure correct identification of some diatom species. Pollen grains and sponge spicules were also identified and counted. A section of one of the cores was subjected to paleomagnetic measurements and a magnetic excursion was found. The three cores perfectly correlate with each other exhibiting cyclic changes of the content of opal silica and diatom frustules. A new met...
Geography and Natural Resources, 2009
Abstract We examine the sequence of changes in the structure of the geosystems of the Primorsky R... more Abstract We examine the sequence of changes in the structure of the geosystems of the Primorsky Range (Baikal region) for the last 6000 years, based on a continuous recording of fluctuations of the vegetation reconstructed from spore-pollen complexes of a high peat bog. We determined the chronological timeframe of paleogeographical events. The study showed that there occurred a radical structure transformation of the geosystems in the mid-late Holocene, along with a recurrence of similar landscape transformations caused by the instability of natural conditions.
Archaeology, Ethnology and Anthropology of Eurasia, 2013
Peer reviewedPostprin
Long Continental Records from Lake Baikal, 2003
... The results of a palynological study of the cores with 14 radio-carbon dates revealed the fol... more ... The results of a palynological study of the cores with 14 radio-carbon dates revealed the following vegetation history since the late glacial. ... Pollen Record from the Eastern Shore of Lake Baikal 211 FIG ... Solid circles, radiocarbon ages; open circles, calibrated ages (calendar years ...
Long Continental Records from Lake Baikal, 2003
... The records of Holocene regressions can be recognized only in the near-shore sediments ofLake... more ... The records of Holocene regressions can be recognized only in the near-shore sediments ofLake Hovsgol. ... It should be noted that in the late glacial and Holocene, it coincides with the water-level fluctua-tions of the lakes in northwestern Mongolia (Walter and Batnasan ...
Quaternary International, 2014
This paper presents a new decadal-resolution fossil pollen record from Lake Kotokel (52 47 0 N, 1... more This paper presents a new decadal-resolution fossil pollen record from Lake Kotokel (52 47 0 N, 108 07 0 E, 458 m a.s.l.) and provides a reconstruction of the Last Glacial Maximum (LGM) vegetation and environments in the study area during this interval of globally harsh climate. Lake Kotokel is situated close to the eastern shoreline of Lake Baikal, in the boreal forest zone of southern Siberia. The analysed 190 cm long section 6 of the bottom core KTK10 (KTK10/6) consists of compact, undisturbed, greenish-grey to dark-grey, slightly laminated silty clay indicating continuous lacustrine sedimentation throughout the LGM period ca. 26.8e19.1 cal. ka BP. The age model is supported by 11 calibrated AMS dates. The results of pollen analysis and pollen-based biome reconstruction show that steppe and tundra vegetation composed of grasses and various herbs dominated ca. 26.8e19.1 cal. ka BP. Occurrence of conifer tracheids and stomata throughout the record, together with small quantities of boreal conifer and broadleaf tree and shrub taxa pollen, suggests the presence of single trees or small forest stands in the lake vicinity, most likely in the river valleys. Application of the biomisation method and the resulting numerical scores of the most characteristic biomes (steppe, tundra and cold deciduous forest) show minor fluctuations, signifying stability of the regional vegetation cover during the analysed LGM interval. In contrast to the regional biomes, the local environmental indicators demonstrate greater sensitivity of the lake system to decadal-and century-scale climate variability. The highest pollen percentages of Ranunculaceae, representing littoral/meadow vegetation communities, are registered ca. 23.8e23.4 cal. ka BP. This and an increase in coarse-grained sand particles together with slightly increased total inorganic carbon (TIC) values representing calcite in the KTK10/6 sediment provide evidence of a much shorter than present distance between the coring site and the shoreline and a reduced lake area, in line with a drier-than-present LGM climate. A general stability of the grassland vegetation in the study region ca. 26.8e19.1 cal. ka BP and relatively constant total organic carbon (TOC) values support the hypothesis that this productive vegetation could stably serve as a perennial food resource for large populations of herbivores, thus providing favourable environments for the local hunteregatherers inhabiting the Lake Baikal region during the LGM interval.
Quaternary International, 1997
The Baikal Drilling Project (BDP) is a multinational effort to investigate the paleoclimatic hist... more The Baikal Drilling Project (BDP) is a multinational effort to investigate the paleoclimatic history and tectonic evolution of the Baikal sedimentary basin during the Late Neogene. In March 1993 the Baikal drilling system was successfuly deployed from a barge frozen into position over a topographic high, termed the Buguldeika saddle, in the southern basin of Lake Baikal. The BDP-93 scientific team, made up of Russian, American and Japanese scientists, successfully recovered the first long (>100 m) hydraulic piston cores from two holes in 354 m of water. High quality cores of 98 m (Hole 1) and 102 m (Hole 2), representing sedimentation over the last 500,000 years, were collected in 78 mm diameter plastic liners with an average recovery of 72% and 90%, respectively. Magnetic susceptibility logging reveals an excellent hole-to-hole correlation. In this report the scientific team describes the preliminary analytical results from BDP-93 hole 1 cores. Radiocarbon dating by accelerator mass spectrometry provides an accurate chronology for the upper portion of Hole 1. Detailed lithologic characteristics, rock magnetic properties and inorganic element distributions show a significant change to the depositional environment occuring at 50 m subbottom depth, approximately 250,000 BP. This change may be due to uplift and rotation of the horst block in the Buguldeika saddle. The sedimentary section above 50 m is pelitic with varve-like laminae, whereas the section below 50 m contains a high proportion of sand and gravel horizons often organized into turbidite sequences. Accordingly, high resolution seismic records reveal a change in sonic velocity at this depth. It is inferred that sedimentation prior to 250 ka BP was from the west via the Buguldeika river system. After 250 ka BP the Bugnldeika saddle reflects an increase in hemipelagic sediments admixed with free-grained material from the Selenga River drainage basin, east of Lake Baikal. Variations in the spore-pollen assemblage, diatoms, biogenic silica content, rock magnetic properties, clay mineralogy and organic carbon in the upper 50 m of BDP-93-1 reveal a detailed record of climate change over approximately the last 250,000 years. These variables alternate in a pattern characteristic of glacial/interglacial climatic fluctuations. The present age model suggests that the climate signal recorded in Lake Baikal sediments is similar to Late Quaternary signals recorded in Chinese loess sections and in marine sediments.
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Papers by Elena Bezrukova