Pliocene to Pleistocene climate and environmental history of Lake El'gygytgyn, Far East Russian Arctic, based on high-resolution inorganic geochemistry data

Abstract. The 3.6 Ma sediment record of Lake El'gygytgyn, Far East Russian Arctic, represents the longest continuous climate archive of the terrestrial Arctic. Its elemental composition monitored by X-ray fluorescence scanning exhibits significant changes since the Mid-Pliocene caused by climate driven variations in the primary production, postsedimentary diagenetic processes, and current activity in the lake as well as weathering processes in its catchment. During the Mid to Late Pliocene, warmer and wetter climatic conditions are reflected by elevated Si / Ti ratios, indicating enhanced diatom production in the lake. Prior to 3.3 Ma, this signal is highly masked by intensified detrital input from the catchment, visible in maxima of clastic-related proxies such as the K concentration. In addition, calcite formation in the early lake history points to enhanced nutrient flux into the lake caused by intensified weathering in its catchment. Its termination at ca. 3.3 Ma is supposed to be linked to the development of permafrost in the region triggered by a first cooling in the Mid-Pliocene. After ca. 3.0 Ma the elemental data suggest a gradual transition to Quaternary-style glacial / interglacial cyclicity. In the early Pleistocene, the cyclicity was first dominated by variations on the 41 ka obliquity band but experienced a change to a 100 ka eccentricity dominance after the Middle Pleistocene Transition at ca. 1.2 to 0.7 Ma. This clearly demonstrates the sensitivity of the Lake El'gygytgyn record to orbital forcing. A successive decrease of the baseline-levels of the redox-sensitive Mn / Fe ratio and magnetic susceptibility between 2.3 to 1.8 Ma reflects an overall change in the bottom water oxygenation due to an intensified occurrence of pervasive glacial episodes in the early Quaternary. The coincidence with major changes in the North Pacific and Bering Sea paleoceanography at ca. 1.8 Ma implies that the change in lake hydrology was caused by regional cooling and/or changes in the ocean-land moisture transport. Further rising TOC and TN values after ca. 1.6 Ma are attributed to a progressive intensification of the glacial intensity. In the course of the Quaternary glacial/interglacial sequence eight so-called "super-interglacials" occur. Their exceptional warm conditions are reflected by extreme Si / Ti peaks accompanied by lows in Ti, K, and Fe, thus indicating an extraordinary high lake productivity.

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Pliocene to Pleistocene climate and environmental history of Lake El'gygytgyn, Far East Russian Arctic, based on high-resolution inorganic geochemistry data

Climate of the Past ◽

10.5194/cp-10-1381-2014 ◽

2014 ◽

Vol 10 (4) ◽

pp. 1381-1399 ◽

Cited By ~ 24

Author(s):

V. Wennrich ◽

P. S. Minyuk ◽

V. Borkhodoev ◽

A. Francke ◽

B. Ritter ◽

...

Keyword(s):

North Pacific ◽

Far East ◽

Early Pleistocene ◽

Middle Pleistocene ◽

Gradual Transition ◽

Russian Arctic ◽

Lake Productivity ◽

The North ◽

Lake El’Gygytgyn ◽

The North Pacific

Abstract. The 3.6 Ma sediment record of Lake El'gygytgyn/NE Russia, Far East Russian Arctic, represents the longest continuous climate archive of the terrestrial Arctic. Its elemental composition as determined by X-ray fluorescence scanning exhibits significant changes since the mid-Pliocene caused by climate-driven variations in primary production, postdepositional diagenetic processes, and lake circulation as well as weathering processes in its catchment. During the mid- to late Pliocene, warmer and wetter climatic conditions are reflected by elevated Si / Ti ratios, indicating enhanced diatom production in the lake. Prior to 3.3 Ma, this signal is overprinted by intensified detrital input from the catchment, visible in maxima of clastic-related proxies, such as K. In addition, calcite formation in the early lake history points to enhanced Ca flux into the lake caused by intensified weathering in the catchment. A lack of calcite deposition after ca. 3.3 Ma is linked to the development of permafrost in the region triggered by cooling in the mid-Pliocene. After ca. 3.0 Ma the elemental data suggest a gradual transition to Pleistocene-style glacial–interglacial cyclicity. In the early Pleistocene, the cyclicity was first dominated by variations on the 41 kyr obliquity band but experienced a change to a 100 kyr eccentricity dominance during the middle Pleistocene transition (MPT) at ca. 1.2–0.6 Ma. This clearly demonstrates the sensitivity of the Lake El'gygytgyn record to orbital forcing. A successive decrease of the baseline levels of the redox-sensitive Mn / Fe ratio and magnetic susceptibility between 2.3 and 1.8 Ma reflects an overall change in the bottom-water oxygenation due to an intensified occurrence of pervasive glacial episodes in the early Pleistocene. The coincidence with major changes in the North Pacific and Bering Sea paleoceanography at ca. 1.8 Ma implies that the change in lake hydrology was caused by a regional cooling in the North Pacific and the western Beringian landmass and/or changes in the continentality. Further increases in total organic carbon and total nitrogen content after ca. 1.6 Ma are attributed to reduced organic matter decay in the sediment during prolonged anoxic periods. This points to more extensive periods of perennial ice coverage, and thus, to a progressive shifts towards more intense peak glacial periods. In the course of the Pleistocene glacial–interglacial sequence eight so-called "super-interglacials" occur. Their exceptionally warm conditions are reflected by extreme Si / Ti peaks accompanied by lows in Ti, K, and Fe, thus indicating extraordinary high lake productivity.

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Late Pliocene and early Pleistocene environments of the north-eastern Russian Arctic inferred from the Lake El'gygytgyn pollen record

Climate of the Past Discussions ◽

10.5194/cpd-9-4599-2013 ◽

2013 ◽

Vol 9 (4) ◽

pp. 4599-4653 ◽

Cited By ~ 11

Author(s):

A. A. Andreev ◽

P. E. Tarasov ◽

V. Wennrich ◽

E. Raschke ◽

U. Herzschuh ◽

...

Keyword(s):

Environmental Changes ◽

Lacustrine Sediments ◽

Early Pleistocene ◽

Pollen Record ◽

Russian Arctic ◽

Coprophilous Fungi ◽

Climate Conditions ◽

Late Pliocene ◽

The North ◽

Lake El’Gygytgyn

Abstract. The 318 m thick lacustrine sediment record in Lake El'gygytgyn, northeastern Russian Arctic cored by the international El'gygytgyn Drilling Project provides unique opportunities allowing the time-continuous reconstruction of the regional paleoenvironmental history for the past 3.6 Myr. Pollen studies of the lower 216 m of the lacustrine sediments show their value as an excellent archive of vegetation and climate changes during the Late Pliocene and Early Pleistocene. About 3.50–3.35 Myr BP the vegetation at Lake El'gygytgyn, in nowadays tundra area, was dominated by spruce-larch-fir-hemlock forests. After ca. 3.4 Myr BP dark coniferous taxa gradually disappeared. A very pronounced environmental changes took place at ca. 3.305–3.275 Myr BP, corresponding with the Marine Isotope Stage (MIS) M2, when treeless tundra- and steppe-like habitats became dominant in the regional vegetation. Climate conditions were similar to those of Late Pleistocene cold intervals. Numerous coprophilous fungi spores identified in the pollen samples suggest the presence of grazing animals around the lake. Following the MIS M2 event, larch-pine forests with some spruce mostly dominated in the area until ca. 2.6 Myr BP, interrupted by colder and drier intervals ca. 3.04–3.02, 2.93–2.91, and 2.725–2.695 Myr BP. At the beginning of the Pleistocene, ca. 2.6 Myr BP, noticeable climatic deterioration occurred. Forested habitats changed to predominantly treeless and shrubby environments, which reflect a relatively cold and dry climate. Revealed peaks in green algae colonies (Botryococcus) around 2.53, 2.45, 2.320–2.305 and 2.175–2.150 Myr BP suggest a spread of shallow water environments. Few intervals (i.e. 2.55–2.53, ca. 2.37, and 2.35–2.32 Myr BP) with a higher presence of coniferous taxa (mostly pine and larch) document some relatively short-term climate ameliorations.

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Biogeochemical variability during the past 3.6 million years recorded by FTIR spectroscopy in the sediment record of Lake El'gygytgyn, Far East Russian Arctic

Climate of the Past ◽

10.5194/cp-10-209-2014 ◽

2014 ◽

Vol 10 (1) ◽

pp. 209-220 ◽

Cited By ~ 10

Author(s):

C. Meyer-Jacob ◽

H. Vogel ◽

A. C. Gebhardt ◽

V. Wennrich ◽

M. Melles ◽

...

Keyword(s):

Far East ◽

Climatic Conditions ◽

Russian Arctic ◽

Accumulation Rates ◽

Sediment Record ◽

High Accumulation ◽

Late Pliocene ◽

The Past ◽

Lake El’Gygytgyn ◽

Middle Pliocene

Abstract. A number of studies have shown that Fourier transform infrared spectroscopy (FTIRS) can be applied to quantitatively assess lacustrine sediment constituents. In this study, we developed calibration models based on FTIRS for the quantitative determination of biogenic silica (BSi; n = 420; gradient: 0.9–56.5%), total organic carbon (TOC; n = 309; gradient: 0–2.9%), and total inorganic carbon (TIC; n= 152; gradient: 0–0.4%) in a 318 m-long sediment record with a basal age of 3.6 million years from Lake El'gygytgyn, Far East Russian Arctic. The developed partial least squares (PLS) regression models yield high cross-validated (CV) R2CV = 0.86–0.91 and low root mean square error of cross-validation (RMSECV) (3.1–7.0% of the gradient for the different properties). By applying these models to 6771 samples from the entire sediment record, we obtained detailed insight into bioproductivity variations in Lake El'gygytgyn throughout the middle to late Pliocene and Quaternary. High accumulation rates of BSi indicate a productivity maximum during the middle Pliocene (3.6–3.3 Ma), followed by gradually decreasing rates during the late Pliocene and Quaternary. The average BSi accumulation during the middle Pliocene was ~3 times higher than maximum accumulation rates during the past 1.5 million years. The indicated progressive deterioration of environmental and climatic conditions in the Siberian Arctic starting at ca. 3.3 Ma is consistent with the first occurrence of glacial periods and the finally complete establishment of glacial–interglacial cycles during the Quaternary.

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Testing the potential of OSL, TT-OSL, IRSL and post-IR IRSL luminescence dating on a Middle Pleistocene sediment record of Lake El'gygytgyn, Russia

Climate of the Past Discussions ◽

10.5194/cpd-8-4779-2012 ◽

2012 ◽

Vol 8 (5) ◽

pp. 4779-4815

Author(s):

A. Zander ◽

A. Hilgers

Keyword(s):

Sediment Cores ◽

Far East ◽

Luminescence Dating ◽

The Arctic ◽

Middle Pleistocene ◽

The North ◽

Lake El’Gygytgyn ◽

Infra Red ◽

Major Factors ◽

Pleistocene Sediment

Abstract. Lake El'gygytgyn is a 12 km wide crater lake located in remote Chukotka in the far East Russian Arctic about 100 km to the north of the Arctic Circle. It was formed by a meteorite impact about 3.58 Ma ago. This study tests the paleomagnetic and proxy data-based Mid- to Late-Pleistocene sediment deposition history using novel luminescence dating techniques of sediment cores taken from the centre of the 175 m deep lake. For dating polymineral and quartz fine grains (4–11 μm grain size range) were extracted from nine different levels from the upper 28 m of sediment cores 5011-1A and 5011-1B. Polymineral sub-samples were analysed by infra-red stimulated luminescence (IRSL) and post-IR infra-red stimulated luminescence (post-IR IRSL) using single aliquot regenerative dose (SAR) sequences. SAR protocols were further applied to measure the blue light optically stimulated luminescence (OSL) and thermally-transferred OSL (TT-OSL) of fine-grained quartz supplemented by a multiple aliquot TT-OSL approach. According to an independent age model, the lowest sample from 27.8–27.9 m below lake bottom level correlates to the Brunhes-Matuyama (B/M) reversal. Finally, the SAR post-IR-IRSL protocol applied to polymineral fine grains was the only luminescence technique able to provide dating results of acceptable accuracy up to ca. 700 ka. Major factors limiting precision and accuracy of the luminescence chronology are, for some samples, natural signals already approaching saturation level, and overall the uncertainty related to the sediment water content and its variations over geological times.

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Chronology of Lake El'gygytgyn sediments – a combined magnetostratigraphic, palaeoclimatic and orbital tuning study based on multi-parameter analyses

Climate of the Past ◽

10.5194/cp-9-2413-2013 ◽

2013 ◽

Vol 9 (6) ◽

pp. 2413-2432 ◽

Cited By ~ 44

Author(s):

N. R. Nowaczyk ◽

E. M. Haltia ◽

D. Ulbricht ◽

V. Wennrich ◽

M. A. Sauerbrey ◽

...

Keyword(s):

Global Climate ◽

Far East ◽

Climatic Conditions ◽

Sedimentation Rates ◽

Scientific Drilling ◽

Lake El’Gygytgyn ◽

Age Model ◽

Orbital Tuning ◽

Lake Floor ◽

The Impact

Abstract. A 318-metre-long sedimentary profile drilled by the International Continental Scientific Drilling Program (ICDP) at Site 5011-1 in Lake El'gygytgyn, Far East Russian Arctic, has been analysed for its sedimentologic response to global climate modes by chronostratigraphic methods. The 12 km wide lake is sited off-centre in an 18 km large crater that was created by the impact of a meteorite 3.58 Ma ago. Since then sediments have been continuously deposited. For establishing their chronology, major reversals of the earth's magnetic field provided initial tie points for the age model, confirming that the impact occurred in the earliest geomagnetic Gauss chron. Various stratigraphic parameters, reflecting redox conditions at the lake floor and climatic conditions in the catchment were tuned synchronously to Northern Hemisphere insolation variations and the marine oxygen isotope stack, respectively. Thus, a robust age model comprising more than 600 tie points could be defined. It could be shown that deposition of sediments in Lake El'gygytgyn occurred in concert with global climatic cycles. The upper ~160 m of sediments represent the past 3.3 Ma, equivalent to sedimentation rates of 4 to 5 cm ka−1, whereas the lower 160 m represent just the first 0.3 Ma after the impact, equivalent to sedimentation rates in the order of 45 cm ka−1. This study also provides orbitally tuned ages for a total of 8 tephras deposited in Lake El'gygytgyn.

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Aeolian influx and related environmental conditions on Gran Canaria during the early Pleistocene

Quaternary Research ◽

10.1017/qua.2018.64 ◽

2018 ◽

Vol 91 (1) ◽

pp. 35-50 ◽

Cited By ~ 3

Author(s):

Inmaculada Menéndez ◽

José Mangas ◽

Esperança Tauler ◽

Vidal Barrón ◽

José Torrent ◽

...

Keyword(s):

Late Quaternary ◽

Textural Analysis ◽

Climatic Conditions ◽

Saharan Dust ◽

Early Pleistocene ◽

Middle Pleistocene ◽

Quartz Content ◽

Gran Canaria ◽

Climatic Oscillations ◽

Climatic Variations

AbstractThe island of Gran Canaria is regularly affected by dust falls due to its proximity to the Saharan desert. Climatic oscillations may affect the Saharan dust input to the island. Geochemical, mineralogical, and textural analysis was performed on a well-developed and representative early Pleistocene paleosol to examine Saharan dust contribution to Gran Canaria. Significant and variable Saharan dust content was identified in addition to weathering products such as iron oxides and clay minerals. Variations in quartz and iron oxide concentrations in the paleosol likely reflect different Saharan dust input in more/less-contrasted rhexistasic/biostatic climatic conditions. Linking the quartz content in Canarian soils, the Ingenio paleosol, and two Canarian loess-like deposits to different ages from the Quaternary, we hypothesized that the dust input should be lower (about 33–38%) throughout the early to middle Pleistocene than during the late Quaternary. The Saharan dust input to the Gran Canaria profile in the Pleistocene persisted in spite of climatic variations.

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A biomarker record of Lake El'gygytgyn, far east Russian Arctic: investigating sources of organic matter and carbon cycling during marine isotope stages 1–3

Climate of the Past Discussions ◽

10.5194/cpd-8-4625-2012 ◽

2012 ◽

Vol 8 (5) ◽

pp. 4625-4661

Author(s):

A. R. Holland ◽

S. T. Petsch ◽

I. S. Castañeda ◽

K. M. Wilkie ◽

S. J. Burns ◽

...

Keyword(s):

Organic Matter ◽

Water Column ◽

Atmospheric Carbon Dioxide ◽

Far East ◽

Russian Arctic ◽

Bulk Sediment ◽

Alkanoic Acid ◽

Δ13c Values ◽

Isotopic Signatures ◽

Lake El’Gygytgyn

Abstract. Paleoenvironmental archives in Arctic regions serve as sensitive recorders of past climate change where summer temperatures hover near freezing and small climate variations may exhibit strong threshold-crossing environment responses. Lake El'gygytgyn (Far East Russian Arctic) is a high-latitude crater impact lake that contains a continuous sediment record influenced by neither glaciation nor glacial erosion since the time of impact at 3.58 Ma. Prior research on sediments collected from Lake El'gygytygyn suggest times of permanent ice cover and anoxia corresponding to global glacial intervals, during which the sediments are laminated and are characterized by the co-occurrence of high total organic carbon, microscopic magnetite grains that show etching and dissolution, and negative excursions in bulk sediment organic matter carbon isotope (δ13C) values. Here, we investigate the abundance and carbon isotopic characteristics of lipid biomarkers recovered from Lake El'gygytygn sediments spanning marine isotope stages 1–3, to identify key sources of organic matter (OM) to lake sediments, to establish which compounds and thus OM sources drive the negative δ13C excursion exhibited by bulk sediment OM, and to explore if there are molecular and isotopic signatures of anoxia in the lake during glaciation. We find that during marine isotope stages 1–3, direct evidence for water column anoxia is lacking. A ∼4‰ negative excursion in bulk sediment δ13C values during the local Last Glacial Maximum (LLGM) is accompanied by more protracted, higher magnitude negative excursions in n-alkanoic acid and n-alkanol δ13C values that begin 20 kyr in advance of the LLGM. In contrast, n-alkanes and the C30 n-alkanoic acid do not exhibit a negative δ13C excursion at this time. Our results indicate that the C24, C26 and C28 n-alkanoic acids do not derive entirely from terrestrial OM sources, while the C30 n-alkanoic acid at Lake El'gygytgyn is a robust indicator of terrestrial OM contributions. Overall, our results strongly support the presence of a nutrient-poor water column, which is mostly isolated from atmospheric carbon dioxide during glaciation at Lake El'gygytgyn.

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Detailed insight into Arctic climatic variability during MIS 11 at Lake El'gygytgyn, NE Russia

Climate of the Past Discussions ◽

10.5194/cpd-8-6309-2012 ◽

2012 ◽

Vol 8 (6) ◽

pp. 6309-6339 ◽

Cited By ~ 6

Author(s):

H. Vogel ◽

C. Meyer-Jacob ◽

M. Melles ◽

J. Brigham-Grette ◽

A. A. Andreev ◽

...

Keyword(s):

Climatic Variability ◽

Far East ◽

Ice Cores ◽

Precipitation Anomaly ◽

Last Deglaciation ◽

Lake Productivity ◽

Lake Ice ◽

Thermal Maximum ◽

Lake El’Gygytgyn ◽

The Last Deglaciation

Abstract. Here we present a detailed multiproxy record of the climate and environmental evolution at Lake El'gygytgyn/Far East Russian Arctic during the period 430–395 ka covering the Marine Isotope Stage (MIS) 12/11 transition and the thermal maximum of super interglacial MIS 11. The MIS 12/11 transition at Lake El'gygytgyn is characterized by initial warming followed by a cold reversal implying similarities to the Bølling/Allerød (B/A) to Younger Dryas (YD) pattern of the last deglaciation. Full and remarkably stable interglacial conditions with mean temperatures of warmest month (MTWM) ranging between ca. 10–15 °C, annual precipitation (PANN) ranging between ca. 300–600 mm, strong in-lake productivity, coincide with dark coniferous forests in the catchment, annual disintegration of the lake ice cover and full mixis of the water column. Such conditions persisted for ca. 27 kyrs between ca. 425–398 ka. The Lake El'gygytgyn record closely resembles the climate pattern recorded in Lake Baikal (SE Siberia) sediments and Antarctic ice cores implying strong teleconnections between Northern and Southern Hemispheres during MIS 11. A peak warm period between ca. 418–415.5 ka and a precipitation anomaly at ca. 401 ka at Lake El'gygytgyn, in contrast, appear to be an expression of more regionally confined climate variations.

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A 250 ka oxygen isotope record from diatoms at Lake El'gygytgyn, far east Russian Arctic

Climate of the Past ◽

10.5194/cp-8-1621-2012 ◽

2012 ◽

Vol 8 (5) ◽

pp. 1621-1636 ◽

Cited By ~ 19

Author(s):

B. Chapligin ◽

H. Meyer ◽

G. E. A. Swann ◽

C. Meyer-Jacob ◽

H.-W. Hubberten

Keyword(s):

Oxygen Isotope ◽

Sediment Core ◽

Isotope Composition ◽

Ice Core ◽

Far East ◽

The Arctic ◽

Russian Arctic ◽

Holocene Thermal Maximum ◽

Lake El’Gygytgyn ◽

Mis 5.5

Abstract. In 2003 sediment core Lz1024 was drilled at Lake El'gygytgyn, far east Russian Arctic, in an area of the Northern Hemisphere which has not been glaciated for the last 3.6 Ma. Biogenic silica was used for analysing the oxygen isotope composition (δ18Odiatom) in the upper 13 m long section dating back about 250 ka with samples dominated by one taxa in the <10 μm fraction (Cyclotella ocellata). Downcore variations in δ18O values show that glacial-interglacial cycles are present throughout the core and δ18Odiatom-values are mainly controlled by δ18Oprecipitation. Changes reflect the Holocene Thermal Maximum, the Last Glacial Maximum (LGM) and the interglacial periods corresponding to MIS 5.5 and MIS 7 with a peak-to-peak amplitude between LGM and MIS 5.5 of Δ18O = 5.3‰. This corresponds to a mean annual air temperature difference of about 9 °C. Our record is the first continuous δ18Odiatom record from an Arctic lake sediment core directly responding to precipitation and dating back more than 250 ka and correlates well with the stacked marine δ18O LR04 (r = 0.58) and δD EPICA Dome-C record (r = 0.69). With δ18O results indicating strong links to both marine and ice-core records, records from Lake El'gygytgyn can be used to further investigate the sensitivity of the Arctic climate to both past and future global climatic changes.

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A biomarker record of Lake El'gygytgyn, Far East Russian Arctic: investigating sources of organic matter and carbon cycling during marine isotope stages 1–3

Climate of the Past ◽

10.5194/cp-9-243-2013 ◽

2013 ◽

Vol 9 (1) ◽

pp. 243-260 ◽

Cited By ~ 11

Author(s):

A. R. Holland ◽

S. T. Petsch ◽

I. S. Castañeda ◽

K. M. Wilkie ◽

S. J. Burns ◽

...

Keyword(s):

Organic Matter ◽

Water Column ◽

Atmospheric Carbon Dioxide ◽

Far East ◽

Carbon Isotopic Composition ◽

Russian Arctic ◽

Bulk Sediment ◽

Alkanoic Acid ◽

Δ13c Values ◽

Lake El’Gygytgyn

Abstract. Arctic paleoenvironmental archives serve as sensitive recorders of past climate change. Lake El'gygytgyn (Far East Russian Arctic) is a high-latitude crater impact lake that contains a continuous sediment record influenced by neither glaciation nor glacial erosion since the time of impact 3.58 Ma ago. Prior research on sediments collected from Lake El'gygytgyn suggest times of permanent ice cover and anoxia corresponding to global glacial intervals, during which the sediments are laminated and are characterized by the co-occurrence of high total organic carbon, microscopic magnetite grains that show etching and dissolution, and negative excursions in bulk sediment organic matter carbon isotope (δ13C) values. Here we investigate the abundance and carbon isotopic composition of lipid biomarkers recovered from Lake El'gygytgyn sediments spanning marine isotope stages 1–3 to identify key sources of organic matter (OM) to lake sediments, to establish which OM sources drive the negative δ13C excursion exhibited by bulk sediment OM, and to explore if there are molecular and isotopic signatures of anoxia in the lake during glaciation. We find that during marine isotope stages 1–3, direct evidence for water column anoxia is lacking. A ~4‰ negative excursion in bulk sediment δ13C values during the Local Last Glacial Maximum (LLGM) is accompanied by more protracted, higher magnitude negative excursions in n-alkanoic acid and n-alkanol δ13C values that begin 20 kyr in advance of the LLGM. In contrast, n-alkanes and the C30 n-alkanoic acid do not exhibit a negative δ13C excursion at this time. Our results indicate that the C24, C26 and C28 n-alkanoic acids do not derive entirely from terrestrial OM sources, while the C30 n-alkanoic acid at Lake El'gygytgyn is a robust indicator of terrestrial OM contributions. Overall, our results strongly support the presence of a nutrient-poor water column, which is mostly isolated from atmospheric carbon dioxide during glaciation at Lake El'gygytgyn.

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