English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The 3.6 Ma sediment record of Lake El'gygytgyn/NE Russia, Far East RussianArctic, represents the longest continuous climate archive of the terrestrialArctic. Its elemental composition as determined by X-ray fluorescencescanning exhibits significant changes since the mid-Pliocene caused byclimate-driven variations in primary production, postdepositional diageneticprocesses, and lake circulation as well as weathering processes in itscatchment.  During the mid- to late Pliocene, warmer and wetter climatic conditions arereflected by elevated Si / Ti ratios, indicating enhanced diatom productionin the lake. Prior to 3.3 Ma, this signal is overprinted by intensifieddetrital input from the catchment, visible in maxima of clastic-relatedproxies, such as K. In addition, calcite formation in the early lake historypoints to enhanced Ca flux into the lake caused by intensified weathering inthe catchment. A lack of calcite deposition after ca. 3.3 Ma is linked to thedevelopment of permafrost in the region triggered by cooling in themid-Pliocene.  After ca. 3.0 Ma the elemental data suggest a gradual transition toPleistocene-style glacial–interglacial cyclicity. In the early Pleistocene,the cyclicity was first dominated by variations on the 41 kyr obliquity bandbut experienced a change to a 100 kyr eccentricity dominance during themiddle Pleistocene transition (MPT) at ca. 1.2–0.6 Ma. This clearlydemonstrates the sensitivity of the Lake El'gygytgyn record to orbitalforcing.  A successive decrease of the baseline levels of the redox-sensitive Mn / Feratio and magnetic susceptibility between 2.3 and 1.8 Ma reflects an overallchange in the bottom-water oxygenation due to an intensified occurrence ofpervasive glacial episodes in the early Pleistocene. The coincidence withmajor changes in the North Pacific and Bering Sea paleoceanography at ca. 1.8Ma implies that the change in lake hydrology was caused by a regional coolingin the North Pacific and the western Beringian landmass and/or changes in thecontinentality. Further increases in total organic carbon and total nitrogencontent after ca. 1.6 Ma are attributed to reduced organic matter decay inthe sediment during prolonged anoxic periods. This points to more extensiveperiods of perennial ice coverage, and thus, to a progressive shifts towardsmore intense peak glacial periods.  In the course of the Pleistocene glacial–interglacial sequence eightso-called "super-interglacials" occur. Their exceptionally warm conditionsare reflected by extreme Si / Ti peaks accompanied by lows in Ti, K, andFe, thus indicating extraordinary high lake productivity

climate of the past

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