Diatoms and their abundances in the Late Holocene sediments of Core LV77-3-1 from the southern part of Chukchi Sea

• Main Authors: Tsoy, Ira B, Obrezkova, Maria S
• Format: Dataset
• Language: English
• Published: PANGAEA 2019
• Subjects: Actinocyclus curvatulus; Actinocyclus ingens; Actinocyclus ochotensis; Actinocyclus octonarius; Actinocyclus octonarius var. tenellus; Actinocyclus oculatus; Actinocyclus subtilis; Actinoptychus senarius; Amphora proteus; Amphora sp.; Arachnoidiscus ehrenbergii; Aulacodiscus affinis; Aulacoseira praegranulata forma curvata; Aulacoseira praegranulata var. praeislandica; Azpeitia tabularis; Bacillaria socialis; Bacterosira bathyomphala; Bacterosira constricta; Caloneis brevis; Caloneis westii; Chaetoceros aff. coronatus; Chaetoceros debilis; Chaetoceros diadema; Chaetoceros didymus; Chaetoceros furcellatus; Chaetoceros holsaticus; Chaetoceros ingolfianus; Chaetoceros lorenzianus; Chaetoceros mitra; Chaetoceros radicans; Chaetoceros sp.; Chaetoceros spp.; Chaetoceros teres; Cocconeis costata; Cocconeis scutellum; Cocconeis vitrea; Coscinodiscus argus; Coscinodiscus asteromphalus; Coscinodiscus marginatus; Coscinodiscus obscurus; Coscinodiscus oculus-iridis; Coscinodiscus perforatus var. cellulosus; Coscinodiscus radiatus; Coscinodiscus radiatus var. borealis; Cosmiodiscus insignis; Cymbella spp.; Delphineis kippae; Delphineis surirella; Depth; bottom/max; Bering Strait; Chukchi; Chukchi Sea
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.904147; https://doi.org/10.1594/PANGAEA.904147

Diatoms from 87 sediment samples of the Core LV77-3-1 collected in southern part of Chukchi Sea were examined to reconstruct paleoenvironments of last millennia and correlate with sediment geochemistry data obtained from the same Core. Diatoms in Core Lv77-3-1 are represented by 161 species belonging to 61 genus (table 1). The largest number of species is characteristic of the genera Chaetoceros (15 taxa), Navicula (12), Thalassiosira (10), Coscinodiscus (8), Diploneis (8), Actinocyclus (7). Most species are marine, among which are 62 planktonic, benthic - 63 species. Considerable amount of freshwater (24 taxa) and extinct (12 taxa ) species are encountered but they are single. Analysis of diatoms on a detailed age model showed the periodicity of sedimentation in the zone of influence of the Pacific waters of the Chukchi Sea in the Late Holocene, which is characterized by alternation of relatively cold and warm epochs. The reconstructed changes do not fully reflect the global climate changes of the late Holocene. It is assumed that a possible cause of the discrepancy between ice conditions and global temperature changes is the inflow of warm Pacific waters through the Bering Strait, which increases the duration of the ice-free period.