New data on the Holocene evolution of the Dvina Bay (White Sea)

Postglacial sedimentation in the White Sea (northwestern Russia) reconstructed by integrated microfossil and geochemical data

“…According to microfossil data, during the mid-Holocene climatic optimum (6000–7500 cal yr BP), there was an increase in duration of the vegetation period and the surface water temperature in the White Sea to higher values than that observed nowadays (up to 12–14°C; Novichkova et al, 2017). This is also reflected in the distribution of the C org and BSi in the studied core.…”

“…As a result, the environmental conditions became more favorable for the bioproduction processes in the surface White Sea waters (Polyakova et al, 2014). However, in the first half of the Boreal period, both the microfossil and lithologic-biogeochemical data allowed to reconstruct the sea-ice conditions (up to 10 months in the year by data of; Novichkova et al, 2017). Thus, an input of terrigenous matter was the main factor of sedimentation in the early Holocene, which was confirmed by a highest content of such lithophile elements as Al, Mg, and K, as well as the heavy metal Cr, in this part of the core (300–335 cm), whereas the percentage of the trace metals’ mobile forms was low.…”

“…Over the past decade, new data on the modern sedimentation processes and the geologic history of the White Sea have been obtained in the framework of the long-term multidisciplinary project “The White Sea System” (Lisitsyn and Demina, 2018). The new study of the White Sea paleoenvironment by biogeochemical methods was based on the accelerator mass-spectrometry (AMS) 14 C dating and complex microfossil analysis of diatoms and aquatic palynomorphs (Polyakova et al, 2003, 2014; Novichkova and Polyakova, 2007, 2013; Novichkova et al, 2017). Various biogeochemical processes that took place at the initial stage of sedimentation of the White Sea, including mobilizing of the trace elements in the water column and the processes of early diagenesis, have been also considered (Budko et al, 2017; Demina et al, 2017, 2018a, b).…”