Partitioning of trace elements in the process of early diagenesis of bottom sediments in the White Sea

Geochemical Signatures of Paleoclimate Changes in the Sediment Cores from the Gloria and Snorri Drifts (Northwest Atlantic) over the Holocene-Mid Pleistocene

“…In the western Arctic Ocean sediment cores, enriched in the Mn brown units were attributed to the glacial intervals, while the clear mechanisms of such correlation is still speculative [26]. In the subpolar White Sea (Northwestern Russia), a change in the Mn/Fe ratio in mobile forms (exchangeable and oxyhydroxides) reflects the rapid oxidation of Mn (II) in the uppermost layers of the cores, as well as a slowdown of diagenetic reduction of the oxidized forms of Fe and Mn at a depth of~130 cm [30,53].…”

“…Manganese, as a redox-sensitive element, was used in the sediments of the Lomonosov Ridge in the Arctic Ocean to determine the conditions of anoxia caused by ice cover [26]. The Mn/Fe ratio serves as a proxy of redox conditions and post-sedimentary changes in bottom sediments, as soon as an anoxia leads to a change in the Mn/Fe ratio and contents of Mn-related and some chalcophile metals in the sedimentary cores [27][28][29][30]. The Sr/Ca and Rb/Sr ratios in the biogenic carbonate sediments of the South Atlantic were applied as a geochemical proxy of climatic changes: Glacial periods are characterized by high Sr/Ca values, while interglacials are characterized by lower ones [31].…”

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

“…Some features that have been revealed in the chemical elements’ behavior in the surface (0–50 cm) sediments of the White Sea (Demina et al, 2017) are also characteristic for the deeper sediment layers formed during the Holocene. Such metals as Cd and Mn continue their active geochemical migration even in the ancient sediments, although the geochemical activity of Mn decreases and portion of the Mn lithogenic form progressively increases.…”

“…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). The data on organic carbon (C org ) and biogenic silica (BSi) are widely used as geochemical indicators of paleoproductivity when studying the oceanic paleoenvironment of a low-carbonate marine basin (Regueneau et al, 1996, 2001; Kim et al, 2014).…”

“…Over the past 20 yr, an interest in studying chemical element speciation in marine ecosystems has arisen because of the ecotoxicological effects of heavy metals and their bioavailability for living organisms (Kot and Namiesnik, 2000; Nemati et al, 2011; Grotti et al, 2013; Fernandes and Nayak, 2015). On the other hand, the geochemical cycles of heavy metals in the modern sedimentary processes are of importance in regard to chemical element speciation (Poulton and Raiswell, 2002; Demina et al, 2006, 2017, 2018a; Raiswell and Сanfield, 2012; Koukina and Vetrov, 2013; Mamindy-Pajany et al, 2013), while the data on sediment cores are severely limited.…”