Rare and Trace Elements in the Modern Bottom Sediments of the Barents Sea

Abstract

The article presents a brief lithological description of modern bottom sediments collected in the Barents Sea during Cruise 67 of the R/V Akademik Mstislav Keldysh at test sites: (1) “Pechora Sea”; (2) “Western slope of the Kanin Shoal”; (3) “Central Barents Sea (Shtokman area)”; (4) “Russkaya Gavan Fjord”; (5) “Medvezhinsky Trough”; (6) area south of Spitsbergen; (7) “Kola Meridian”; (8) “Spitsbergen–Franz Josef Land Archipelago”; (9) “Cambridge Strait.” Distribution of Cr, Ni, Cu, Zn, Cd, and Pb in samples of modern bottom sediments (pelitic, aleuritic–pelitic and sandy–aleuritic–pelitic ooze) is compared with background concentrations and contents of these elements in the Post-Archean Australian Shale (PAAS). The data obtained are consistent with the notion that the distribution of heavy metals and other elements in bottom sediments is controlled primarily by the global geochemical background. Relationship of Sc, V, Cr, Ni, Y, Zr, Nb, Mo, Hf, Th, U, and REE concentrations with contents of the fine pelite (<0.001 mm) fraction and organic carbon (Corg) is considered. It was found that most of these elements are characterized by a moderate positive correlation with the fine pelite fraction in samples. Based on the coefficient of their correlation with the Corg content, the above elements can be assigned to three groups with: (1) moderate positive correlation, (2) low positive correlation, and (3) virtual absence of correlation. Distribution of element-indicators of the source rock composition (Sc, Th, Co, Cr, La, and Sm) and REE in modern bottom sediments of the Barents Sea indicates that the majority of them are geochemically mature, and they were sourced from the Kola Peninsula and Spitsbergen (?).Bottom sediments of the Cambridge Strait are represented by geochemically less mature material, which, apparently, entered the sea as a result of erosion of rocks of the Franz Josef Land Archipelago.