Аннотация:first_pagesettingsOrder Article ReprintsOpen AccessArticleSr and Nd Isotopes in Mineral Fractions of Ferromanganese Crusts from the Northernmost Pacificby Pavel Mikhailik 1,*,Irina Vishnevskaya 1,2,Liang Yi 3ORCID,Natalia Soloshenko 4 andVadim Pellinen 5ORCID1Far East Geological Institute, FEB RAS, Vladivostok 690022, Russia2Vernadsky Institute of Geochemistry and Analytical Chemistry, RAS, Moscow 119334, Russia3State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China4Zavaritsky Institute of Geology and Geochemistry, UB RAS, Ekaterinburg 620010, Russia5Institute of the Earth’s Crust, SB RAS, Irkutsk 644033, Russia*Author to whom correspondence should be addressed.J. Mar. Sci. Eng. 2023, 11(10), 1920; https://doi.org/10.3390/jmse11101920Submission received: 23 August 2023 / Revised: 24 September 2023 / Accepted: 25 September 2023 / Published: 5 October 2023(This article belongs to the Section Geological Oceanography)Downloadkeyboard_arrow_down Browse Figures Review Reports Versions NotesAbstractA study of the isotopic compositions of neodymium and strontium in four mineral fractions of the hydrogenous ferromanganese crusts of the northernmost Pacific has been carried out for the first time. The relationship of the 87Sr/86Sr ratio and εNd value of the residual fraction in heterochronous layers of the ferromanganese crusts have shown that the sources of detrital matter are from rock weathering by the Yukon River, the Kuskokwim River, the Anadyr River and the rivers of Kamchatka. The amount of aluminosilicate impurity does not affect the isotopic compositions of the chemogenic (loosely bound, Mn oxides or manganese, hydrous Fe oxides or ferrous) fractions. The decreased εNd value in the ferrous fraction seems to be related to the presence of rare earth element (REE) phosphate complexes in seawater. The increase in those complexes is a consequence of melt waters entering the ocean during warming periods. Our data indicate that the carbonate REE complexes are not the dominant form of the REEs in the northernmost Pacific, which leads to the fact that the neodymium isotopic compositions of the manganese and ferrous fractions of hydrogenous ferromanganese crusts are different. A decrease in εNd value in the ferrous fraction may be a marker of a local increase in the surface water bioproductivity. Our data also show that the increase of the REE in the ferrous fraction relative to the manganese fraction does not reflect the participation of hydrothermal matter in the formation of mixed hydrogenous–hydrothermal crusts but is a consequence of an increase in the REE phosphate complexes.