Инд. авторы:	Savelyeva O.L., Savelyev D.P., Palesskii S.V.
Заглавие:	Carbonaceous Rocks in Cretaceous Deposits of the Kamchatsky Mys Peninsula: Geochemistry, Metal Accumulation, and Sedimentation Conditions
Библ. ссылка:	Savelyeva O.L., Savelyev D.P., Palesskii S.V. Carbonaceous Rocks in Cretaceous Deposits of the Kamchatsky Mys Peninsula: Geochemistry, Metal Accumulation, and Sedimentation Conditions // Russian Journal of Pacific Geology. - 2021. - Vol.15. - Iss. 3. - P.211-223. - ISSN 1819-7140. - EISSN 1819-7159.
Внешние системы:	DOI: 10.1134/S1819714021030076; WoS: 000664493900004;
Реферат:	eng: Carbonaceous beds have been studied in the Cretaceous paleo-oceanic deposits of Eastern Kamchatka; their origin relates to the anoxic oceanic events. In the carbonaceous rocks, the contents of trace elements and noble metals: Ba, Cu, Ni, Zn, Mo, V, U, Y, Au, rare-earth elements and platinoids are increased compared to host jaspers and limestones. In particular, in ashed carbonaceous rocks, the contents of Au and Pt reach 0.8 and Pt 2.1 g/t, respectively. The Mo/Mn and V/(V + Ni) geochemical indices indicate the accumulation of carbonaceous deposits in euxinic conditions. The significant authigenic Ba fraction points to the high bioproductivity in the upper part of the water column. High bioproductivity and euxinic conditions of sedimentation caused the enrichment of carbonaceous rocks in many trace elements. Phosphorus was trapped in the sediments with bone debris, which subsequently sorbed rare-earth elements and yttrium from seawater during its fossilization. Copper, zinc, and vanadium are associated with the Fe-sulfide phase (framboidal pyrite). Noble metals accumulated during sedimentation and early diagenesis and were deposited with organic matter and/or directly from seawater. In carbonaceous rocks, they appear to be in the form of organometallic compounds or impurity in framboidal pyrite. The sedimentation occurred at the top of a seamount in the Pacific Ocean. The studied deposits are similar to Cretaceous sediments formed at the tops of intraoceanic seamounts of the northwestern Pacific, where carbonaceous beds are also present in the sections. Organic-rich sediments were deposited within the oxygen minimum zone during periods of maximum bioproductivity of plankton.
Ключевые слова:	COMPLEX; IRIDIUM; ISOTOPE; SILICITES; ENRICHMENT; MINERALIZATION; EASTERN KAMCHATKA; OCEANIC ANOXIC EVENT; PLATINUM-GROUP ELEMENTS; Kamchatka; euxinic conditions; bioproductivity; noble metals; carbonaceous rocks; RHENIUM;
Издано:	2021
Физ. характеристика:	с.211-223