Dubinin, A. V. and Sval'nov, V. N. (2000): Geochemistry of rare earth elements in ferromanganese micro- and macronodules from the Pacific nonproductive zone
Leg/Site/Hole:
Related Expeditions:
DSDP 5 DSDP 5 35
Identifier:
ID:
2003-071286
Type:
georefid
Creator:
Name:
Dubinin, A. V.
Affiliation:
Russian Academy of Sciences, Shirshov Institute of Oceanology, Moscow, Russian Federation
Role:
author
Name:
Sval'nov, V. N.
Affiliation:
Role:
author
Identification:
Title:
Geochemistry of rare earth elements in ferromanganese micro- and macronodules from the Pacific nonproductive zone
Year:
2000
Source:
Lithology and Mineral Resources
Publisher:
MAIK Nauka/Interperiodica Publishing, Birmingham, AL, United States
Volume:
35
Issue:
6
Pages:
520-537
Abstract:
Ferromanganese micro- and macronodules in eupelagic clays at Site 35 of the South Basin were examined in order to check the REE distribution during the ferromanganese ore formation in nonproductive zones of the Pacific Ocean. We studied host sediments and their labile fraction, ferromanganese micronodules (fractions 50-100, 100-250, 250-500, and >500 mu m) from eupelagic clays (horizons 37-40, 105-110, 165-175, and 189-190 cm), and buried ferromanganese micronodules (horizons 64-68, 158-159, and 165-166 cm). Based on phase analysis data, the anomalous REE enrichment of eupelagic clays from Site 35 is related to the accumulation of rare earth elements in iron hydroxophosphates. The Ce concentration, generally linked to manganese oxyhydroxides, is governed by the oxidation of Mn and Ce in oceanic surficial waters. Micronodules (Mn/Fe = 0.7-1.6) inherit compositional features of the labile fraction of sediments. The Ce, Co, and Th concentrations depend on the micronodule dimension. The enrichment of micronodules in hydrogenic or hydrothermal substance is governed by their dimension and the dominant source of suspended oxyhydroxide material. The study of buried ferromanganese micronodules revealed general regularities in the compositional evolution of oxyhydroxide matrices of ferromanganese micro- and macronodules. The compositional variation of micro- and macronodules, relative to the labile fraction of sediments, in the Pacific nonproductive zone dramatically differs from the pattern in bioproductive zones, where micronodule compositions in larger fractions are similar to those in associated macronodules and labile fractions of the host sediment as a result of the more intense suboxidative diagenesis.
Language:
English
Genre:
Serial
Rights:
URL:
Coverage: Geographic coordinates: North:40.4026 West:-149.5800 East:
-127.2828 South:-29.3600
Keywords: Oceanography; Geochemistry of rocks, soils, and sediments; concentration; Deep Sea Drilling Project; diagenesis; DSDP Site 35; East Pacific; ferromanganese composition; geochemistry; Gorda Rise; Leg 5; metals; mineralization; nodules; North Pacific; Northeast Pacific; Pacific Ocean; rare earths; sedimentation; South Pacific;
.