Antipathetic magnesium-manganese relationship in basal metalliferous sediments

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doi: 10.1016/0009-2541(81)90088-7
Author(s): Bloch, S.
Author Affiliation(s): Primary:
Univ. Okla., Geol. Survey, Norman, OK 73019, United States
Volume Title: Chemical Geology
Source: Chemical Geology, 33(1-2), p.101-113. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0009-2541 CODEN: CHGEAD
Note: In English. 26 refs.; illus. incl. 3 tables
Summary: Basal metalliferous sediments from three DSDP sites are mixtures of pelagic clay, biogenic ooze, and a metalliferous component of hydrothermal origin, which displays a strong inverse relationship between Mg and Mn. Mg is most likely in sepiolite, whereas Mn occurs almost exclusively as an oxide. Precipitation of the Mg-rich phase is favoured by high flow rates and limited mixing with sea-water. Under such conditions much of the hydrothermal Mn2+, with its slow oxidation kinetics, may escape to the free water column. In highly-diluted hydrothermal fluids, dissolved silica is diluted below saturation with respect to sepiolite. The separation of the Mn and Mg phases may be further compounded by hydraulic fractionation.
Year of Publication: 1981
Research Program: DSDP Deep Sea Drilling Project
Key Words: 02 Geochemistry; Absorption spectroscopy; Alkaline earth metals; DSDP Site 77; DSDP Site 80; DSDP Site 81; Deep Sea Drilling Project; Equatorial Pacific; Geochemistry; Hydrothermal conditions; Iron; Leg 9; Magnesium; Manganese; Marine sediments; Metals; Mineral assemblages; Pacific Ocean; Sediments; Silica; Spectra; X-ray fluorescence spectra
Coordinates: N002809 N002809 W1331307 W1331307
Record ID: 1982059302
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from Mineralogical Abstracts, United Kingdom, Twickenham, United Kingdom, Reference includes data from PASCAL, Institute de l'Information Scientifique et Technique