Mineralogy of Holocene bog-iron ore in northern Belgium
Goethite, siderite, ferrihydrite, oxidized blue vivianite and a practically X-ray amorphous oxidation product of vivianite were identified as the dominant iron components of the bog-iron ores.
The AA. describe the types and forms of iron sulfide minerals in magnetotactic bacteria and their possible biogeochemical and palaeomagnetic significance.
Iron deposits and microorganisms in saline sulfidic soils with altered soil water regimes in South Australia
Biomineralization processes of iron and manganese. Modern and ancient environments
Australia ; Biogeochemistry ; Geochemistry ; Iron ; Micro-organism ; Microstructure ; Mineralization ; Soil ; Soil properties ; South Australia
The objectives of this paper are to: i) describe the types of gelatinous, red-brown, iron-rich precipitates found in waterlogged surface layers of recently-formed, saline, sulfidic soils and compare these precipitates with those that befoul
boreholes in the same area and ii) elucidate the biogeochemical processes of iron mineral formation in both the gelatinous red-brown iron-rich precipitates formed during the wet season and yellowish iron-rich crusts formed in the dry season.
Seasonal changes in iron transport and nature of dissolved organic matter in a humic river in northern Finland
Finland ; Geochemistry ; Hydrology ; Iron ; Organic materials ; Seasonal variation ; Streams ; Water quality
Changes in the concentration of iron and dissolved organic matter (DOM), and in the colour and fluorescence properties in the River Küminkijoki were investigated as functions of the seasonal flow regime over a two-year period. Discussion
Mineralogy of iron oxides in two soil chronosequences of Central Spain
The AA. show how slight differences in the pedoenvironment give contrasting iron oxide mineralogies in the soils of two geographically close river terrace sequences of central Spain.
Iron oxide accumulations in tertiary sediments of the Roupar Basin, Galicia, NW Spain
In this article the AA. describe the chemistry and mineralogy of the iron-rich deposits in the Roupar Basin and suggest a possible mechanism for their formation.
Iron sulfide minerals may be formed in tidal marshes following microbial reduction of sulfate to sulfide. Sulfate reduction requires certain necessary factors including sulfate reducing bacteria, organic matter, low redox potential, and sulfate
Late Archean metamorphic Banded Iron-Formations of Bababudans of Karnataka, India
Biomineralization processes of iron and manganese. Modern and ancient environments
Archaean ; Diagenesis ; Hydrothermal ; India ; Iron ; Karnataka ; Manganese ; Metamorphism ; Mineralization ; Mineralogy
The present mineralogical and field aspects of the mixed oxide and oxide Banded Iron-Formations (BIFs) of Bababudans are presented in order to reconstruct depositional environments in which mineralization took place. An attempt is made to show
Biomineralization processes of iron and manganese. Modern and ancient environments
Biogenic process ; Biogeochemistry ; Geochemistry ; Iron ; Manganese ; Micro-organism ; Mineralization ; Palaeogeography ; Pedogenesis
range from intracellular to million ton ore bodies. The research thrusts are on modern and on ancient environments because similar biogeochemical mechanisms may have been involved in the formation of the earliest laminated rocks, the banded iron
New evidence of an organic contribution to manganese precipitation in iron-formation and review of sedimentary conditions in the Cuyuna North Range, Minnesota
Biomineralization processes of iron and manganese. Modern and ancient environments
Biogenic process ; Biogeochemistry ; Geochemistry ; Iron ; Manganese ; Microstructure ; Minnesota ; Sedimentary ; United States
The Cuyuna North Range was chosen as a study area because it has produced both iron ore and manganiferous iron ore from the Trommald Formation. Standard petrographic thin sections of this formation were studied for evidence of mechanisms involved
in the precipitation of manganese. The microstructures suggest that microbial precipitation may have been a dominant factor in the precipitation of both iron and manganese in the Trommald Formation.
Anthropogenically-triggered iron pan formation in some Irish soils over various time spans
Human impact ; Ireland ; Iron ; Land use ; Peat ; Pedogenesis ; Podsolisation ; Soil properties
This paper synthesises existing and new research into the influence of man on the development of iron pans in Irish soils. The common theme in this work is the influence of organic matter, directly or indirectly, on the fate of iron and on its
concentration into seams of differing age and degree of robustness, thickness and durability. The data refer to 5 locations in Ireland where addition of organic matter seems to be the only pedogenic factor likely to influence iron accumulation. In all instances
, the development of an iron pan is a relatively modern process, superimposed on an earlier generation of distinctly different horizons.
Geomorphic features and associated iron oxides of the Dallol Bosso of Niger (West Africa)
This paper discusses some of the pathways of iron-oxide formation and accumulation in the Sahelian environment using the Dallol Bosso region of Niger as an example.
The iron settlement at De Panne-Westhoek. Ecological and geological context
After a palynological analysis a humic layer has been dated through the C-method. The age is 2660 100 B.P. (bottom) and 1965 110 B.P. (top). This dating matches the Iron Age material that has been found. The knowledge of the ecology