Postma D (1980) Formation of siderite and vivianite
and the pore-water composition of a recent bog sediment in Denmark.
is a widespread mineral in lacustrine sediments (see samples of world occurrences in Fagel et al.
It is also possible that phosphate minerals did not form because not enough iron was available for precipitation of variscite, strengite, or vivianite
. The Seabrook soils at the research site were located near the front of the drainfield trenches and between the OWS and the estuary.
However, with the passage of time, the remaining "cornflower blue" mineral inclusions also found in these units, which may be vivianite
crystals, retained their coloration and, if anything, had only deepened in color.
For example, Ptacek (1998) describes the elevated presence of vivianite
, an amorphous ferric phosphate, which has been formed following dissolution and subsequent precipitation in the more reduced lower zones of the aquifer.
Blue Fe- and P-rich authigenic mineral inclusions formed of vivianite
were also determined in this level.
Irish Stallion Farms EBF Cooley Fillies & Mares Stakes 8.00 Dundalk 1m, Listed ATR VVCARD, page 76 DUNDALK has long been a happy hunting ground for Michael Halford and he runs four - Petticoat, Surrounding, Terzetto and Vivianite
- in today's mile feature.
This daughter of Bated Breath shaped with plenty of promise on her belated debut at the Curragh in late July, finishing third, beaten less than four lengths, behind Park Bloom and subsequent winner Vivianite
We believe this is the first reported occurrence of vivianite
in western Tennessee.
The standards selected for Fe were fayalite ([Fe.sub.2]Si[O.sub.4]), magnetite ([Fe.sub.3][O.sub.4]), goethite (FeOOH), siderite (FeC[O.sub.3]), vivianite
([Fe.sub.3](P[O.sub.4]).8[H.sub.2]O), hematite ([Fe.sub.2][O.sub.3]), green rust-Cl ([(Fe, [Mg.sup.2+]).sub.6] [([Fe.sup.3+]).sub.2][(OH).sub.18].4[([H.sub.2]O).sub.18]Cl), and green rust-S[O.sub.4] ([(Fe,[Mg.sup.2+]).sub.6] [([Fe.sup.3+]).sub.2][(OH).sub.18].4[([H.sub.2]O).sub.18]S[O.sub.4]).
During operations in the 1950s, the mine produced exceptional specimens of the phosphates ludlamite and vivianite
, which currently grace many public and private collections worldwide.
Thin section and scanning electron microscope images reveal that these cleavages are defined by microveins of calcite, gypsum, and montmorillonitic clays with hematite and vivianite
, and that there is some evidence for silica dissolution.