In contrast, U and Cu distributions differ markedly in a sample containing abundant coffinite; U mineralization is overprinting the ore textures, as well as occupying late fractures (Figure 1(b)).
Selection of Thermodynamic Properties for Aqueous U Chloride and Fluoride Complexes, Uraninite, and Coffinite
Coffinite and brannerite are both more abundant than uraninite (the only U mineral predicted to precipitate in our model).
Hence, precipitation of coffinite and brannerite versus uraninite are controlled by temperature and by the presence of suitable microenvironments .
Pring, "Chemical and textural interpretation of late-stage coffinite and brannerite from the Olympic Dam IOCG-Ag-U deposit," Mineralogical Magazine, vol.
Baghal Chur deposit###0.05%###Pitchblende and Coffinite
The primary uranium minerals are uraninite and coffinite
but numerous secondary uranium minerals have been formed as a result of the weathering processes: yellow gummites, autunite, metaautunite, torbernite, saleeite, uranotyle, ianthinite and uranopilite (Arribas, 1975).
is assumed to be precipitated in the reducing part of the system.
8) is connected with the origin of uranium mineralization and a higher concentration of HREE in coffinite. Albitization of granites is in some cases accompanied by the origin of the lanthanide tetrad effect.
The HREE enrichment in episyenites can be explained by the formation of HREE-bearing uranium minerals (coffinite, uraninite; Cathelineau, 1987; Fayek and Kyser, 1997).
The main uranium-ore stage characterized by the formation of coffinite and pitchblende was dated by the U/Pb method (Anderson et al., 1989).
The ore stage was marked by the formation of coffinite and pitchblende, together with small amount of authigenic chlorite, hydrated titanium oxide (leucoxene?) and pyrite.