Mi. Pascua et al., SN-GE-CD-CU-FE-BEARING SULFIDES AND SULFOSALTS FROM THE BARQUILLA DEPOSIT, SALAMANCA, SPAIN, Canadian Mineralogist, 35, 1997, pp. 39-52
Sn-Ge-Cd-Cu-Fe mineralization is observed in the Fuentes Villanas mine
, which exploits the hydrothermal vein deposit of Barquilla, Salamanca
, Spain. Two associations are present, one consisting of cassiterite,
cernyite, greenockite, tetrahedrite, herzenbergite and minor chalcopyr
ite, Ag-Pb-Bi-bearing sulfosalts, galena and native bismuth, in the ve
ins; the other involves chalcopyrite, stannite, stannoidite, mawsonite
, tetrahedrite, cadmian briartite, bornite, mohite, native bismuth, bi
smuthinite and digenite in the altered host-rock close to the veins. T
he first one crystallized before an intense episode of sericitic alter
ation, whereas the second is contemporaneous with it The crystallizati
on sequence of Sn-bearing minerals proposed is: cassiterite --> herzen
bergite --> cernyite --> stannoidite --> mawsonite. Available experime
ntal data suggest that these minerals crystallized in a sequence contr
olled by the increase of S fugacity or decrease of temperature (or bot
h). The germanium content of cadmian briartite probably was picked up
from the host rocks by migrating fluids.