Multiple fluid sources/pathways and severe thermal gradients during formation of the Jilove orogenic gold deposit, Bohemian Massif, Czech Republic
Abstrakt
The Jílové deposit in the central part of the Bohemian Massif represents a vein to stockwork type of orogenic-type gold deposit. It is hosted by Neoproterozoic rocks of the Jílové Belt and by various magmatic dikes related to the ~355 to ~335 Ma Central Bohemian Plutonic Complex.
The deposit offered an exceptional opportunity to trace O, C, S and Sr stable isotope evolution of parent fluids based on combined mineralogical and geochemical study of carbonate, quartz, scheelite, and sulfide minerals, which represent six stages of mineralization, including the gold-bearing event. Age determination of hydrothermal muscovite (related to stage 2) via 40Ar/39Ar indicated an age of 339.0 ± 1.5 Ma for the quartz veins.
The mineralization is essentially coeval with the late intrusive phases of the Central Bohemian Plutonic Complex (i.e. the ultrapotassic suite) and with late-orogenic large-scale tectonic movements at the boundary between the two crustal terranes (Teplá-Barrandian and Moldanubian).