Late-Hercynian gold-bearing arsenic-polymetallic mineralization within Saxothuringian zone in the Polish Sudetes, Northeast Bohemian Massif

摘要

Late-Hercynian gold-bearing arsenic-polymetallic deposits in the Sudetes post-date regional metamorphism of host rocks (amphibolite or greenschist facies), early phases of orogenic deformation, and are locally related to granitoid intrusions and/or regional shear zones. In general, the Au-bearing As (Fe-Cu-S) mineralization followed a contact-metasomatic stage of oxide mineralization (Zloty Stok and Czarnow deposits) and preceeded hydrothermal base metal sulfide stages. Fluid inclusion studies in quartz from rocks, hosting impregnated auriferous arsenopyrite mineralization, suggest crystallization temperatures c.a. 400℃ and in quartz from Au-bearing arsenopyrite/sulfide quartz veins at 320-230℃, from fluids with salinity from 1 to 14 wt % equiv. NaCl. The δ~(34)S values of sulfides range from -5 to 5 per thousand , indicating a postmagmatic hydrothermal origin with local crustal contribution. Geochemical studies revealed a high variability of correlation between Au and other elements. The present data suggests that the deposits formed in different settings such as orogenic deposits (accreted terranes), intrusion related deposits (with Lower Paleozoic VMS contributions) and porphyry and/or epithermal deposits (continental arc).