Chemical and mineralogical characteristics and origin of placer gold from fluvial deposits of Żeliszowski Creek (North Sudetic Basin, SW Poland)

Abstract

Chemical and mineralogical analyses of individual detrital gold grains collected from recent channel-fill deposits of Żeliszowski Creek, located between the towns of Lwówek Śląski and Bolesławiec, were made, together with determination of the Au-bearing mineral assemblages and indication of probable source areas. The analysed gold grains have admixtures of silver, mercury and copper. Numerous inclusions of ore minerals, mainly Cu, Hg selenides and Cu, Pb and Bi sulphides were found in the detrital gold grains. These minerals are characteristic of Permian, Au-bearing, red-bed successions in the region, and of quartz veins of the Kaczawa Metamorphic Complex. This supports the hypothesis of a polygenetic origin for the Lower Silesian alluvial gold-bearing deposits. The applied research methodology may be successfully used in polymetallic ore deposit prospecting more generally.