Złoto okruchowe i inne minerały ciężkie w osadach potoku Maruszka k. Burgrabic (Sudety Wschodnie)

Abstract

Detrital gold and others heavy minerals in alluvial deposits of Maruszka Stream near Burgrabice (East Sudety Mts., SW Poland).Summary. Two main heavy mineral associations were found in the studied sediments: magnetite–ilmenite and garnet–zircon–pyroxene. The parental rocks for those minerals were rocks from a metamorphic complex: gneisses, amphibolites, quartzities and crystalline limestones. Furthermore, the detrital gold was found in the alluvial deposits of Maruszka stream. The shape of most gold grains is discoidal or elliptical and they show various mechanical deformations (scratches, furrows, impact, and sandwich structures). The most significant primary gold source are amphibolites, which occur in Devonian quartzities and quartz schists of Vrbno group. The morphology, surface textures, and chemical composition of the gold particles suggest that the majority of gold was transported presumably in a suspended form as flakes, scales, and small grains. Gold could have also been dissolved and transported as complex compounds, colloidal solutions or suspensions. Moreover, some of the gold could have been redeposited and entered the Maruszka stream directly as a result of erosion of the Neogene, Gozdnica Series -like sediments and of Quaternary clays.