The dual geochemical character of paragenesis and fractionation between gold, arsenic and antimony in micro-disseminated gold deposits in southwestern Guizhou is discussed in terms of spatial distribution of independe...The dual geochemical character of paragenesis and fractionation between gold, arsenic and antimony in micro-disseminated gold deposits in southwestern Guizhou is discussed in terms of spatial distribution of independent deposits, lateral and vertical enrichment, mineralization stage and factor and correlation analyses. Thermodynamic calculations of solubility and speciation of gold and antimony minerals indicate that gold is transported in hydrothermal solution as Au(HS) 2and antimony is mainly as Sb(OH)30 although HSb2S4 may be of increasing importance in acidenvironment at low temperatures during the late stage of mineralization. Changes in physico-chemical conditions hold the key to the association and fractionation between gold and antimony. Gold and antimony response differently to physicochemical variations because they are distinct from each other in soluble speciation and mineral solubility, leading to precipitation at different times and localities during hydrothermal evolution.展开更多
THE southwestern Guizhou Province has been acknowledged as one of the most important and potentialgold producing areas in the People’ s Republic of China and has attracted world-wide attention since thediscovery of a...THE southwestern Guizhou Province has been acknowledged as one of the most important and potentialgold producing areas in the People’ s Republic of China and has attracted world-wide attention since thediscovery of a series of sediment-hosted micro-disseminated gold deposits in the last twenty years. Chertwidely occurs in the gold deposits. Study on geology and geochemistry of the chert may be important for abetter understanding of the forming condition and process of gold. 1 Characteristics of chert THE cherts are characterized by bedded, massived, pseudobrecciated and nodular structures, occurring insynsedimentary fault. The thickness of a chert bed generally varies from several meters to less than 20meters, with the maximum up to about 70 meters. Host elements are simple and concentrated in thecherts. The SiO<sub>2</sub> concentration of the cherts varies from 86.4 % to 95.64 %, 91.95% on average展开更多
文摘The dual geochemical character of paragenesis and fractionation between gold, arsenic and antimony in micro-disseminated gold deposits in southwestern Guizhou is discussed in terms of spatial distribution of independent deposits, lateral and vertical enrichment, mineralization stage and factor and correlation analyses. Thermodynamic calculations of solubility and speciation of gold and antimony minerals indicate that gold is transported in hydrothermal solution as Au(HS) 2and antimony is mainly as Sb(OH)30 although HSb2S4 may be of increasing importance in acidenvironment at low temperatures during the late stage of mineralization. Changes in physico-chemical conditions hold the key to the association and fractionation between gold and antimony. Gold and antimony response differently to physicochemical variations because they are distinct from each other in soluble speciation and mineral solubility, leading to precipitation at different times and localities during hydrothermal evolution.
文摘THE southwestern Guizhou Province has been acknowledged as one of the most important and potentialgold producing areas in the People’ s Republic of China and has attracted world-wide attention since thediscovery of a series of sediment-hosted micro-disseminated gold deposits in the last twenty years. Chertwidely occurs in the gold deposits. Study on geology and geochemistry of the chert may be important for abetter understanding of the forming condition and process of gold. 1 Characteristics of chert THE cherts are characterized by bedded, massived, pseudobrecciated and nodular structures, occurring insynsedimentary fault. The thickness of a chert bed generally varies from several meters to less than 20meters, with the maximum up to about 70 meters. Host elements are simple and concentrated in thecherts. The SiO<sub>2</sub> concentration of the cherts varies from 86.4 % to 95.64 %, 91.95% on average
