The role of black shales in the formation of tin-polymetallic deposits in the eastern part of the dachang tin field, South China

摘要

Economic tin deposits in the eastern part of the Dachang tin field are hosted in a sedimentary sequence containing significant amounts of organic-matter in the form of black shales, that together with the younger granite intrusion, actively participated in the formation of Sn-polymetallic deposits. Field observations coupled with the new petrologic, mineralogical, inorganic and organic geochemical, isotopic and fluid inclusion data from the Dafulou, Huile and Kangma cassiterite-sulfide deposits have confirmed that black shales have played several important roles in their origin.