POLYGENETIC MINERALIZATION OF THE EARLY PROTEROZOIC TONGKUANGYU METAPORPHYRY COPPER-DEPOSIT IN THE ZHONGTIAO-MOUNTAINS, SHANXI PROVINCE

The Tongkuangyu metaporphyry copper deposit formed in the Early Proter ozoic is tectonically located in the northern part of the Zhongtiao la mbda-type palaeorift depression, on the southern margin of the North C hina platform. The genesis of the deposit has long been a hot subject of research of geologists working on mineral deposits. By means of the protolith reconstruction and fluid inclusion and isotope studies of h ost rocks of the deposits, the authors hold that this deposit is the p roduct of combined exogenic, endogenic and metamorphic processes. Its formation mainly involved the following four stages: (1) the stage of formation of Mg- and Fe-rich tuffaceous variegated cupriferous sand-sh ale and K-rich biomodal volcanic rocks; (2) the early stage of formati on of the metaporphyry copper deposit; (3) the stage of formation of t he metaporphyry copper deposit; and (4) the stage of reworking of the metaporphyry copper deposit.