GENETIC MINERALOGY AND METALLOGENiC PROSPECTIVE PROGNOSITC OF XIAYINGFANG GOLD—POLYMETALLIC ORE DEPOSIT,CHINA

摘要

The Xiayingfang gold-po|ymetallic ore deposit is located in the northeast edge of the Longxumen Mesozoic fault basin in the northern margin of the North China platform.The Archean plagioclase-hornblende gneiss, proterozoic sedimentary rocks and Mesozoic volcanic-sedimentaryrocks widely spread over the area.The gold-polymetallic mineralization is generally related to Xiayingfang granitoid body that consists of early formed diorite-porphyrite,granite-porphyry,with copper mineralization and last formed rhyoporhyry. The rhyoporphyry has the close relationship to crypto-explosive breccia and to gold mineralization in time and genesis. The quartz-sericitization is the main alteration and is closely related to the gold mineralization. The K-feldsparation develops at early periods and occurs inside quartz-sericitization zone. The prominent ore mineral is merely pyrite, the secondary are chalcopyrite, galena, sphelarite, clinoedrite, magnetite, as well as native gold, and the minor minerals are molybdenite,