海南岛金矿分布规律及成矿地质条件的初步研究

PRELIMINARY STUDY ON DISTRIBUTION PATTERNS AND METALLOGENIC GEOLOGIC CONDITIONS OF THE GOLD DEPOSITS IN HAINAN ISLAND

The gold deposits in Hainan island are divided into seven types in terms of the industrial utilization and host lithologies.They are(1)altered rock gold deposits occurring in fractured zones;(2)quartz vein gold deposits;(3)continental facies volcanic gold deposits;(4)stratiform veinlet-disseminated gold deposits;(5)skarn gold deposits;(6)polymetal-associated gold deposits;(7)modern placer.They distribute regularly in spaceBased on relation with major faulted zones,seven metallogenic belts can be determined in which four gold belts are extended in NE and NNE direction whereas others are in EW,NEE direction.Studies show that the deposits in the former four belts have generally a favourable source bed and are controled by long-term and repeated structures They are polygenesis deposits with large potential Caledonian metamorphic-migmatized hydrothermal activity and Hercynian Indo - China ductile shearing had played an impertant role in mineralization.On the contrary,the deposits in the latter three belts are simple genetically.They had mainly related with Yanshan magmatic and volcanic hydrothermal activities.Up till now,any larger gold deposit is still not discovered.However,there are indications that some area in the belts will possibly become gold-siver prospects.