The Shaxi porphyry copper (gold) deposits are a typical example of porphyry copper deposits associated with diorite in eastern China. Quartz diorite, which hosts the deposits, has a Rb-Sr isochron age of 127.9 ± ...The Shaxi porphyry copper (gold) deposits are a typical example of porphyry copper deposits associated with diorite in eastern China. Quartz diorite, which hosts the deposits, has a Rb-Sr isochron age of 127.9 ± 1.6 Ma. Geochemically, the rock is rich in alkalis (especially sodium), light rare earth elements (LREE) and large-ion lithophile elements (LILE), and has a relatively low initial strontium isotopic ratio (Isr=0.7058); thus it is the product of differentiation of crust-mantle mixing source magma. The model of alteration and mineralization zoning is similar to the Hollister (1974) diorite model. The ore fluids have a relatively high salinity and contain significant amounts of CO2, Ca2+, Na+ and ***CI?. The homogenization temperatures of fluid inclusions for the main mineralization stage range from 280 to 420°C, the δ18O values of the ore fluids vary from 3.51 to 5.52 %, the δD values are in the range between ?82.4 and ?59.8 %, the δ34S values of sulphides vary from ?0.3 to 2.49 %, and the δ13C values of CO2 in inclusions range between ?2.66 and ?6.53 %. Isotope data indicate that the hydrothermal ore fluids and ore substances of the Shaxi porphyry copper (gold) deposits were mainly derived from magmatic systems.展开更多
In China, there are 12 types of gold deposits in 57 class-Ill metallogenic zones, formed in 7 main metaUogenic periods. Most gold deposits are small or occur as ore spots; very large deposits are rare with relatively ...In China, there are 12 types of gold deposits in 57 class-Ill metallogenic zones, formed in 7 main metaUogenic periods. Most gold deposits are small or occur as ore spots; very large deposits are rare with relatively poor quality, mainly medium to low grade. Only 35% of the total gold reserves is identified, while a large amount of reserves is yet to be identified. In recent years, China Geological Survey has organized or conducted mineral resources survey and evaluation project, replacement resources prospecting for deposits in crisis, old mines prospecting and commercial prospecting funded or encouraged by the Central Government. These efforts have been fruitful. According to the temporal and spatial allocation of gold resources, and experiences from recent prospecting efforts, western China and the deep layers and peripheries of the-sits in eastern China have relatively high prospecting potential. The government should give even more support to the gold industry and strengthen technological innovation to help address difficulties in gold exploitation and processing. The government should also formulate consistent plans, consolidate mining rights, and promote integrated exploration, so as to achieve new major breakthroughs in gold prospecting. Gold is both a form of material wealth and a way of storing wealth. It is a rare resource with dual functions of commodity and currency. As an important global strategic asset and a cornerstone of financial reserves, gold plays an irreplaceable role in securing national economic development, maintaining financial security, strengthening national comprehensive power and promoting RMB internationalization. Based on latest research and prospecting results, the thesis proposes preliminary conclusions on types, temporal and spatial allocation, and exploration and development of gold deposits in China; predicts China＇s gold resource potential; reviews recent gold prospecting and exploration efforts; and, in the hope of offering some reference for the new round of gold prospecting, exploration and planning, offers some suggestions.展开更多
Utilizing theories of minerageny and prospecting mineralogy, the authors studied the attitude, morphotype and chemical composition of metallic minerals of pyrite, gold, chalcopyrite, galena and sphalerite, non-metalli...Utilizing theories of minerageny and prospecting mineralogy, the authors studied the attitude, morphotype and chemical composition of metallic minerals of pyrite, gold, chalcopyrite, galena and sphalerite, non-metallic minerals of quartz, carbonate, dolomite and rutile in the Puziwan gold deposit. The study shows the following results. （1） The mineral assemblage is complex and the species of sulfide are abundant with occurrences of sulfosalt minerals. （2） The composition in the minerals is complex and there rich micro elements, including As, Sb, Bi, Se, Te, Au, Ag, Cu, Pb, Zn, and Cr, Ni, V. The typomorphic characteristics of the association of the elements and their specific value suggest that gold mineralization is associated with shallow magmatic hydrothermal activity, the oreforming fluid is the mixture of abundant rising alkali magmatic water originating from the mantle or the lower crust and the descending acid atmospheric water. （3） Ankerite, Fe-rich sphalerite, granular Ti-rich rutile are widely distributed, which indicate great denudation depths, high mineralization temperature. The deposit is found in the middle and shallow positions of the porphyry series. The deep layers are not favorable for gold mineralization. （4） Copper minerals are rich in the ores and sulfides have high content of copper, suggesting possible porphyry-type Cu （Au） mineralization in deep positions and the surrounding areas.展开更多
文摘The Shaxi porphyry copper (gold) deposits are a typical example of porphyry copper deposits associated with diorite in eastern China. Quartz diorite, which hosts the deposits, has a Rb-Sr isochron age of 127.9 ± 1.6 Ma. Geochemically, the rock is rich in alkalis (especially sodium), light rare earth elements (LREE) and large-ion lithophile elements (LILE), and has a relatively low initial strontium isotopic ratio (Isr=0.7058); thus it is the product of differentiation of crust-mantle mixing source magma. The model of alteration and mineralization zoning is similar to the Hollister (1974) diorite model. The ore fluids have a relatively high salinity and contain significant amounts of CO2, Ca2+, Na+ and ***CI?. The homogenization temperatures of fluid inclusions for the main mineralization stage range from 280 to 420°C, the δ18O values of the ore fluids vary from 3.51 to 5.52 %, the δD values are in the range between ?82.4 and ?59.8 %, the δ34S values of sulphides vary from ?0.3 to 2.49 %, and the δ13C values of CO2 in inclusions range between ?2.66 and ?6.53 %. Isotope data indicate that the hydrothermal ore fluids and ore substances of the Shaxi porphyry copper (gold) deposits were mainly derived from magmatic systems.
文摘In China, there are 12 types of gold deposits in 57 class-Ill metallogenic zones, formed in 7 main metaUogenic periods. Most gold deposits are small or occur as ore spots; very large deposits are rare with relatively poor quality, mainly medium to low grade. Only 35% of the total gold reserves is identified, while a large amount of reserves is yet to be identified. In recent years, China Geological Survey has organized or conducted mineral resources survey and evaluation project, replacement resources prospecting for deposits in crisis, old mines prospecting and commercial prospecting funded or encouraged by the Central Government. These efforts have been fruitful. According to the temporal and spatial allocation of gold resources, and experiences from recent prospecting efforts, western China and the deep layers and peripheries of the-sits in eastern China have relatively high prospecting potential. The government should give even more support to the gold industry and strengthen technological innovation to help address difficulties in gold exploitation and processing. The government should also formulate consistent plans, consolidate mining rights, and promote integrated exploration, so as to achieve new major breakthroughs in gold prospecting. Gold is both a form of material wealth and a way of storing wealth. It is a rare resource with dual functions of commodity and currency. As an important global strategic asset and a cornerstone of financial reserves, gold plays an irreplaceable role in securing national economic development, maintaining financial security, strengthening national comprehensive power and promoting RMB internationalization. Based on latest research and prospecting results, the thesis proposes preliminary conclusions on types, temporal and spatial allocation, and exploration and development of gold deposits in China; predicts China＇s gold resource potential; reviews recent gold prospecting and exploration efforts; and, in the hope of offering some reference for the new round of gold prospecting, exploration and planning, offers some suggestions.
文摘Utilizing theories of minerageny and prospecting mineralogy, the authors studied the attitude, morphotype and chemical composition of metallic minerals of pyrite, gold, chalcopyrite, galena and sphalerite, non-metallic minerals of quartz, carbonate, dolomite and rutile in the Puziwan gold deposit. The study shows the following results. （1） The mineral assemblage is complex and the species of sulfide are abundant with occurrences of sulfosalt minerals. （2） The composition in the minerals is complex and there rich micro elements, including As, Sb, Bi, Se, Te, Au, Ag, Cu, Pb, Zn, and Cr, Ni, V. The typomorphic characteristics of the association of the elements and their specific value suggest that gold mineralization is associated with shallow magmatic hydrothermal activity, the oreforming fluid is the mixture of abundant rising alkali magmatic water originating from the mantle or the lower crust and the descending acid atmospheric water. （3） Ankerite, Fe-rich sphalerite, granular Ti-rich rutile are widely distributed, which indicate great denudation depths, high mineralization temperature. The deposit is found in the middle and shallow positions of the porphyry series. The deep layers are not favorable for gold mineralization. （4） Copper minerals are rich in the ores and sulfides have high content of copper, suggesting possible porphyry-type Cu （Au） mineralization in deep positions and the surrounding areas.
