[en] Through the study of occurence, form, texture and composition of breccias in the area of No.670, the geological body in that area is considered to be formed by the magmatic intrusion and crypotoexplosion with the action of residual volcanic magma and hydrothermal fluid. By using this studied results of breccias formation, the uranium metallogenesis is also discussed

[en] The positions of the granite and sodium metasomatite, feature and zonation of metasomatic alteration minerals are analysed, and the composition character and evolution of alteration solution have been revealed. Controlling processes of sodium metasomatism and sodium metasomatite for uranium-beryllium mineralization are discussed. The granite was obviously superimposed and reformed by sodium carbonate hydrothermal solution in alteration zones. Based on the study of K-feldspar and its albitization, it is believed that the granitic magma is rich in Si an K. Albitization took place as a result of geological process of sodium-rich and calcium-rich hydrothermal fluid. At the early stage, with the disassociation of minerals a portion of uranium was derived from wall rocks (protolith) by hydrothermal solution. The main uranium mineralization occurred at the late stage of the continuous hydrothermal activities. Uranium was coprecipitated with metal sulfides

[en] The metallogenic geological setting, mineralized strata and rocks, mineralized fractures and characteristics of alteration and mineralization of 74 known deposits in Zhejiang Province are analysed. The fact that the uranium deposit in this region belongs to the filling uranium deposit of gas liquid metasomatism related to volcanic hydrothermal solution is proved. The mineralization was in late Yanshan. The metallogenic substances mainly came from sialic crust and the concentration of mineral-forming elements is closely related to magmatic differentiation. The deposits were formed under the circumstances of low temperature and low pressure in the shallow part of the crust

[en] The geological setting of the formation of the caldera classification of the volcanic rock cycles distribution laws of the strata facies and lithology as well as volcanofracture system are elucldated , and the evolutionary histroy of the caldera is dated

[en] The author presents the features of geological metallogenesis in uranium deposit of No. 199. The author has done research work on the alteration of country rock, the ore fabrics, the mineral paragenesis, geochemical feature, the occurrence of uranium and so on, and concluded that the mentioned uranium deposit belongs to hydrothermal uranium deposit amd later suffered from oxidation-infiltration. The uranium source of hydrothermal metallogenesis is mainly from the uranium-rich volcanic residual magma and hydrothermal fluid in late Yanshanian Period. Uranium is moved in the form of carbonic acid uranyl, the mineralization temperature of the uranium deposit is from 280 deg C to 340 deg C, the ore forming solution is weak acidity (PH = 5.33 ∼ 5.56), the fault of existing mineral is of the spreading characteristic, uranium source of infiltration concentration is from hydrothermal uranium mineralization, uranium exists in the form of secondary uranium minerals and adsorption, and is controlled by products of squeeze fracture--clay minerals and superficial minerals

[en] The author gives an uranium deposit example which relates directly to volcanic intrusion dormant explosion breccia in origin. The rock-forming characteristics and materials source of mineral-forming breccia are introduced in terms of petrology petrological chemistry and isotopes. The main geological features and mineral deposit origins of uranium deposit related to it are stated

[en] The author gives an uranium deposit example which relates directly to volcanic intrusion dormant explosion breccia in origin. The rock-forming characteristics and materials source of mineral-forming breccia are introduced in terms of petrology petrological chemistry and isotopes. The main geological features and mineral deposit origins of uranium deposit related to it are stated

[en] According to the formation geological setting of types of cementing material and texture feature of cryptoexplosion rock in mesozoic uranium-bearing volcanic area in west Zhejiang province, the cryptoexplosion can be classified into four groups and nine subgroups. Its formation mechanism is discussed. It is emphasized that the control of the explosion-split breccia and explosion-split rock of detrital type and hydrothermal type over uranium metallogenesis. The paper also points out the prospecting direction of uranium deposits of cryptoexplosion rock type

[en] The author summarizes characteristics of Mesozoic (Yangshanian Period) acid-intermediate volcanics, sub-volcanics and basic intrusive from aspects of formation time of rock series, petrogenic sequence, chemical composition, rock -controlling factors and petrogenic environments. It is suggested that these rocks were originated from different source areas of crust and mantle. Based on the time-space relation between different types uranium deposits and magmatic rocks, the author proposes that: the earlier stage (Earlier Cretaceous) U-hematite ores were originated from acid volcanic magmatism of crustal source, but the later stage (Late Cretaceous) pitchblende-polymetallic sulfide and pitchblende-purple fluorite rich ores were derived from basic magmatism of mantle source. Finally, the author proposes prospecting criteria of the above two types of uranium deposits

[en] The author analyses and concludes the main geological characteristics of Mengshan caldera and its control over uranium metallogenesis in area No. 670; demonstrates that the ore-hosting volcanic rocks are derived from the crust-mantle mixed source and mainly from the crustal source; approaches the uranium source, physicochemical condition of uranium metallogenesis and its formulation process in the uranium deposit of the area. It is considered that uranium deposit in this area can be synthesized into the genetic model of uraniferous hydrothermal solution of postmagmatic volcanic magma remelted from the uranium-enriched basement, its ore-forming materials are derived from the remelted magmatic differentiation and evolution and are precipitated to form the deposit in oxygen-rich, low temperature and tensile volcanic tectonics at near-surface