[en] This paper briefly presents the calculation method for gravity and magnetic remanence anomality and also discusses its application in studying geological structure and prospecting ore bodies

[en] On the general principle of the ratio between the anomalous area of the ore bed and the total area under the anomaly, a mathematical model is presented to calculate the density of uranium ore under the logging conditions. In addition, more detailed descriptions are given for determining the area S and S in the calculating formula, the methods of determining the various parameters and processing of their results. Compared the data detived from the model and the fields with the data from several other measurement, the error is very small, e.g. compared with whole tunnel method, the error is found less than 1%. It has been proved that the method is effective in determing the density of uranium ore when used under drilling condition

[en] The paragenesis of pyrite and pitchblende was formed under reduction state in the Fe(III) and U(VI) mixing solution. This process must be proceeded in the weakly acidic-neutral-alkali medium, as in the weakly acidic to neutral medium larger pyrite monocrystals are easy to be formed. When U(VI) solutions pass through pyrite zone under the high temperature and pressure conditions, new pyrite or marcasite will be produced and associated with pitchblende. When U(VI) is reduced by pyrite to form pitchblende, S(II) in the pyrite may serve as a reductant. Hematites are often in paragenesis with pitchblende, but they are products of different stages in hydrothermal lvolution process. Hematite occurred in the oxidation environment with high fuggacity of oxygen, while pitchblende occurred in the reduction environment with low fugacity of oxygen. Hematite was formed prior to pitchblende

[en] The sources for uranium metallogenesis in the area No. 303 are mainly from the northern, northeastern and northwestern parts to the basin and ore-bearing host-rock itself. Organic carbon is the main precipitant for uranium enrichement. Uranium mineralization occurs in the transitional zone of redox and weak reduction zone. The deposit belongs to a strata-bound uranium type which was formed dominantly in the process of diagenesis with ages ranging from 124 to 107 Ma

[en] Using the black and white air-photograph (at 1:60000 scale) 50 volcanic conduits have been interpreted, of which 26 conduits possess uranium mineralization in various sizes. The uranium mineralization in volcanic conduits is associated with the contacts of different lithologies and inter-breccia porosities

[en] The concentration, migration and distribution features of radioactive elements in the water and their relationship with chemical composition of the ground water are summarized. The significance of hydrochemical anomalies around uranium deposit No.706 and the methods for uranium exploration are discussed. In addition, based upon the hydrogeological data and migration pattern of Rn, the possibility of quantitative evaluation of spatial occurrance of buried uranium ore bodies is tentatively studied

[en] This paper describes the two important properties of the subdivision interpretation method of gamma-ray logging by deconvolution technique and demonstrates that the subdivision interpretation method by deconvolution technique and the current average concentration method are based on the same principle. Actually, the geologic impulse response parameter α has no overall effect on the interpretation result because the probable errors of the estimated uranium concentration for various layers caused by the uncertainty of parameter α are mutually compensated. The paper also indicates that the maximum logarithm gradient of th edifferential curves of anomalies will be the suitable value of the parameter α. In practice, the deconvolution technique using α = g_max can reduce the errors in estimated concentration of uranium and the netative estimated concentration of uranium can also be eliminated

[en] The preparation of thin film specimen and XRF method for uranium is described in this paper. The application of uranium M lines in XRF has advantage over correspanding L lines. The former has higher resolution, higher sensitivitys than the latter. Moreover the former has much lower background and higher ratio of peak to background. The detection limit (Cr target, PE crystal, 100 sec. conuting time) is 0.01 ppm

[en] Uranium deposit No.460 possesses not only considerable size, but also rich ores with a certain reserves. In this deposit the grade of uranium varies widely. Therer are two rich ore accumulation areas with high grade of uranium in the middle-depth and shallow parts of the deposit. The main geological factors for the formation and localization of rich ores in uranium deposit No.460 are the regional geological setting with high uranium content which resulted from two preconcentrations: the intersection of multiple sets of faulted structures with volcanic structures as well as mineralizing channel and the ore preservation conditions provided by the pre-ore hydromicazation; the mutual superposition of mineralization by hydrothermal alteration occurring during the late Yanshanian and Himalayan movements and only sufering from slight denudation and having fine conditons of ore preservation after mineralization

[en] In Tianshan region of Xinjaing, uranium mineralizations are frequently concertrated in some zones, where they essentially belong to same type. Evidently, this results from the control of a same geological metallogenetic process. By way of the geological interpretation of remote sensing image and the investigations in the field, and the digital image processing by computer for some subareas where uranium mineralizations are concentrated, a number of information about ore control regularity have been obtained, that are difficult to be available by general geological methods. Through the analysis of four uranium mineralization ares, the author suggests that favourable areas for search into a sedimentary-modification type of uranium mineralization are present in a variation locations of regional structural line in the transitional areas of platform and geosyncline, with the presence of circular structure constituted by the old stratum. And for search into the epigenetic uranium mineralization, it is necessary to particularly study the characteristics of geological structure on basin-margin and geomorphology. A multi-function combined processing will cause a goos result for the remote sensing image