The synthetic information orefield-predicting model, a specialized model for 1:50000 ore prognosis, is studied in this paper. The basic train of thought, working procedure and some key technical problems (the establishment of geological conceptual model, extraction and synthesis of information, analysis of metallogenic regularity and compilation of model maps) for establishing the model are summarized. With case studies as examples, the paper points out that the establishment and application of such a model in1:50000 ore prognosis would considerably raise the reliability of ore prognosis.

With a contingent of 180,000 exploration geophysicists, China’s geophysical prospecting work occupies the forefront place in scale in the world and,as a result, large quantities of applied and research outcomes are being obtained every year. From cow oa, the Commission on Exploration Geophysics, Geological Society of China will write a review every year to report some major advances in exploration geophysics in the previous year,and this paper is the first one. It describes such subjects as aerogeophysics and oceanogeophysics, seism,geophysical logging and underground geophysics, ground electromagnetic method,*ground gravity and magnetic method, and ground gamma ennrgy spectra, and provides the number of field parties which were engaged in aerogeophysical and seismic exploration last year and the amount of work that was completed. Such data and some other statistical data are to be published every year.The paper also reports advances in techniques and applications of some major geophysical methods, but does not cover all the geophysical methods and their applications. Data show that seismic prospecting has been all along the most important geophysical method in China, whose significance is continuously increasing in other fields besides oil-gas exploration and whose techniques have made rapid progress. More and more importance is being attached to electromagnetic method by geophysicists in China. In the first part of this paper some present basic conditions of the exploration geophysical contingent are discussed with some statistical date given.

With the temperature logging at the Yangbajing shallow thermal field as an example, this paper analyses the temperature characteristics of the thermal field both in plan and in profile and investigates geological and hydrological implications of the temperature field of this thermal field in this region. It is also pointed out that the study of various shapes of temperature logging curves contributes to analysing geological structures and tracing the migration of thermal bodies and the route of run-off, and thus provides scientific grounds for reasonable arrangement of drilling.

This paper attempts to use natural gamma-ray logging data in the research of clay strata formed by volcanic events. The feasibility of this application is illustrated in the light of present technical level of natural gamma log-ging and contents of radiogenic elements in studied objects; the relations of material sources of sedimentary rocks with contents of radiogenic elements are analysed. Of all the uncommon sedimentary rocks, acidic volcaniolastic material and its hydrolyzates(clay)contain rather abundant radiogenic elements. With three types of volcanogenic clay rocks as examples, the natural gamma logging data are proved to be essential for finding and studying clay strata formed by volcanic events. Using this method, the author has found that there exists in Junlian area of southern Sichuan a layer of clay rocks between Permian and Triassic strata, which serves as the boundary of these two systems. Finally, some opinions are put forward concerning the ?future development of the natural gamma-ray logging technique.

The JWQ-3 Type single-aperture and double-aperture electromagnetic wave instruments developed by Institute of Expleration Geophysics and Geochemistry, China Academy of Geological Exploration Technology, were tentatively used by Chinese and Hungarian geophysicists in No. 1 bauxite district of Hungary from October 27 to November 11, 1987.The wall rocks of the bauxite is dolomite (lime stone), and there exists apparent difference in high-frequency electricity between ore and wall rock. Preliminary application shows that this method can disclose dolomite body between boreholes at an interval of 20-30m within the bauxite depesit, or discover fairly large blind bauxite orebody between dolomite boreholes at an interval of 40-60m.

In the light of simulation experiment, theoretical calculation and practical utilization, this paper deals emphatically with the application of magnetic method, electrical method and remote sensing technique to archaeological exploration, descrices its mechanism, means and effects, and proves the feasi-bility of applying geophysical prospecting to archaeological work. In view of the fact that geophysical archaeology is characterized by shallow depth and indistinction in physical properties, this paper also discusses the basic principles and methods for suppressing various interferences and raising resolution capability. Some preliminary views concerning the existent problems and the development trend of geophysical archaeology are also put forward for further discussion.

Geochemical characteristics of Se and Te in the Hetai gold deposit, have been studied in this paper. Se and Te usually occur as mineralizers and common elemeats in gold deposits, Although there are some papers dealing with Se and Te as indicator elements for gold deposits, systematic reports have been rarely seen. This paper investigated distribution of Se and Te i.n orebodies, wall rocks and soil of the Hetai gold deposits, found out preliminarily relations between Se, Te and gold mineralization, indicated ore-prospecting significance of thess two elemeats and gave guidance for further ore prospecting.

Based on experimentation on solution of samples, the author presents a method for analysing trace gold. The procedure is like this: the gold in the sample is dissolved at room temperature in 7% thiourea -15-20% sulfuric acid -1% hydrogen peroxide and 2g fluoride, and is enriched by foamed plastic loaded by active carbon, which is then ashed; gold in ashed materials is dissolved in hydrochloric acid-hydrogen peroxide, and colorimetric analysis is subsequently performed with improved bead separation method. In this way, gold content in the range of 0.001-10g/t can be determined for a sample 10g in weight. The method is extremely simple, convenient and sensitive, and can be conducted at the encampment of a reconnaissance team with the efficiency of determining 50 samples per day. As this method can avoid horrible smell given off when aqua regia is used to dissolve a sample, its application will surely have broad prospects.