in celebration of the 30th International Geological Congress to be held in Beijing,this paper aims atmaking known to our foreign colleagues the advances and achievements of geochemical exploration for solid ore resources in China: regional geochemical prospecting and medium-scale geochemical prospecting have covered 5170000 km² and some 900000 km² rmpectively, about 43000 geochemical anomalies of various sorts have been discovered and, on such a basis, 569 large-, medium-, and small-sized ore deposits with economic value havebeen found through anomaly appraisal and engineering inspection. The ore-prospecting effects are quite remarkableand, especially in geochemical prospecting of gold and silver deceits, achievements with breakthrough significancehave been obtained. Geochemical methods and techniques have been continuously improved and spread. China'sgeochemical prospecting has approached or reached international advanced level in several aspects such as field workmethods for special landscape areas, analytical methods and techniques for minor and trace elements, inspectionmethods for geochemical anomalies as well as processing and mapping of geochemical data.

The present paper makes a brief description of the progress of several main electric methods which havebeen developed quite rspidly since 1980's.They include induced polarization method,frequency spectrum IPmethod,trandient electromagnetic method, controlled-source audio-frequency magnetotelluric method and GPR.

This paper has dealt with the formation of metallic gases and metallic particles, the vertical transportation of geogas current,and the extensive existence of geogas dispersion haled around endogenetic metallic deposits. Adiscussion is also given on the prospects of applying geogas survey to the prospecting of concealed deposits and the exploration of rock types beneath transported overburden.

With nine aspects of evidence for vertical migration of hydrocarbon,the present paper has illustratedthe undoubted presence of vertical migration of hydrocarbon;based on work done by their institute in combinationwith information collected in China, the authors have made a brief summarization of the effectiveness of some individual methods currently used in oil and gas exploration, discussed the advantages of integrated geophysical geochemical prospecting methods, recounted the test results of optimization of integrated geophysical-geochemicalprospecting methods in the past ten years, and tentatively advanced the means for optimization of integrated geophysical-geochemical prospecting methods. Tests conducted in 10 areas demonstrate that the optimization meanscan yield Obvious geological effects.

Based on achievements gained in regional geochemical investigation conducted in Hangzhou-Jiaxing Huzhou plain, the authors carried out environmental geochemical research for the purpose of evaluating regional andcity (Hangzhou) environmental quality. The results show that regional environmrnt quality of this area and urbanenvironmental quality of Hangzhou City are good, and that various environmental quality districts quite satisfactorilyreflect their industrial production levels, population densities and history. Analytical study of vegetables from different environmental quality districts of Hangzhou City has proved that harmful elements in the polluted district ofHangzhou City have not yet affected human healty; nevertheless, importance should be attached to soil environmental protection to prevent harmful elements from exceeding standards.

The present paper has dealt with the application of the intensity of natural thermoluminescence fromthe near-surface soil samples to the search for oil and gas-bearing favorable target areas, described its method,principles and results of preliminary experiments, and compared the results obtained by this method with resultsgained by other geophysical prospecting methods.

In recent years, the development of nuclear technology and the change in understanding have led to theextensive application of ground gamma spectrometry and some other radiometric methods to geological mapping inChina.This paper has recounted the role and application of ground gamma spectrometry and some other radiometricmethods in geological mapping of China.

Based on experimental results,this paper has dealt with the mechanism and regularity governing thevariation of effective detection angle of GPR with the depth,the mechanism controlling the englargement of thewidth of the detected object on the GPR image and the method for its correction.

From Maxwell equation and according to the transmitting feature of high-frequency radar wave inmedia,the wave equation of radar signal is deduced,by which the imaging formula for perturbation of velocity is obtained, and velocity singularity of interface is analyzed by wavelet operator.In this way the imaging of the underground interface can be completed easily. Calculations prove that this new technique is effective.

This paper has discussed geological structure as well as geological conditions for concentration of underground thermal water and,with detailed and reliable geophysical data, indicated geological structure in unknown areas which is consistent with the geoelectric structure, thus providing scientific basis for geometric designing of wells.In addition, the paper has advanced a genetic model for underground thermal water in this area.