In 1994, geophysical work remained in depression in the aspect of solid ore resources, maintained a stable market in bydrologic, engineering and environmental survey, and grew continuously in oil and gas exploration. Subaerial three-dimensional seismic exploration exceeded 10000 km² for the first time; successful new experience was gained in three-dimensional seismic collection in high mountain a rcas and desert arcas; remarkable progress wasmade in three-dimensional processing. interpretation technique and software system of seismicdata; aerogeophysical work slightly picked up. Generally speaking, exploration geophysical methods obtained relatively few important new achievements in "hardware" (instrument and equipment), but made noticeable advances in "software" (theory, method, data-processing andinterpretation technique).

The relationship between the radioactive inert gas radon and lung cancer bas aroused much attention among people all over the world; as a result, re.earch work on radon in environment has been carried out in many countries. The distribution of parent elements of radon-uranium and radium-in geological environment has an intimate bearing on radon concentration in air. Therefore. a rapid and qualitative evaluation of radon concentration in air might be made through the study of uranium and radium distribution in geological environment.

The present paper describes the geopbysical prospecting method used in stereoscopic geological mapping of the Southeastern Hubei metallic ore district (the northwestern part of the Yangxinrock mass) and the geological ore-prospecting achievements thus gained. Through close coordination of geophy-sical and geological work and using integrated methods including gravity survey, magnetic survey and electrical sounding, the author obtained a series of new understanding in such aspects as the study of the structure and scape of the rock mass, the delineation of the ore-control structure and shape of the rock mass, the delineation of the ore-control structure and the ore prognosis. The stereoscopic geological map vividly exhibits the spatial geological characteristics of the Yangxin rock mass.The test on the ore-prospecting target area has demonstrated that geophysical prospecting is quite effective in stereoscopic geological mapping and can lead to accurate metallogenic prognosis.

The inversion of the lower interface of magnetic media on the basis of magnetic anomaly is a nonlinear problem. which it generally difficult to solve directly. Through lineatrzation of nonlinear problems. the authors established the linear discrete magnetic modeland, using regular algorithm of linear programing, designed a scheme for iterative solution,which does not require sverage depth of known interface relief, and only needs the auppositionthat the interface is continuous and that magnetism changes laterally. As the algorithm isready to exert physical constraint upon the solution. the method is characterized by rapidconvergence and high precision.

In the prospecting for the Median lead-zinc (silver) ore district. new theory and new methods were adopted, with which the ore district was developed from a local small deposit into a large-sized deposit. The present paper has studied its metallogeny as well as characteristics of its geophysical and geochemical fields. and summarized integrated oreprospecting criteria for Mexian type deposits. including deep tectonic setting, regionaltprognosis and ore district detailed investigation. In addition, the technical series for ore Prospecting are gived.

Based on an analysis of the distribution pattern of near source field, the present paper, using dual-frequency combination wave and taking into account specific conditions of exploration, has a dvanced an improved apparent resistivity of frequency domain electromagnetic sounding in near-field zone and given a definition formula of apparent resistivity.thus creating conditions for the performance of near-field frequency domain electromagneticsonnding.

Bsaed on underground md turface geochemical data and characteristics of regionalgeochemical field. the present paper has made oil-prospect evaluation of Lower YangtzeRegion. It is considered that the Upper Paleosoic Permian-Triassic System is the main targetbed for elploration and that. regionally. Taixing-Chaohu-Wangjiang area on the eastern side of the Tancheng-Lujiang fault should be selected as the main promising area for breakthrough in elploration. According to high content, complete components and sharp contrast ofhydrocarbon gases, geochemical achievements gained in thisarea can serve as reliable evidencefor evaluation of favorable areas of oil-gas accumulation.