Over the past ten years, remarkable progress has been made in geophysical prospecting, geochemical prospecting and iemote sensing work: new application fields have been opened up and extended, which have covered three great areas in geology, i. e. regional survey, reconnaissance of ore resources and hydrologic, engineering and environmental geology; a lot of good geological results have been obtained; fairly great improvement has been made in methods and techniques, some of which have reached international advanced level.During the eighth "Five-Year-Plan" period and the coming ten years, geophysical prospecting, geochemical prospecting and remote sensing should play their special role in such aspects as raising the level of geological survey, deepening the knowledge on geological settings of ore resources, improving the accuracy of ore prognosis, extending the exploration to greater depth and expanding services.In regional work, we should raise the coverage according to plan, carry out composite map compilation and deepen geological interpretation, thus givingguidance for solving some basic geological problems and conducting ore resource reconnaissance. In ore resource reconnaissance, we should systematically perform geophysical and geochemical survey in prospect areas of ore resources, pay more attention to anomaly reexamination, and raise our ability of finding concealed ore deposits and ore deposits which are difficult to recognize. In hydrologic, engineering and environmental survey,we should widen the survices of remote sensing and geophysical and geochemical prospecting, thus giving full reins to the role of these techniques.Technical advance depends on the progress made in such aspects as methods, techniques and equipments and the optimization of methods and techniques. In order to raise techniques to a markedly higher level, we should concentrate our research work on some most important subjects and timely revise technical standards, specifications and regulations.

In recent years, with the steady improvement and perfection in methods and techniques of gravity exploration in China's oil-gas survey, the effectiveness of gravity exploration is becoming more and more obvious and, as a result, its application fields are being extended with each passing day. In this paper, a brief description is given concerning some new advances gained in methods and techniques of gravity exploration in China's oil-gas survey. In addition, a review is made on the effectiveness of some practical methods.

In performing gas-prospecting work by means of neutron and density logging in strata with complicated lithology, one often meets with the trouble of multiple solutions caused by the disturbance of complicated lithology if the difference in neutron and density porosities is used alone to indicate gas zones. The logging gas-prospecting model, the calibration formula, the lower limit value of the gas zone and the criteria for verifying gas zones established in this paper have renewed the neutron and density logging gas-prospecting method and can repress the disturbance resulting from complex lithology, thus eliminating the possibility of multiple solutions. Case studies of logging gas-prospecting given in this paper demonstrate that the renewed method can indicate low porosity gas zones in strata with complicated lithology and improve the resolution, direct perceivability and piecision of this method, thus yielding better gas-prospecting results.

Based on geological study and integrated analysis of the 1:1,000,000 gravity and magnetic anomaly map for the northern margin of the North China platform, we hold that the northern margin of the North China platform is composed of three Archeozoic landmasses, i. e. Dongsheng, Chifeng and Liao-dong. Along the border areas of the three landmasses and near the deep fault zones within these landmasses there occur Late Archeozoic greenstone belts, suggesting that these three landmasses might have been linked with each other in Late Archeozoic-Early Proterozoic period (some 2500 Ma). Amarginal uplifted zone exists in the northern part of each landmass, but the discontinuity of the gravity and magnetic anomalous fields suggests the difference in the basement evolutionary history of these landmasses. Acomparison of orientations of fault zones inferred on the basis of gravity and magnetic anomalous fields in these three landmasses indicates that the relative movement between these landmasses must have proceeded along these deep fault zones.

Based on characteristics of accompanying metallic minerals and wall lock alterations in six large-sized or gigantic gold deposits (fields), this paper analyses the physical prerequisite for indirect gold prospecting by using IPmethod. With the ore-prospecting work conducted in such gold deposits as Jiapigou of Jilin, Jiaojia of eastern Shandong, and Ailaoshan of Yunnan as examples, the author describes briefly the effectiveness of IPmethod in gold prospecting as well as the unfavorable factors affecting its application. It is pointed out that, though of some limitations, the IPmethod remains a fairly effective geophysical prospecting method in search for gold deposits under favorable geological-geophysical conditions. In order to raise the rate of conect detection in gold prospecting, the IPmethod should be actively used in such aspects as the search for concealed and blind deposits, the inspection of geochemical anomalies and the 1:50000 integrated geophysical-geochemical prospecting in metallogenic provinces.

In geotechnical engineering and foundation handling, the wave velocity of shear wave is more important than that of compressional wave, but is less readily evaluated. It is therefore of practical significance to seek for an economical, simple and convenient, reliable and widely applicable in-situ test method. This paper describes the basic principle and working method of the transient wave test technique and its effectiveness in foundation handling and appraisal.

Water is a major agent for the migration of chemical elements, the substances dissolved in it affect its pHvalue, and its pHvalue, in turn, affects the behavior of element migration. The contents of chemical elements in water are governed by landscape conditions, but the mineralization type is a decisive factor of mineral association. With experimental results of two areas as examples, this paper demonstrates the reliability of the hydrochemical method in guiding ore prospecting work in areas with humid climate and heavy surface contamination, and also indicates its active role in ore-prospecting work of semiarid areas covered by eolian sand. Through study and summarization, hydrochemical indices for different mineraliza tion types have been determined, and the effectiveness of this method has been confirmed, together with the discovery of some promising areas for ore prospecting.

This paper deals with the application of 1:200,000 regional geochemicar reconnaissance data to agriculture and environment. Specifically, the study tries regionally to solve the problems of crop yields and endemic deseases.Our research work was carried out in Qinglong and (Sanhaignan sheets of Hebei Province. Acomparison of the distribution Pattern between elements in rocks, soils and stream sediments can regionally represent or reflect the fluctuation of elements in soils of the stream catchment. Investigation into the relation of crop yield and death rate in recent years to geochemical distribution of elements reveals that:(1) deficiency of Zn, Mo and Co in large areas of the sheets has to some extent exerted adverse effects on the increase in output of certain crops; (2) the low concentration of Mo in the environment coincides with the distribution of esophagus cancer, and the low concentration of Cr with hypertension and diabetes. Last but not least, it is pointed out that the potential threat of Cd, As and Pb anomalies in the upper reaches of Panjiakou reservoir which supplies drinking water for Tianjin City should be taken into account.According to the comparison and investigation, the normal range as well as the deficiency and excess limits of the elements in these sheets are preliminarily determined, and the environmental geochemical maps of Zn, Cu, Co, Mo and Cr are tentatively compiled.